Bump versions to 0.12.1

Fix windows build
Bump versions to 0.12.0
2026-05-31 22:31:39 +01:00 · 2026-05-31 22:31:18 +01:00 · 2026-05-31 20:28:49 +01:00 · 2026-05-31 20:28:20 +01:00 · 2026-05-31 20:08:23 +01:00 · 2026-05-22 08:17:19 +01:00
24 changed files with 1509 additions and 696 deletions
--- a/.forgejo/workflows/check.yml
+++ b/.forgejo/workflows/check.yml
@ -0,0 +1,74 @@
 name: Check
 on:
  push:
    branches: ['main']
  pull_request:
    branches: ['main']
 env:
  CARGO_TERM_COLOR: always
  RUSTFLAGS: '-Dwarnings'
 jobs:
  build:
    runs-on: docker
    steps:
      - uses: actions/checkout@v4
      - name: Setup Node
        uses: actions/setup-node@v4
        with:
          node-version: '22.x'
          check-latest: true
      - name: Cache Rust dependencies
        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
            target/
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-
      - name: Cache npm dependencies
        uses: actions/cache@v4
        with:
          path: |
            reconcile-js/node_modules
            examples/website/node_modules
            ~/.npm
          key: >-
            ${{ runner.os }}-npm-${{
            hashFiles(
              'reconcile-js/package-lock.json',
              'examples/website/package-lock.json'
            )
            }}
          restore-keys: |
            ${{ runner.os }}-npm-
      - name: Install Rust toolchain
        run: |
          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
            | sh -s -- -y --default-toolchain none --profile minimal
          echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
      - name: Install uv
        run: |
          curl --proto '=https' --tlsv1.2 -LsSf https://astral.sh/uv/install.sh | sh
          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
      - name: Lint
        run: scripts/lint.sh
      - name: Test
        run: scripts/test.sh
      - name: Build website
        run: scripts/build-website.sh
--- a/.forgejo/workflows/publish.yml
+++ b/.forgejo/workflows/publish.yml
@ -0,0 +1,265 @@
 name: Publish
 on:
  push:
    branches: ['main']
    tags: ['*']
  workflow_dispatch:
 env:
  CARGO_TERM_COLOR: always
  RUSTFLAGS: '-Dwarnings'
 concurrency:
  group: 'pages'
  cancel-in-progress: false
 jobs:
  build:
    runs-on: docker
    steps:
      - uses: actions/checkout@v4
      - name: Setup Node
        uses: actions/setup-node@v4
        with:
          node-version: '22.x'
          check-latest: true
      - name: Cache Rust dependencies
        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
            target/
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-
      - name: Cache npm dependencies
        uses: actions/cache@v4
        with:
          path: |
            reconcile-js/node_modules
            examples/website/node_modules
            ~/.npm
          key: >-
            ${{ runner.os }}-npm-${{
            hashFiles(
              'reconcile-js/package-lock.json',
              'examples/website/package-lock.json'
            )
            }}
          restore-keys: |
            ${{ runner.os }}-npm-
      - name: Install Rust toolchain
        run: |
          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
            | sh -s -- -y --default-toolchain none --profile minimal
          echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
      - name: Install uv
        run: |
          curl --proto '=https' --tlsv1.2 -LsSf https://astral.sh/uv/install.sh | sh
          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
      - name: Lint
        run: scripts/lint.sh
      - name: Test
        run: scripts/test.sh
      - name: Build website
        run: scripts/build-website.sh
      - name: Deploy to pages mount
        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
        run: |
          apt-get update && apt-get install -y rsync
          rsync -a --delete examples/website/dist/ /pages/reconcile
  publish-crate:
    needs: build
    runs-on: docker
    if: startsWith(github.ref, 'refs/tags/')
    steps:
      - uses: actions/checkout@v4
      - name: Cache Rust dependencies
        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
            target/
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-
      - name: Install Rust toolchain
        run: |
          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
            | sh -s -- -y --default-toolchain none --profile minimal
          echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
      - name: Publish to crates.io
        run: cargo publish --token ${{ secrets.CRATES_IO_TOKEN }}
  publish-npm:
    needs: build
    runs-on: docker
    if: startsWith(github.ref, 'refs/tags/')
    steps:
      - uses: actions/checkout@v4
      - name: Setup Node
        uses: actions/setup-node@v4
        with:
          node-version: '22.x'
          check-latest: true
          registry-url: 'https://registry.npmjs.org'
      - name: Cache Rust dependencies
        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
            target/
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-
      - name: Cache npm dependencies
        uses: actions/cache@v4
        with:
          path: |
            reconcile-js/node_modules
            ~/.npm
          key: >-
            ${{ runner.os }}-npm-${{
            hashFiles('reconcile-js/package-lock.json')
            }}
          restore-keys: |
            ${{ runner.os }}-npm-
      - name: Install Rust toolchain
        run: |
          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
            | sh -s -- -y --default-toolchain none --profile minimal
          echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
      - name: Build website
        run: scripts/build-website.sh
      - name: Publish reconcile-js to NPM
        run: |
          cd reconcile-js
          cp ../README.md .
          npm publish
        env:
          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
  publish-pypi:
    needs: build
    runs-on: docker
    if: startsWith(github.ref, 'refs/tags/')
    steps:
      - uses: actions/checkout@v4
      - name: Cache Rust dependencies
        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
            target/
          key: ${{ runner.os }}-cargo-pypi-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-pypi-
            ${{ runner.os }}-cargo-
      # clang/lld/llvm provide clang-cl, lld-link and llvm-lib, which cargo-xwin
      # uses to cross-compile the Windows wheel from this Linux runner.
      - name: Install cross-compilation system dependencies
        run: |
          apt-get update
          apt-get install -y clang lld llvm
      - name: Install Rust toolchain
        run: |
          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
            | sh -s -- -y --default-toolchain none --profile minimal
          echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
      # The Linux targets ship in rust-toolchain.toml; add the cross targets.
      - name: Add cross-compilation Rust targets
        run: |
          rustup target add aarch64-unknown-linux-gnu x86_64-pc-windows-msvc
      # zig is the C toolchain maturin's `--zig` uses to produce manylinux2014
      # wheels with a pinned (old) glibc, independent of the runner's glibc.
      - name: Install zig
        run: |
          ZIG_VERSION=0.13.0
          curl --proto '=https' --tlsv1.2 -fLsS \
            "https://ziglang.org/download/${ZIG_VERSION}/zig-linux-x86_64-${ZIG_VERSION}.tar.xz" \
            | tar -xJ
          echo "$PWD/zig-linux-x86_64-${ZIG_VERSION}" >> "$GITHUB_PATH"
      - name: Install cargo-xwin
        run: command -v cargo-xwin || cargo install --locked cargo-xwin
      - name: Install uv
        run: |
          curl --proto '=https' --tlsv1.2 -LsSf https://astral.sh/uv/install.sh | sh
          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
      - name: Copy README
        run: cp README.md reconcile-python/
      - name: Build sdist
        working-directory: reconcile-python
        run: uv run maturin sdist --out dist
      - name: Build Linux x86_64 wheel
        working-directory: reconcile-python
        run: >-
          uv run maturin build --release --out dist
          --compatibility manylinux2014
          --target x86_64-unknown-linux-gnu --zig
      - name: Build Linux aarch64 wheel
        working-directory: reconcile-python
        run: >-
          uv run maturin build --release --out dist
          --compatibility manylinux2014
          --target aarch64-unknown-linux-gnu --zig
      - name: Build Windows x86_64 wheel
        working-directory: reconcile-python
        run: >-
          uv run maturin build --release --out dist
          --target x86_64-pc-windows-msvc
      # Forgejo cannot use PyPI trusted publishing (OIDC), so authenticate with
      # an API token. --skip-existing makes re-runs of a tag idempotent.
      - name: Publish to PyPI
        working-directory: reconcile-python
        env:
          MATURIN_PYPI_TOKEN: ${{ secrets.PYPI_TOKEN }}
        run: uv run maturin upload --skip-existing dist/*
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@ -1,26 +0,0 @@
 # To get started with Dependabot version updates, you'll need to specify which
 # package ecosystems to update and where the package manifests are located.
 # Please see the documentation for all configuration options:
 # https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
 version: 2
 updates:
  - package-ecosystem: 'cargo'
    directories: ['**']
    schedule:
      interval: 'daily'
  - package-ecosystem: 'github-actions'
    directories: ['**']
    schedule:
      interval: 'daily'
  - package-ecosystem: 'npm'
    directories: ['/reconcile-js', '/examples/website']
    schedule:
      interval: 'daily'
  - package-ecosystem: 'pip'
    directories: ['/reconcile-python']
    schedule:
      interval: 'daily'
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@ -1,197 +0,0 @@
 name: Check & publish
 on:
  push:
    branches: ['main']
    tags: ['*']
  pull_request:
    branches: ['main']
 env:
  CARGO_TERM_COLOR: always
  RUSTFLAGS: '-Dwarnings'
 jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
      - name: Setup Node.js environment
        uses: actions/setup-node@v6.3.0
        with:
          node-version: '22.x'
          check-latest: true
      - name: Install uv
        uses: astral-sh/setup-uv@v7
      - name: Cache Rust dependencies
        uses: actions/cache@v5
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
            target/
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-
      - name: Lint
        run: scripts/lint.sh
      - name: Test
        run: scripts/test.sh
  publish-crate:
    needs: build
    runs-on: ubuntu-latest
    if: startsWith(github.ref, 'refs/tags/')
    steps:
      - uses: actions/checkout@v6
      - name: Cache Rust dependencies
        uses: actions/cache@v5
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
            target/
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-
      - name: Publish to crates.io
        run: cargo publish --token ${{ secrets.CRATES_IO_TOKEN }}
  publish-npm:
    needs: build
    runs-on: ubuntu-latest
    if: startsWith(github.ref, 'refs/tags/')
    permissions:
      contents: read
      id-token: write
    steps:
      - uses: actions/checkout@v6
      - name: Setup Node.js environment
        uses: actions/setup-node@v6.3.0
        with:
          node-version: '24.x'
          check-latest: true
      - name: Cache Rust dependencies
        uses: actions/cache@v5
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
            target/
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-
      - name: Cache npm dependencies
        uses: actions/cache@v5
        with:
          path: |
            reconcile-js/node_modules
            ~/.npm
          key: ${{ runner.os }}-npm-${{ hashFiles('reconcile-js/package-lock.json') }}
          restore-keys: |
            ${{ runner.os }}-npm-
      - name: Build website
        run: scripts/build-website.sh
      - name: Publish reconcile-js to NPM
        run: |
          cd reconcile-js
          cp ../README.md .
          npm publish --access public
  build-python-wheels:
    needs: build
    if: startsWith(github.ref, 'refs/tags/')
    strategy:
      matrix:
        include:
          - os: ubuntu-latest
            target: x86_64
          - os: ubuntu-latest
            target: aarch64
          - os: macos-latest
            target: x86_64
          - os: macos-latest
            target: aarch64
          - os: windows-latest
            target: x86_64
    runs-on: ${{ matrix.os }}
    steps:
      - uses: actions/checkout@v6
      - uses: actions/setup-python@v6
        with:
          python-version: '3.x'
      - name: Copy README
        run: cp README.md reconcile-python/
      - uses: PyO3/maturin-action@v1
        with:
          target: ${{ matrix.target }}
          args: --release --out dist --find-interpreter
          manylinux: auto
          working-directory: reconcile-python
      - uses: actions/upload-artifact@v7
        with:
          name: wheels-${{ matrix.os }}-${{ matrix.target }}
          path: reconcile-python/dist/*.whl
  build-python-sdist:
    needs: build
    if: startsWith(github.ref, 'refs/tags/')
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
      - name: Copy README
        run: cp README.md reconcile-python/
      - uses: PyO3/maturin-action@v1
        with:
          command: sdist
          args: --out dist
          working-directory: reconcile-python
      - uses: actions/upload-artifact@v7
        with:
          name: sdist
          path: reconcile-python/dist/*.tar.gz
  publish-pypi:
    needs: [build-python-wheels, build-python-sdist]
    runs-on: ubuntu-latest
    permissions:
      id-token: write
    steps:
      - uses: actions/download-artifact@v8
        with:
          pattern: '{wheels-*,sdist}'
          merge-multiple: true
          path: dist
      - uses: pypa/gh-action-pypi-publish@release/v1
--- a/.github/workflows/gh-pages.yml
+++ b/.github/workflows/gh-pages.yml
@ -1,72 +0,0 @@
 name: Deploy Website to GitHub Pages
 on:
  push:
    branches:
      - main
  workflow_dispatch:
 # Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
 permissions:
  contents: read
  pages: write
  id-token: write
 # Allow only one concurrent deployment, skipping runs queued between the run in-progress and latest queued.
 # However, do NOT cancel in-progress runs as we want to allow these production deployments to complete.
 concurrency:
  group: 'pages'
  cancel-in-progress: false
 jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      contents: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v6
      - name: Cache Rust dependencies
        uses: actions/cache@v5
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
            target/
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-
      - name: Cache npm dependencies
        uses: actions/cache@v5
        with:
          path: |
            reconcile-js/node_modules
            ~/.npm
          key: ${{ runner.os }}-npm-${{ hashFiles('reconcile-js/package-lock.json') }}
          restore-keys: |
            ${{ runner.os }}-npm-
      - name: Build wasm
        run: |
          which wasm-pack || cargo install wasm-pack
          scripts/build-website.sh
      - name: Upload artifact
        uses: actions/upload-pages-artifact@v4
        with:
          path: examples/website/dist
  deploy:
    environment:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}
    runs-on: ubuntu-latest
    needs: build
    steps:
      - name: Deploy to GitHub Pages
        id: deployment
        uses: actions/deploy-pages@v5
--- a/.gitignore
+++ b/.gitignore
@ -10,5 +10,8 @@ node_modules
 # WebPack build output
 dist
 # Generated wasm-bindgen bundler + wasm2js output for the React Native build
 pkg-rn
 # Python virtual environment
 .venv
--- a/Cargo.lock
+++ b/Cargo.lock
@ -428,7 +428,7 @@ checksum = "f8dcc9c7d52a811697d2151c701e0d08956f92b0e24136cf4cf27b57a6a0d9bf"
 [[package]]
 name = "reconcile-text"
-version = "0.11.0"
+version = "0.12.1"
 dependencies = [
 "console_error_panic_hook",
 "diff-match-patch-rs",
--- a/Cargo.toml
+++ b/Cargo.toml
@ -1,7 +1,7 @@
 [package]
 name = "reconcile-text"
 description = "Intelligent 3-way text merging with automated conflict resolution"
-version = "0.11.0"
+version = "0.12.1"
 rust-version = "1.94"
 authors = ["Andras Schmelczer <andras@schmelczer.dev>"]
 edition = "2024"
--- a/README.md
+++ b/README.md
@ -80,6 +80,13 @@ console.log(result.text); // "Hi beautiful world"
 See the [example website source](examples/website/src/index.ts) for a more complex example, or the [advanced examples document](docs/advanced-ts.md).
 #### React Native (Hermes)
 React Native's default engine, Hermes, does not expose a runtime `WebAssembly`
 global, so the WebAssembly build cannot run there. For React Native, the package
 ships a pure-JavaScript build produced by [Binaryen's `wasm2js`](https://github.com/WebAssembly/binaryen)
 via its `react-native` entry point.
 ### Python
 Install via uv or pip:
--- a/docs/advanced-ts.md
+++ b/docs/advanced-ts.md
@ -2,40 +2,65 @@
 ## Edit Provenance
-Track which changes came from where using `reconcileWithHistory`:
+Track which changes came from where using `reconcileWithHistory`. The result's
 `history` field is typed as `SpanWithHistory[]`, and each span's `history` is a
 `History` string-literal union.
-```javascript
+```typescript
-const result = reconcileWithHistory(
+import { reconcileWithHistory, type History, type SpanWithHistory } from 'reconcile-text';
-  'Hello world',
+
-  'Hello beautiful world',
+const result = reconcileWithHistory('Hello world', 'Hello beautiful world', 'Hi world');
  'Hi world'
 );
 console.log(result.text); // "Hi beautiful world"
-console.log(result.history); /*
+
-[
+const history: SpanWithHistory[] = result.history;
-  {
+console.log(history);
-    "text": "Hello",
+// [
-    "history": "RemovedFromRight"
+//   { text: "Hello", history: "RemovedFromRight" },
-  },
+//   { text: "Hi", history: "AddedFromRight" },
-  {
+//   { text: " beautiful", history: "AddedFromLeft" },
-    "text": "Hi",
+//   { text: " ", history: "Unchanged" },
-    "history": "AddedFromRight"
+//   { text: "world", history: "Unchanged" },
-  },
+// ]
-  {
+
-    "text": " beautiful",
+const classByHistory = {
-    "history": "AddedFromLeft"
+  Unchanged: 'merge-unchanged',
-  },
+  AddedFromLeft: 'merge-added-left',
-  {
+  AddedFromRight: 'merge-added-right',
-    "text": " ",
+  RemovedFromLeft: 'merge-removed-left',
-    "history": "Unchanged"
+  RemovedFromRight: 'merge-removed-right',
-  },
+} satisfies Record<History, string>;
-  {
+```
-    "text": "world",
+
-    "history": "Unchanged"
+Using `satisfies Record<History, string>` keeps the object literal's values
 narrow while forcing every history case to be handled. If a future version adds
 another `History` value, TypeScript will point at this mapping.
 For control flow, use the same union as an exhaustiveness check:
 ```typescript
 import type { History } from 'reconcile-text';
 function historyLabel(history: History): string {
  switch (history) {
    case 'Unchanged':
      return 'unchanged';
    case 'AddedFromLeft':
      return 'added by left';
    case 'AddedFromRight':
      return 'added by right';
    case 'RemovedFromLeft':
      return 'removed from left';
    case 'RemovedFromRight':
      return 'removed from right';
    default:
      return assertNever(history);
  }
 }
 function assertNever(value: never): never {
  throw new Error(`Unhandled history value: ${value}`);
 }
 ]
 */
 ```
 ## Tokenisation Strategies
@ -45,26 +70,162 @@ console.log(result.history); /*
 - **Word tokeniser** (`"Word"`) - Splits on word boundaries (recommended for prose)
 - **Character tokeniser** (`"Character"`) - Individual characters (fine-grained control)
 - **Line tokeniser** (`"Line"`) - Line-by-line (similar to `git merge` or more precisely [`git merge-file`](https://git-scm.com/docs/git-merge-file))
 - **Markdown tokeniser** (`"Markdown"`) - Splits on Markdown structural boundaries (headings, list items, paragraphs)
 ```typescript
 import { reconcile, type BuiltinTokenizer } from 'reconcile-text';
 const tokenizers = [
  'Word',
  'Character',
  'Line',
  'Markdown',
 ] as const satisfies readonly BuiltinTokenizer[];
 const result = reconcile('abc', 'axc', 'abyc', 'Character');
 console.log(result.text); // "axyc"
 for (const tokenizer of tokenizers) {
  const merged = reconcile(
    '# Title\n\n- old item\n',
    '# Title\n\n- old item\n- left item\n',
    '# New title\n\n- old item\n',
    tokenizer
  );
  console.log(tokenizer, merged.text);
 }
 ```
 ## Cursor Tracking
-`reconcile-text` automatically tracks cursor positions through merges, which is useful for collaborative editors. Selections can be tracked by providing them as a pair of cursors.
+`reconcile-text` automatically tracks cursor positions through merges, which is
 useful for collaborative editors. Selections can be tracked by providing them as
 a pair of cursors.
-```javascript
+```typescript
-const result = reconcile(
+import { reconcile, type TextWithOptionalCursors } from 'reconcile-text';
-  'Hello world',
+
-  {
+const left = {
  text: 'Hello beautiful world',
  cursors: [{ id: 1, position: 6 }], // After "Hello "
-  },
+} satisfies TextWithOptionalCursors;
-  {
+
 const right = {
  text: 'Hi world',
  cursors: [{ id: 2, position: 0 }], // At the beginning
-  }
+} satisfies TextWithOptionalCursors;
-);
+
 const result = reconcile('Hello world', left, right);
 // Result: "Hi beautiful world" with repositioned cursors
 console.log(result.text); // "Hi beautiful world"
 console.log(result.cursors); // [{ id: 2, position: 0 }, { id: 1, position: 3 }]
 ```
 > The `cursors` list is sorted by character position (not IDs).
 ## Generic Helpers and Inference
 The exported merge functions are intentionally small: they merge strings, or
 strings plus cursor metadata. In TypeScript applications, keep domain-specific
 metadata in your own typed wrappers and let inference preserve the surrounding
 shape.
 ```typescript
 import { reconcile, type BuiltinTokenizer } from 'reconcile-text';
 type ReconciledText<T extends { text: string }> = Omit<T, 'text'> & {
  text: string;
 };
 function reconcileDraft<TDraft extends { text: string }>(
  parent: TDraft,
  left: TDraft,
  right: TDraft,
  tokenizer?: BuiltinTokenizer
 ): ReconciledText<TDraft> {
  return {
    ...right,
    text: reconcile(parent.text, left.text, right.text, tokenizer).text,
  };
 }
 interface MarkdownDraft {
  id: string;
  text: string;
  updatedAt: Date;
 }
 const parent: MarkdownDraft = {
  id: 'intro',
  text: '# Title\n\nOld text\n',
  updatedAt: new Date('2026-01-01T00:00:00Z'),
 };
 const left: MarkdownDraft = {
  ...parent,
  text: '# Title\n\nOld text\n\n- left note\n',
 };
 const right: MarkdownDraft = {
  ...parent,
  text: '# New title\n\nOld text\n',
 };
 const merged = reconcileDraft(parent, left, right, 'Markdown');
 // merged is inferred as { id: string; updatedAt: Date; text: string }
 ```
 Use `satisfies` for configuration objects and cursor payloads when you want
 compile-time checking without widening everything to the library interface.
 ```typescript
 import type { BuiltinTokenizer, TextWithOptionalCursors } from 'reconcile-text';
 const mergeOptions = {
  tokenizer: 'Markdown',
  renderDeletedSpans: true,
 } satisfies {
  tokenizer: BuiltinTokenizer;
  renderDeletedSpans: boolean;
 };
 const documentWithSelection = {
  text: 'Hello beautiful world',
  cursors: [
    { id: 1, position: 6 },
    { id: 2, position: 15 },
  ],
 } satisfies TextWithOptionalCursors;
 ```
 ## Compact Diffs
 Generate and apply compact diff representations. The TypeScript type is
 `Array<number | string>` for `diff()` and `Array<number | bigint | string>` for
 `undiff()`, because the underlying WebAssembly layer may represent integer
 entries as `bigint`.
 ```typescript
 import { diff, undiff } from 'reconcile-text';
 const original = 'Hello world';
 const changed = 'Hello beautiful world';
 // Generate a compact diff
 const changes = diff(original, changed);
 console.log(changes); // [5, " beautiful world"]
 // Reconstruct the changed text from the diff
 const reconstructed = undiff(original, changes);
 console.assert(reconstructed === changed);
 ```
 Diff entries are positive integers (retain N characters), negative integers
 (delete N characters), and strings (insert text).
 ## Complete Example
 For a complete browser example that renders `SpanWithHistory` values and cursor
 selections, see the [example website source](../examples/website/src/index.ts).
--- a/examples/website/package-lock.json
+++ b/examples/website/package-lock.json
@ -28,11 +28,12 @@
    },
    "../../reconcile-js": {
      "name": "reconcile-text",
-      "version": "0.11.0",
+      "version": "0.12.1",
      "dev": true,
      "license": "MIT",
      "devDependencies": {
        "@types/jest": "^30.0.0",
        "binaryen": "^123.0.0",
        "jest": "^30.3.0",
        "prettier": "^3.8.1",
        "reconcile-text": "file:../pkg",
@ -1135,6 +1136,7 @@
      "integrity": "sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw==",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "bin": {
        "acorn": "bin/acorn"
      },
@ -1175,6 +1177,7 @@
      "integrity": "sha512-PlXPeEWMXMZ7sPYOHqmDyCJzcfNrUr3fGNKtezX14ykXOEIvyK81d+qydx89KY5O71FKMPaQ2vBfBFI5NHR63A==",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "fast-deep-equal": "^3.1.3",
        "fast-uri": "^3.0.1",
@ -1411,6 +1414,7 @@
        }
      ],
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "baseline-browser-mapping": "^2.9.0",
        "caniuse-lite": "^1.0.30001759",
@ -3976,6 +3980,7 @@
        }
      ],
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "nanoid": "^3.3.11",
        "picocolors": "^1.1.1",
@ -4484,6 +4489,7 @@
      "integrity": "sha512-+4N/u9dZ4PrgzGgPlKnaaRQx64RO0JBKs9sDhQ2pLgN6JQZ25uPQZKQYaBJU48Kd5BxgXoJ4e09Dq7nMcOUW3A==",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "chokidar": "^4.0.0",
        "immutable": "^5.1.5",
@ -5303,6 +5309,7 @@
      "integrity": "sha512-M7BAV6Rlcy5u+m6oPhAPFgJTzAioX/6B0DxyvDlo9l8+T3nLKbrczg2WLUyzd45L8RqfUMyGPzekbMvX2Ldkwg==",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "engines": {
        "node": ">=12"
      },
@ -5386,7 +5393,8 @@
      "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.8.1.tgz",
      "integrity": "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w==",
      "dev": true,
-      "license": "0BSD"
+      "license": "0BSD",
      "peer": true
    },
    "node_modules/tsyringe": {
      "version": "4.10.0",
@ -5428,6 +5436,7 @@
      "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
      "dev": true,
      "license": "Apache-2.0",
      "peer": true,
      "bin": {
        "tsc": "bin/tsc",
        "tsserver": "bin/tsserver"
@ -5568,6 +5577,7 @@
      "integrity": "sha512-jTywjboN9aHxFlToqb0K0Zs9SbBoW4zRUlGzI2tYNxVYcEi/IPpn+Xi4ye5jTLvX2YeLuic/IvxNot+Q1jMoOw==",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "@types/eslint-scope": "^3.7.7",
        "@types/estree": "^1.0.8",
@ -5617,6 +5627,7 @@
      "integrity": "sha512-MfwFQ6SfwinsUVi0rNJm7rHZ31GyTcpVE5pgVA3hwFRb7COD4TzjUUwhGWKfO50+xdc2MQPuEBBJoqIMGt3JDw==",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "@discoveryjs/json-ext": "^0.6.1",
        "@webpack-cli/configtest": "^3.0.1",
--- a/reconcile-js/package-lock.json
+++ b/reconcile-js/package-lock.json
@ -1,15 +1,16 @@
 {
  "name": "reconcile-text",
-  "version": "0.11.0",
+  "version": "0.12.1",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "reconcile-text",
-      "version": "0.11.0",
+      "version": "0.12.1",
      "license": "MIT",
      "devDependencies": {
        "@types/jest": "^30.0.0",
        "binaryen": "^123.0.0",
        "jest": "^30.3.0",
        "prettier": "^3.8.1",
        "reconcile-text": "file:../pkg",
@ -24,7 +25,7 @@
    },
    "../pkg": {
      "name": "reconcile-text",
-      "version": "0.11.0",
+      "version": "0.12.1",
      "dev": true,
      "license": "MIT"
    },
@ -65,6 +66,7 @@
      "version": "7.28.0",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "@ampproject/remapping": "^2.2.0",
        "@babel/code-frame": "^7.27.1",
@ -1656,6 +1658,7 @@
      "integrity": "sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw==",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "bin": {
        "acorn": "bin/acorn"
      },
@ -1682,6 +1685,7 @@
      "integrity": "sha512-PlXPeEWMXMZ7sPYOHqmDyCJzcfNrUr3fGNKtezX14ykXOEIvyK81d+qydx89KY5O71FKMPaQ2vBfBFI5NHR63A==",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "fast-deep-equal": "^3.1.3",
        "fast-uri": "^3.0.1",
@ -1908,6 +1912,24 @@
        "node": ">=6.0.0"
      }
    },
    "node_modules/binaryen": {
      "version": "123.0.0",
      "resolved": "https://registry.npmjs.org/binaryen/-/binaryen-123.0.0.tgz",
      "integrity": "sha512-/hls/a309aZCc0itqP6uhoR+5DsKSlJVfB8Opd2BY9Ndghs84IScTunlyidyF4r2Xe3lQttnfBNIDjaNpj6mTw==",
      "dev": true,
      "license": "Apache-2.0",
      "bin": {
        "wasm-as": "bin/wasm-as",
        "wasm-ctor-eval": "bin/wasm-ctor-eval",
        "wasm-dis": "bin/wasm-dis",
        "wasm-merge": "bin/wasm-merge",
        "wasm-metadce": "bin/wasm-metadce",
        "wasm-opt": "bin/wasm-opt",
        "wasm-reduce": "bin/wasm-reduce",
        "wasm-shell": "bin/wasm-shell",
        "wasm2js": "bin/wasm2js"
      }
    },
    "node_modules/brace-expansion": {
      "version": "1.1.12",
      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.12.tgz",
@ -1950,6 +1972,7 @@
        }
      ],
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "baseline-browser-mapping": "^2.9.0",
        "caniuse-lite": "^1.0.30001759",
@ -3053,6 +3076,7 @@
      "integrity": "sha512-AkXIIFcaazymvey2i/+F94XRnM6TsVLZDhBMLsd1Sf/W0wzsvvpjeyUrCZD6HGG4SDYPgDJDBKeiJTBb10WzMg==",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "@jest/core": "30.3.0",
        "@jest/types": "30.3.0",
@ -4936,6 +4960,7 @@
      "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
      "dev": true,
      "license": "Apache-2.0",
      "peer": true,
      "bin": {
        "tsc": "bin/tsc",
        "tsserver": "bin/tsserver"
@ -5072,6 +5097,7 @@
      "integrity": "sha512-jTywjboN9aHxFlToqb0K0Zs9SbBoW4zRUlGzI2tYNxVYcEi/IPpn+Xi4ye5jTLvX2YeLuic/IvxNot+Q1jMoOw==",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "@types/eslint-scope": "^3.7.7",
        "@types/estree": "^1.0.8",
@ -5119,6 +5145,7 @@
      "version": "6.0.1",
      "dev": true,
      "license": "MIT",
      "peer": true,
      "dependencies": {
        "@discoveryjs/json-ext": "^0.6.1",
        "@webpack-cli/configtest": "^3.0.1",
--- a/reconcile-js/package.json
+++ b/reconcile-js/package.json
@ -1,9 +1,10 @@
 {
  "name": "reconcile-text",
-  "version": "0.11.0",
+  "version": "0.12.1",
  "description": "Intelligent 3-way text merging with automated conflict resolution",
  "main": "dist/reconcile.node.js",
  "browser": "dist/reconcile.web.js",
  "react-native": "dist/reconcile.rn.js",
  "keywords": [
    "text editing",
    "sync",
@ -31,12 +32,13 @@
    "dist/**/*"
  ],
  "scripts": {
-    "build": "webpack --mode production",
+    "build": "node scripts/build-rn.mjs && webpack --mode production",
-    "format": "prettier --write \"./**/*.(ts|scss|json|html)\"",
+    "format": "prettier --write \"./**/*.(ts|mjs|scss|json|html)\"",
    "test": "NODE_OPTIONS=\"$NODE_OPTIONS --experimental-vm-modules\" jest"
  },
  "devDependencies": {
    "@types/jest": "^30.0.0",
    "binaryen": "^123.0.0",
    "jest": "^30.3.0",
    "prettier": "^3.8.1",
    "reconcile-text": "file:../pkg",
--- a/reconcile-js/scripts/build-rn.mjs
+++ b/reconcile-js/scripts/build-rn.mjs
@ -0,0 +1,307 @@
 // Generates `pkg-rn/`: a React Native / Hermes-compatible build of the
 // wasm-bindgen bindings in which the WebAssembly module is replaced by its
 // wasm2js (pure-JS) translation.
 import { execFileSync } from 'node:child_process';
 import { existsSync, readdirSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
 import { dirname, resolve } from 'node:path';
 import { fileURLToPath, pathToFileURL } from 'node:url';
 import { homedir } from 'node:os';
 const here = dirname(fileURLToPath(import.meta.url));
 const reconcileJsDir = resolve(here, '..');
 const repoRoot = resolve(reconcileJsDir, '..');
 const releaseWasm = resolve(
  repoRoot,
  'target/wasm32-unknown-unknown/release/reconcile_text.wasm'
 );
 const outDir = resolve(reconcileJsDir, 'pkg-rn');
 const bgWasm = resolve(outDir, 'reconcile_text_bg.wasm');
 const bgWasmJs = resolve(outDir, 'reconcile_text_bg.wasm.js');
 const loweredWasm = resolve(outDir, '_lowered.wasm');
 const entryJs = resolve(outDir, 'reconcile_text.js');
 const wasmOpt = resolve(reconcileJsDir, 'node_modules/.bin/wasm-opt');
 const wasm2js = resolve(reconcileJsDir, 'node_modules/.bin/wasm2js');
 function run(cmd, args) {
  execFileSync(cmd, args, { stdio: 'inherit' });
 }
 // Locate the wasm-bindgen CLI. It MUST match the `wasm-bindgen` crate version pinned
 // in Cargo.toml: a mismatched CLI emits bindings the runtime can't use. So we resolve
 // the required version first and verify every candidate against it, failing loudly
 // rather than silently falling back to whatever other version happens to be around.
 function findWasmBindgen() {
  const cargoToml = readFileSync(resolve(repoRoot, 'Cargo.toml'), 'utf8');
  const wanted = cargoToml.match(
    /wasm-bindgen\s*=\s*\{[^}]*version\s*=\s*"([^"]+)"/
  )?.[1];
  if (!wanted) {
    throw new Error(
      '[build-rn] Could not parse the pinned wasm-bindgen version from Cargo.toml, so ' +
        'the required CLI version is unknown. Has the dependency declaration changed?'
    );
  }
  // 1. On PATH: accept it only if its version matches the pin.
  let onPath = null;
  try {
    onPath = execFileSync('which', ['wasm-bindgen'], { encoding: 'utf8' }).trim();
  } catch {
    /* not on PATH; try the wasm-pack cache next */
  }
  if (onPath) {
    const version = execFileSync(onPath, ['--version'], { encoding: 'utf8' }).match(
      /\d+\.\d+\.\d+/
    )?.[0];
    if (version !== wanted) {
      throw new Error(
        `[build-rn] wasm-bindgen on PATH (${onPath}) is ${version ?? 'an unknown version'}, ` +
          `but Cargo.toml pins ${wanted}. Install the matching CLI ` +
          `(\`cargo install wasm-bindgen-cli --version ${wanted}\`) or remove the mismatched one.`
      );
    }
    return onPath;
  }
  const cacheRoots = [
    resolve(homedir(), 'Library/Caches/.wasm-pack'),
    resolve(homedir(), '.cache/.wasm-pack'),
  ];
  for (const root of cacheRoots) {
    if (!existsSync(root)) {
      continue;
    }
    for (const entry of readdirSync(root)) {
      const candidate = resolve(root, entry, 'wasm-bindgen');
      if (!existsSync(candidate)) {
        continue;
      }
      let version;
      try {
        version = execFileSync(candidate, ['--version'], { encoding: 'utf8' }).match(
          /\d+\.\d+\.\d+/
        )?.[0];
      } catch {
        continue; // not an invokable wasm-bindgen; ignore
      }
      if (version === wanted) {
        return candidate;
      }
    }
  }
  throw new Error(
    `[build-rn] No wasm-bindgen ${wanted} found on PATH or in the wasm-pack cache. ` +
      'Run `wasm-pack build --target web --features wasm` first (it caches the matching ' +
      `wasm-bindgen), or \`cargo install wasm-bindgen-cli --version ${wanted}\`.`
  );
 }
 if (!existsSync(releaseWasm)) {
  throw new Error(
    `Missing ${releaseWasm}.\nRun \`wasm-pack build --target web --features wasm\` from the repo root first.`
  );
 }
 console.log('[build-rn] generating bundler-target bindings with wasm-bindgen');
 rmSync(outDir, { recursive: true, force: true });
 const wasmBindgen = findWasmBindgen();
 run(wasmBindgen, ['--target', 'bundler', '--out-dir', outDir, releaseWasm]);
 // --- Patch wasm-bindgen's cached-memory getters for wasm2js -----------------
 //
 // wasm-bindgen caches typed-array / DataView views over `wasm.memory.buffer` and
 // only re-creates them when it detects the heap grew. It detects a grow by looking
 // for ArrayBuffer *detachment*: a real `WebAssembly.Memory.grow()` detaches the old
 // buffer (its `byteLength` becomes 0 and `.detached` becomes true), and those are the
 // only signals the generated getters check:
 //   - getUint8ArrayMemory0(): refreshes when `byteLength === 0`           (detach only)
 //   - getDataViewMemory0():   refreshes when `.detached === true`, OR when the buffer
 //     identity changed but only `if (.detached === undefined)` — i.e. that identity
 //     fallback runs solely on engines lacking `ArrayBuffer.prototype.detached`.
 //
 // wasm2js grows differently: `__wasm_memory_grow` (in reconcile_text_bg.wasm.js)
 // allocates a NEW ArrayBuffer, copies the old heap into it, and reassigns
 // `memory.buffer` WITHOUT ever detaching the old buffer. So the old buffer keeps
 // `byteLength > 0` and `.detached === false`, and on modern engines that DO expose
 // `ArrayBuffer.prototype.detached` (Node 25+, current Hermes) the identity fallback is
 // gated off. Net effect: after a grow the getters keep returning views over the stale
 // pre-grow buffer, silently corrupting any operation large enough to grow the heap.
 // Small inputs never grow, so this escapes naive testing.
 //
 // WHY WE PATCH INSTEAD OF CONFIGURING.
 // This is not fixed or configurable upstream: wasm-bindgen has no wasm2js / asm.js /
 // React Native / "no-WebAssembly" target (every target assumes real WebAssembly
 // detach-on-grow semantics), there is no flag to force buffer-identity comparison, and
 // the getter-generation logic (crates/cli-support/src/js/mod.rs `memview`) is
 // byte-for-byte identical from the pinned 0.2.114 through the latest release and
 // `main`. The non-detaching-grow case is not even a tracked upstream issue. Rewriting
 // the generated glue is therefore the only available fix: the two replacements below
 // make BOTH getters also refresh on a buffer-identity change
 // (`buffer !== wasm.memory.buffer`), which is the one signal wasm2js does give.
 //
 // Each replacement is asserted independently. If a future wasm-bindgen reshapes one
 // getter but not the other, we MUST fail the build rather than ship a half-patched
 // module whose un-patched getter corrupts large inputs. The post-build self-test at
 // the bottom of this file is the backstop that proves the result survives a real grow.
 const bgJsPath = resolve(outDir, 'reconcile_text_bg.js');
 let bgJs = readFileSync(bgJsPath, 'utf8');
 // (1) Uint8Array getter: append an unconditional buffer-identity check to the
 //     `byteLength === 0` detach guard (upstream has no identity check here at all).
 const byteLengthGuard = /(cached\w*Memory0)\.byteLength === 0/g;
 const byteLengthHits = bgJs.match(byteLengthGuard)?.length ?? 0;
 if (byteLengthHits === 0) {
  throw new Error(
    `[build-rn] Could not find the Uint8Array \`byteLength === 0\` growth guard in ` +
      `${bgJsPath} to patch for wasm2js. The wasm-bindgen output shape changed; update ` +
      'this patch (see crates/cli-support/src/js/mod.rs `memview`) — do NOT ship an ' +
      'unpatched getter, it will corrupt large inputs under wasm2js.'
  );
 }
 bgJs = bgJs.replace(
  byteLengthGuard,
  '$1.byteLength === 0 || $1.buffer !== wasm.memory.buffer'
 );
 // (2) DataView getter: drop the `detached === undefined &&` prefix so the existing
 //     buffer-identity check runs on every runtime, not only legacy ones.
 const gatedGuard =
  /(cached\w*Memory0)\.buffer\.detached === undefined && \1\.buffer !== wasm\.memory\.buffer/g;
 const gatedHits = bgJs.match(gatedGuard)?.length ?? 0;
 if (gatedHits === 0) {
  throw new Error(
    `[build-rn] Could not find the DataView \`detached === undefined\`-gated buffer-identity ` +
      `check in ${bgJsPath} to un-gate for wasm2js. The wasm-bindgen output shape changed; ` +
      'update this patch (see crates/cli-support/src/js/mod.rs `memview`) — do NOT ship an ' +
      'unpatched getter, it will corrupt large inputs under wasm2js.'
  );
 }
 bgJs = bgJs.replace(gatedGuard, '$1.buffer !== wasm.memory.buffer');
 writeFileSync(bgJsPath, bgJs);
 // Post-MVP features that wasm2js cannot translate must be lowered to MVP first.
 // reference-types stays enabled: it only covers the funcref table here, which
 // wasm2js handles via call_indirect.
 const featureFlags = [
  '--enable-bulk-memory',
  '--enable-sign-ext',
  '--enable-nontrapping-float-to-int',
  '--enable-mutable-globals',
  '--enable-reference-types',
 ];
 console.log('[build-rn] optimising and lowering to MVP with wasm-opt');
 run(wasmOpt, [
  ...featureFlags,
  '-O3',
  '--signext-lowering',
  '--llvm-memory-copy-fill-lowering',
  '--llvm-nontrapping-fptoint-lowering',
  bgWasm,
  '-o',
  loweredWasm,
 ]);
 console.log('[build-rn] translating wasm -> JS with wasm2js');
 run(wasm2js, ['--enable-reference-types', loweredWasm, '-o', bgWasmJs]);
 console.log('[build-rn] wiring the JS translation into reconcile_text.js');
 const entry = readFileSync(entryJs, 'utf8');
 const rewired = entry.replace(
  /from\s+(['"])\.\/reconcile_text_bg\.wasm\1/,
  'from $1./reconcile_text_bg.wasm.js$1'
 );
 if (rewired === entry) {
  throw new Error(
    `Could not find the \`./reconcile_text_bg.wasm\` import in ${entryJs}; ` +
      'the wasm-bindgen bundler output layout may have changed.'
  );
 }
 writeFileSync(entryJs, rewired);
 // The binary and the intermediate are no longer referenced; remove them so no
 // bundler attempts to instantiate WebAssembly from this directory.
 rmSync(bgWasm, { force: true });
 rmSync(loweredWasm, { force: true });
 // Mark the directory as ESM (matching the web `pkg/`) so Node and Jest treat
 // these `.js` files as modules. `sideEffects` stays true because importing the
 // entry runs `__wbg_set_wasm(...)`, which must not be tree-shaken away.
 writeFileSync(
  resolve(outDir, 'package.json'),
  JSON.stringify({ type: 'module', sideEffects: true }, null, 2) + '\n'
 );
 // Backstop: import the freshly generated module and prove it survives a heap grow.
 // The patches above are matched by regex against wasm-bindgen output; a silently
 // mis-applied patch (or a wasm-bindgen change we matched too loosely) would leave a
 // getter reading the stale pre-grow buffer and corrupt large inputs only. Rather than
 // trust the regexes, we force a grow here and assert a byte-exact round-trip, so a
 // broken bundle fails the build instead of reaching a React Native consumer.
 async function selfTest() {
  // Importing the entry runs `__wbg_set_wasm(...)`, initialising the wasm2js module.
  const api = await import(pathToFileURL(entryJs).href);
  // Same module instance (Node caches by resolved path), so this `memory` is the heap
  // the API operates on; its `.buffer` getter reflects the current (post-grow) buffer.
  const { memory } = await import(pathToFileURL(bgWasmJs).href);
  // ~100 KB of distinct tokens. The diff working set amplifies the input many-fold
  // (a ~50 KB input already forces dozens of grows), so this reliably grows the heap
  // well past wasm2js's ~1 MB initial allocation while staying fast. A tiny parent
  // keeps the edit distance — and therefore the runtime — small.
  const tokens = [];
  for (let i = 0; i < 10000; i++) {
    tokens.push(`token-${i}`);
  }
  const target = tokens.join(' ');
  const parent = 'reconcile self-test';
  const heapBefore = memory.buffer.byteLength;
  // Stale post-grow reads surface either as an out-of-bounds throw or as silently
  // wrong bytes, so handle both: a throw here is itself the failure signal.
  let roundTripped;
  try {
    const changed = new api.TextWithCursors(target, []);
    const compact = api
      .diff(parent, changed, 'Word')
      // This build's `undiff` rejects BigInt; normalise exactly as src/core.ts does.
      .map((item) => (typeof item === 'bigint' ? Number(item) : item));
    changed.free();
    roundTripped = api.undiff(parent, compact, 'Word');
  } catch (cause) {
    throw new Error(
      '[build-rn] self-test crashed during a large diff/undiff round-trip (after the heap ' +
        'grew). This is the signature of unpatched wasm2js cached-memory getters reading the ' +
        'stale pre-grow buffer. The growth patch is not taking effect. Refusing to ship this ' +
        'React Native bundle.',
      { cause }
    );
  }
  const heapAfter = memory.buffer.byteLength;
  if (heapAfter <= heapBefore) {
    throw new Error(
      `[build-rn] self-test did not grow the wasm heap (stayed at ${heapBefore} bytes), ` +
        'so it cannot validate the memory-growth patch. Enlarge the self-test input.'
    );
  }
  if (roundTripped !== target) {
    throw new Error(
      '[build-rn] self-test FAILED: diff/undiff round-trip did not match after a heap grow. ' +
        'The patched wasm2js cached-memory getters are returning stale/corrupt data — the ' +
        'growth patch is not taking effect. Refusing to ship this React Native bundle.'
    );
  }
 }
 console.log('[build-rn] self-testing the patched module (forces a heap grow)');
 await selfTest();
 console.log('[build-rn] done -> pkg-rn/');
--- a/reconcile-js/src/core.ts
+++ b/reconcile-js/src/core.ts
@ -0,0 +1,400 @@
 // Shared, platform-agnostic wrapper around the generated wasm-bindgen surface.
 //
 // The actual wasm bindings are injected by a platform-specific entrypoint:
 //   - `index.ts`     (web/node) instantiates the real WebAssembly module lazily
 //                    on first use via `initSync`.
 //   - `index.rn.ts`  (React Native / Hermes) links a wasm2js (pure-JS)
 //                    implementation, since Hermes does not expose a runtime
 //                    `WebAssembly` global. See `scripts/build-rn.mjs`.
 type WasmModule = typeof import('reconcile-text');
 /**
 * The generated wasm-bindgen surface this library wraps, plus a hook to make
 * sure the underlying module is ready. Supplied by a platform entrypoint.
 */
 export interface WasmBackend {
  CursorPosition: WasmModule['CursorPosition'];
  TextWithCursors: WasmModule['TextWithCursors'];
  reconcile: WasmModule['reconcile'];
  reconcileWithHistory: WasmModule['reconcileWithHistory'];
  diff: WasmModule['diff'];
  undiff: WasmModule['undiff'];
  /**
   * Make the wasm module ready for use. Invoked before every operation, so it
   * must be cheap and idempotent (a no-op once initialised).
   */
  ensureReady(): void;
 }
 // Define the enum values as a const array to avoid duplication
 const BUILTIN_TOKENIZERS = ['Character', 'Line', 'Markdown', 'Word'] as const;
 /**
 * Tokenisation strategies for text merging.
 *
 * These correspond to the built-in tokenizers available in the underlying WASM module.
 */
 export type BuiltinTokenizer = (typeof BUILTIN_TOKENIZERS)[number];
 /**
 * History classification for text spans in merge results.
 *
 * Indicates the origin of each text span in the merged document.
 */
 export type History =
  | 'Unchanged'
  | 'AddedFromLeft'
  | 'AddedFromRight'
  | 'RemovedFromLeft'
  | 'RemovedFromRight';
 /**
 * Represents a text document with associated cursor positions.
 *
 * This interface is used both as input to reconcile functions (to specify where
 * cursors are positioned in the original documents) and as output (with cursors
 * automatically repositioned after merging).
 */
 export interface TextWithCursors {
  /** The document's entire content as a string */
  text: string;
  /**
   * Array of cursor positions within the text. Can be empty if there are no cursors to track.
   * Each cursor has a unique ID and position.
   */
  cursors: CursorPosition[];
 }
 /**
 * Like `TextWithCursors`, but cursors may be null or undefined (treated as empty).
 * Used as input where cursor tracking is optional.
 */
 export interface TextWithOptionalCursors {
  /** The document's entire content as a string */
  text: string;
  /**
   * Array of cursor positions within the text. Can be null, undefined, or empty
   * if there are no cursors to track. Each cursor has a unique ID and position.
   */
  cursors: null | undefined | CursorPosition[];
 }
 /**
 * Represents a cursor position within a text document.
 *
 * Cursors are automatically repositioned during text merging to maintain their
 * relative positions as text is inserted, deleted, or modified around them.
 */
 export interface CursorPosition {
  /** Unique identifier for the cursor (can be any number, must be unique within the document) */
  id: number;
  /** Character position in the text, 0-based index from the beginning of the document */
  position: number;
 }
 /**
 * Represents a merged text document with cursor positions and detailed change history.
 *
 * This is the return type of `reconcileWithHistory()` and provides complete information
 * about how the merge was performed, including which parts of the final text came from
 * which source documents.
 */
 export interface TextWithCursorsAndHistory {
  /** The merged document's entire content */
  text: string;
  /**
   * Array of cursor positions within the merged text. Can be empty if there are no cursors to track.
   * All cursors are automatically repositioned from the left and right documents.
   */
  cursors: CursorPosition[];
  /**
   * Detailed provenance information showing the origin of each text span in the result.
   * Each span indicates whether it was unchanged, added from left, added from right, etc.
   */
  history: SpanWithHistory[];
 }
 /**
 * Represents a span of text in the merged result with its change history.
 *
 * This shows exactly which source document contributed each piece of text to the
 * final merged result. Useful for understanding merge decisions and creating
 * visualisations of how documents were combined.
 */
 export interface SpanWithHistory {
  /** The text content of this span */
  text: string;
  /** The origin of this text span in the merge result */
  history: History;
 }
 /** The public, synchronous API surface, identical across platforms. */
 export interface ReconcileApi {
  /**
   * Merges three versions of text using intelligent conflict resolution.
   *
   * This is the primary function for 3-way text merging. Unlike traditional merge tools
   * that produce conflict markers, this function automatically resolves conflicts by
   * applying both sets of changes where possible.
   *
   * @param original - The original/base version of the text that both sides diverged from
   * @param left - The left version of the text (either string or TextWithCursors with cursor positions)
   * @param right - The right version of the text (either string or TextWithCursors with cursor positions)
   * @param tokenizer - The tokenisation strategy: "Word" (default, recommended for prose),
   *                    "Character" (fine-grained), "Line" (similar to git merge), or
   *                    "Markdown" (splits on Markdown structure)
   * @returns The reconciled text with automatically repositioned cursor positions
   *
   * @example
   * ```typescript
   * const original = "Hello world";
   * const left = "Hello beautiful world";    // Added "beautiful"
   * const right = "Hi world";                // Changed "Hello" to "Hi"
   *
   * const result = reconcile(original, left, right);
   * console.log(result.text); // "Hi beautiful world"
   * ```
   */
  reconcile(
    original: string,
    left: string | TextWithOptionalCursors,
    right: string | TextWithOptionalCursors,
    tokenizer?: BuiltinTokenizer
  ): TextWithCursors;
  /**
   * Generates a compact diff representation between an original and changed text.
   *
   * These can be parsed and unpacked using the `undiff` function or the Rust crate's EditedText::from_diff.
   * Cursor positions are omitted from the diff result.
   *
   * This function computes the differences between two versions of text and returns
   * a compact representation of those changes.
   *
   * @param original - The original/base version of the text
   * @param changed - The modified version of the text (either string or TextWithCursors with cursor positions)
   * @param tokenizer - The tokenisation strategy, which is the same as used in `reconcile`.
   * @returns An array of inserts (strings), deletes (negative integers), and retained spans (positive integers).
   */
  diff(
    original: string,
    changed: string | TextWithOptionalCursors,
    tokenizer?: BuiltinTokenizer
  ): Array<number | string>;
  /**
   * Applies a compact diff to an original text to reconstruct the changed version.
   *
   * This function takes an original text and a compact diff representation (as produced
   * by the `diff` function) and reconstructs the modified text.
   *
   * @param original - The original/base version of the text
   * @param diff - The compact diff array (inserts as strings, deletes as negative integers, retained spans as positive integers)
   * @param tokenizer - The tokenisation strategy, which is the same as used in `reconcile`.
   * @returns The reconstructed changed text as a string.
   */
  undiff(
    original: string,
    diff: Array<number | bigint | string>,
    tokenizer?: BuiltinTokenizer
  ): string;
  /**
   * Merges three versions of text and returns detailed provenance information.
   *
   * This function behaves like `reconcile()` but also provides
   * detailed historical information about the origin of each text span in the result.
   * This is valuable for understanding how the merge was performed and which changes
   * came from which source.
   *
   * Note: Computing the history is computationally more expensive than the basic merge.
   *
   * @param original - The original/base version of the text that both sides diverged from
   * @param left - The left version of the text (either string or TextWithCursors with cursor positions)
   * @param right - The right version of the text (either string or TextWithCursors with cursor positions)
   * @param tokenizer - The tokenisation strategy: "Word" (default, recommended for prose),
   *                    "Character" (fine-grained), "Line" (similar to git merge), or
   *                    "Markdown" (splits on Markdown structure)
   * @returns The reconciled text with cursor positions and detailed change history
   *
   * @example
   * ```typescript
   * const original = "Hello world";
   * const left = "Hello beautiful world";
   * const right = "Hi world";
   *
   * const result = reconcileWithHistory(original, left, right);
   * console.log(result.text); // "Hi beautiful world"
   * console.log(result.history); // Array of SpanWithHistory objects showing change origins
   * ```
   */
  reconcileWithHistory(
    original: string,
    left: string | TextWithOptionalCursors,
    right: string | TextWithOptionalCursors,
    tokenizer?: BuiltinTokenizer
  ): TextWithCursorsAndHistory;
 }
 const UNSUPPORTED_TOKENIZER_ERROR = `Unsupported tokenizer, only ${BUILTIN_TOKENIZERS.join(
  ', '
 )} are supported`;
 /**
 * Build the public {@link ReconcileApi} on top of a {@link WasmBackend}.
 *
 * Each operation calls `backend.ensureReady()` first, then marshals JS values
 * into the wasm representation, invokes the binding, and frees the wasm-side
 * objects. The behaviour is identical regardless of whether the backend is a
 * real WebAssembly module or its wasm2js translation.
 */
 export function makeReconcileApi(backend: WasmBackend): ReconcileApi {
  function assertTokenizer(tokenizer: BuiltinTokenizer): void {
    if (!BUILTIN_TOKENIZERS.includes(tokenizer)) {
      throw new Error(UNSUPPORTED_TOKENIZER_ERROR);
    }
  }
  function toWasmTextWithCursors(text: string | TextWithOptionalCursors) {
    const isInputString = typeof text === 'string';
    const innerText = isInputString ? text : text.text;
    const innerCursors = isInputString ? [] : (text.cursors ?? []);
    return new backend.TextWithCursors(
      innerText,
      innerCursors.map(({ id, position }) => new backend.CursorPosition(id, position))
    );
  }
  function toTextWithCursors(textWithCursor: {
    text(): string;
    cursors(): Array<{ id(): number; characterIndex(): number; free(): void }>;
  }): TextWithCursors {
    const wasmCursors = textWithCursor.cursors();
    const cursors = wasmCursors.map((cursor) => ({
      id: cursor.id(),
      position: cursor.characterIndex(),
    }));
    for (const cursor of wasmCursors) {
      cursor.free();
    }
    return {
      text: textWithCursor.text(),
      cursors,
    };
  }
  function toSpanWithHistory(span: {
    text(): string;
    history(): History;
    free(): void;
  }): SpanWithHistory {
    const result = {
      text: span.text(),
      history: span.history(),
    };
    span.free();
    return result;
  }
  function reconcile(
    original: string,
    left: string | TextWithOptionalCursors,
    right: string | TextWithOptionalCursors,
    tokenizer: BuiltinTokenizer = 'Word'
  ): TextWithCursors {
    backend.ensureReady();
    assertTokenizer(tokenizer);
    const leftCursor = toWasmTextWithCursors(left);
    const rightCursor = toWasmTextWithCursors(right);
    const result = backend.reconcile(original, leftCursor, rightCursor, tokenizer);
    leftCursor.free();
    rightCursor.free();
    const jsResult = toTextWithCursors(result);
    result.free();
    return jsResult;
  }
  function diff(
    original: string,
    changed: string | TextWithOptionalCursors,
    tokenizer: BuiltinTokenizer = 'Word'
  ): Array<number | string> {
    backend.ensureReady();
    assertTokenizer(tokenizer);
    const changedWasm = toWasmTextWithCursors(changed);
    const result = backend.diff(original, changedWasm, tokenizer);
    changedWasm.free();
    return result.map((item) => (typeof item === 'bigint' ? Number(item) : item));
  }
  function undiff(
    original: string,
    diffValue: Array<number | bigint | string>,
    tokenizer: BuiltinTokenizer = 'Word'
  ): string {
    backend.ensureReady();
    assertTokenizer(tokenizer);
    // The real-WebAssembly backend's `diff` emits BigInt spans, whereas the
    // wasm2js (React Native) backend rejects BigInt outright. Normalise to
    // plain numbers - exactly as `diff` does on the way out - so a `diff`
    // result round-trips through `undiff` identically on every platform.
    return backend.undiff(
      original,
      diffValue.map((item) => (typeof item === 'bigint' ? Number(item) : item)),
      tokenizer
    );
  }
  function reconcileWithHistory(
    original: string,
    left: string | TextWithOptionalCursors,
    right: string | TextWithOptionalCursors,
    tokenizer: BuiltinTokenizer = 'Word'
  ): TextWithCursorsAndHistory {
    backend.ensureReady();
    assertTokenizer(tokenizer);
    const leftCursor = toWasmTextWithCursors(left);
    const rightCursor = toWasmTextWithCursors(right);
    const result = backend.reconcileWithHistory(
      original,
      leftCursor,
      rightCursor,
      tokenizer
    );
    leftCursor.free();
    rightCursor.free();
    const jsResult = toTextWithCursors(result);
    const history = result.history().map(toSpanWithHistory);
    result.free();
    return {
      ...jsResult,
      history,
    };
  }
  return { reconcile, diff, undiff, reconcileWithHistory };
 }
--- a/reconcile-js/src/index.rn.ts
+++ b/reconcile-js/src/index.rn.ts
@ -0,0 +1,47 @@
 // React Native entrypoint (resolved via the `react-native` package field).
 //
 // Hermes — the default React Native engine since RN 0.84 / Expo SDK 56 — does
 // not expose a runtime `WebAssembly` global, so the normal `new
 // WebAssembly.Module(...)` path used by `index.ts` throws
 // `ReferenceError: Property 'WebAssembly' doesn't exist`.
 //
 // Instead we link a wasm2js translation of the module: pure JavaScript that
 // needs no `WebAssembly` global and is instantiated synchronously at import
 // time. The public API and its synchronous signatures are unchanged, so
 // callers need no modification. The `pkg-rn` directory is generated by
 // `scripts/build-rn.mjs`.
 import {
  CursorPosition as wasmCursorPosition,
  TextWithCursors as wasmTextWithCursors,
  reconcile as wasmReconcile,
  reconcileWithHistory as wasmReconcileWithHistory,
  diff as wasmDiff,
  undiff as wasmUndiff,
 } from '../pkg-rn/reconcile_text.js';
 import { makeReconcileApi, type WasmBackend } from './core';
 const backend: WasmBackend = {
  CursorPosition: wasmCursorPosition,
  TextWithCursors: wasmTextWithCursors,
  reconcile: wasmReconcile,
  reconcileWithHistory: wasmReconcileWithHistory,
  diff: wasmDiff,
  undiff: wasmUndiff,
  // The wasm2js module initialises itself at import time, so this is a no-op.
  ensureReady() {},
 };
 export const { reconcile, diff, undiff, reconcileWithHistory } =
  makeReconcileApi(backend);
 export type {
  BuiltinTokenizer,
  History,
  CursorPosition,
  TextWithCursors,
  TextWithOptionalCursors,
  TextWithCursorsAndHistory,
  SpanWithHistory,
 } from './core';
--- a/reconcile-js/src/index.test.ts
+++ b/reconcile-js/src/index.test.ts
@ -1,4 +1,5 @@
-import { reconcile, reconcileWithHistory, diff, undiff } from './index';
+import * as webApi from './index';
 import * as rnApi from './index.rn';
 import { installWasmLeakDetector, checkForWasmLeaks } from './wasm-leak-detector';
 import * as fs from 'fs';
 import * as path from 'path';
@ -17,7 +18,18 @@ afterEach(() => {
  }
 });
-describe('reconcile', () => {
+// `./index` is the web/node build (real WebAssembly); `./index.rn` is the React
 // Native build (the wasm2js pure-JS translation). Both are thin backends over the
 // same `src/core.ts` wrapper and expose an identical public API, so the behavioural
 // suite below runs against both to guarantee they stay in lock-step.
 const backends = [
  { name: 'web/node (WebAssembly)', api: webApi },
  { name: 'React Native (wasm2js)', api: rnApi },
 ];
 describe.each(backends)('reconcile [$name]', ({ api }) => {
  const { reconcile, reconcileWithHistory, diff, undiff } = api;
  it('call reconcile without cursors', () => {
    expect(reconcile('Hello', 'Hello world', 'Hi world').text).toEqual('Hi world');
  });
@ -60,9 +72,26 @@ describe('reconcile', () => {
    expect(result.text).toEqual('Hi world');
    expect(result.history.length).toBeGreaterThan(0);
  });
  it('undiff accepts bigint entries (per the Array<number | bigint | string> type)', () => {
    const original = 'Hello world';
    const changed = 'Hello cruel world';
    // `diff` returns plain numbers; emulate a caller that supplies BigInt, which the
    // public signature permits. The wasm2js build rejects raw BigInt, so the shared
    // wrapper must normalise it — running this on both backends asserts the contract.
    const withBigints = diff(original, changed).map((item) =>
      typeof item === 'number' ? BigInt(item) : item
    );
    expect(withBigints.some((item) => typeof item === 'bigint')).toBe(true);
    expect(undiff(original, withBigints)).toEqual(changed);
  });
 });
-describe('test_diff_and_undiff_are_inverse', () => {
+describe.each(backends)('diff and undiff are inverse [$name]', ({ api }) => {
  const { diff, undiff } = api;
  const resourcesPath = path.join(__dirname, '../../tests/resources');
  const readFileSlice = (fileName: string, start: number, end: number): string => {
@ -93,3 +122,31 @@ describe('test_diff_and_undiff_are_inverse', () => {
    });
  });
 });
 // React-Native-only: Hermes exposes no `WebAssembly` global, which is the whole reason
 // the RN entry point links a wasm2js build. Only the wasm2js backend can satisfy this.
 describe('React Native (wasm2js) Hermes parity', () => {
  const { reconcile, reconcileWithHistory, diff, undiff } = rnApi;
  it('runs every operation with no WebAssembly global', () => {
    const descriptor = Object.getOwnPropertyDescriptor(globalThis, 'WebAssembly');
    delete (globalThis as { WebAssembly?: unknown }).WebAssembly;
    try {
      expect((globalThis as { WebAssembly?: unknown }).WebAssembly).toBeUndefined();
      expect(reconcile('Hello', 'Hello world', 'Hi world').text).toEqual('Hi world');
      const changes = diff('Hello world', 'Hello cruel world');
      expect(undiff('Hello world', changes)).toEqual('Hello cruel world');
      expect(
        reconcileWithHistory('Hello', 'Hello world', 'Hi world').history.length
      ).toBeGreaterThan(0);
    } finally {
      // Restore the global so the leak check and later suites are unaffected.
      if (descriptor) {
        Object.defineProperty(globalThis, 'WebAssembly', descriptor);
      }
    }
  });
 });
--- a/reconcile-js/src/index.ts
+++ b/reconcile-js/src/index.ts
@ -1,8 +1,7 @@
 import {
  CursorPosition as wasmCursorPosition,
  reconcile as wasmReconcile,
  TextWithCursors as wasmTextWithCursors,
-  SpanWithHistory as wasmSpanWithHistory,
+  reconcile as wasmReconcile,
  reconcileWithHistory as wasmReconcileWithHistory,
  diff as wasmDiff,
  undiff as wasmUndiff,
@ -11,290 +10,18 @@ import {
 import wasmBytes from 'reconcile-text/reconcile_text_bg.wasm';
-// Define the enum values as const arrays to avoid duplication
+import { makeReconcileApi, type WasmBackend } from './core';
 const BUILTIN_TOKENIZERS = ['Character', 'Line', 'Markdown', 'Word'] as const;
 const HISTORY_VALUES = [
  'Unchanged',
  'AddedFromLeft',
  'AddedFromRight',
  'RemovedFromLeft',
  'RemovedFromRight',
 ] as const;
 /**
 * Tokenisation strategies for text merging.
 *
 * These correspond to the built-in tokenizers available in the underlying WASM module.
 */
 export type BuiltinTokenizer = (typeof BUILTIN_TOKENIZERS)[number];
 /**
 * History classification for text spans in merge results.
 *
 * Indicates the origin of each text span in the merged document.
 */
 export type History = (typeof HISTORY_VALUES)[number];
 /**
 * Represents a text document with associated cursor positions.
 *
 * This interface is used both as input to reconcile functions (to specify where
 * cursors are positioned in the original documents) and as output (with cursors
 * automatically repositioned after merging).
 */
 export interface TextWithCursors {
  /** The document's entire content as a string */
  text: string;
  /**
   * Array of cursor positions within the text. Can be empty if there are no cursors to track.
   * Each cursor has a unique ID and position.
   */
  cursors: CursorPosition[];
 }
 /**
 * Like `TextWithCursors`, but cursors may be null or undefined (treated as empty).
 * Used as input where cursor tracking is optional.
 */
 export interface TextWithOptionalCursors {
  /** The document's entire content as a string */
  text: string;
  /**
   * Array of cursor positions within the text. Can be null, undefined, or empty
   * if there are no cursors to track. Each cursor has a unique ID and position.
   */
  cursors: null | undefined | CursorPosition[];
 }
 /**
 * Represents a cursor position within a text document.
 *
 * Cursors are automatically repositioned during text merging to maintain their
 * relative positions as text is inserted, deleted, or modified around them.
 */
 export interface CursorPosition {
  /** Unique identifier for the cursor (can be any number, must be unique within the document) */
  id: number;
  /** Character position in the text, 0-based index from the beginning of the document */
  position: number;
 }
 /**
 * Represents a merged text document with cursor positions and detailed change history.
 *
 * This is the return type of `reconcileWithHistory()` and provides complete information
 * about how the merge was performed, including which parts of the final text came from
 * which source documents.
 */
 export interface TextWithCursorsAndHistory {
  /** The merged document's entire content */
  text: string;
  /**
   * Array of cursor positions within the merged text. Can be empty if there are no cursors to track.
   * All cursors are automatically repositioned from the left and right documents.
   */
  cursors: CursorPosition[];
  /**
   * Detailed provenance information showing the origin of each text span in the result.
   * Each span indicates whether it was unchanged, added from left, added from right, etc.
   */
  history: SpanWithHistory[];
 }
 /**
 * Represents a span of text in the merged result with its change history.
 *
 * This shows exactly which source document contributed each piece of text to the
 * final merged result. Useful for understanding merge decisions and creating
 * visualisations of how documents were combined.
 */
 export interface SpanWithHistory {
  /** The text content of this span */
  text: string;
  /** The origin of this text span in the merge result */
  history: History;
 }
 const UNSUPPORTED_TOKENIZER_ERROR = `Unsupported tokenizer, only ${BUILTIN_TOKENIZERS.join(
  ', '
 )} are supported`;
 let isInitialised = false;
-/**
+const backend: WasmBackend = {
- * Merges three versions of text using intelligent conflict resolution.
+  CursorPosition: wasmCursorPosition,
- *
+  TextWithCursors: wasmTextWithCursors,
- * This is the primary function for 3-way text merging. Unlike traditional merge tools
+  reconcile: wasmReconcile,
- * that produce conflict markers, this function automatically resolves conflicts by
+  reconcileWithHistory: wasmReconcileWithHistory,
- * applying both sets of changes where possible.
+  diff: wasmDiff,
- *
+  undiff: wasmUndiff,
- * @param original - The original/base version of the text that both sides diverged from
+  ensureReady() {
 * @param left - The left version of the text (either string or TextWithCursors with cursor positions)
 * @param right - The right version of the text (either string or TextWithCursors with cursor positions)
 * @param tokenizer - The tokenisation strategy: "Word" (default, recommended for prose),
 *                    "Character" (fine-grained), or "Line" (similar to git merge)
 * @returns The reconciled text with automatically repositioned cursor positions
 *
 * @example
 * ```typescript
 * const original = "Hello world";
 * const left = "Hello beautiful world";    // Added "beautiful"
 * const right = "Hi world";                // Changed "Hello" to "Hi"
 *
 * const result = reconcile(original, left, right);
 * console.log(result.text); // "Hi beautiful world"
 * ```
 */
 export function reconcile(
  original: string,
  left: string | TextWithOptionalCursors,
  right: string | TextWithOptionalCursors,
  tokenizer: BuiltinTokenizer = 'Word'
 ): TextWithCursors {
  init();
  if (!BUILTIN_TOKENIZERS.includes(tokenizer)) {
    throw new Error(UNSUPPORTED_TOKENIZER_ERROR);
  }
  const leftCursor = toWasmTextWithCursors(left);
  const rightCursor = toWasmTextWithCursors(right);
  const result = wasmReconcile(original, leftCursor, rightCursor, tokenizer);
  leftCursor.free();
  rightCursor.free();
  const jsResult = toTextWithCursors(result);
  result.free();
  return jsResult;
 }
 /**
 * Generates a compact diff representation between an original and changed text.
 *
 * These can be parsed and unpacked using the `undiff` function or the Rust crate's EditedText::from_diff.
 * Cursor positions are omitted from the diff result.
 *
 * This function computes the differences between two versions of text and returns
 * a compact representation of those changes.
 *
 * @param original - The original/base version of the text
 * @param changed - The modified version of the text (either string or TextWithCursors with cursor positions)
 * @param tokenizer - The tokenisation strategy, which is the same as used in `reconcile`.
 * @returns An array of inserts (strings), deletes (negative integers), and retained spans (positive integers).
 */
 export function diff(
  original: string,
  changed: string | TextWithOptionalCursors,
  tokenizer: BuiltinTokenizer = 'Word'
 ): Array<number | string> {
  init();
  if (!BUILTIN_TOKENIZERS.includes(tokenizer)) {
    throw new Error(UNSUPPORTED_TOKENIZER_ERROR);
  }
  const changedWasm = toWasmTextWithCursors(changed);
  const result = wasmDiff(original, changedWasm, tokenizer);
  changedWasm.free();
  return result.map((item) => (typeof item === 'bigint' ? Number(item) : item));
 }
 /**
 * Applies a compact diff to an original text to reconstruct the changed version.
 *
 * This function takes an original text and a compact diff representation (as produced
 * by the `diff` function) and reconstructs the modified text.
 *
 * @param original - The original/base version of the text
 * @param diff - The compact diff array (inserts as strings, deletes as negative integers, retained spans as positive integers)
 * @param tokenizer - The tokenisation strategy, which is the same as used in `reconcile`.
 * @returns The reconstructed changed text as a string.
 */
 export function undiff(
  original: string,
  diff: Array<number | bigint | string>,
  tokenizer: BuiltinTokenizer = 'Word'
 ): string {
  init();
  if (!BUILTIN_TOKENIZERS.includes(tokenizer)) {
    throw new Error(UNSUPPORTED_TOKENIZER_ERROR);
  }
  return wasmUndiff(original, diff, tokenizer);
 }
 /**
 * Merges three versions of text and returns detailed provenance information.
 *
 * This function behaves like `reconcile()` but also provides
 * detailed historical information about the origin of each text span in the result.
 * This is valuable for understanding how the merge was performed and which changes
 * came from which source.
 *
 * Note: Computing the history is computationally more expensive than the basic merge.
 *
 * @param original - The original/base version of the text that both sides diverged from
 * @param left - The left version of the text (either string or TextWithCursors with cursor positions)
 * @param right - The right version of the text (either string or TextWithCursors with cursor positions)
 * @param tokenizer - The tokenisation strategy: "Word" (default, recommended for prose),
 *                    "Character" (fine-grained), or "Line" (similar to git merge)
 * @returns The reconciled text with cursor positions and detailed change history
 *
 * @example
 * ```typescript
 * const original = "Hello world";
 * const left = "Hello beautiful world";
 * const right = "Hi world";
 *
 * const result = reconcileWithHistory(original, left, right);
 * console.log(result.text); // "Hi beautiful world"
 * console.log(result.history); // Array of SpanWithHistory objects showing change origins
 * ```
 */
 export function reconcileWithHistory(
  original: string,
  left: string | TextWithOptionalCursors,
  right: string | TextWithOptionalCursors,
  tokenizer: BuiltinTokenizer = 'Word'
 ): TextWithCursorsAndHistory {
  init();
  if (!BUILTIN_TOKENIZERS.includes(tokenizer)) {
    throw new Error(UNSUPPORTED_TOKENIZER_ERROR);
  }
  const leftCursor = toWasmTextWithCursors(left);
  const rightCursor = toWasmTextWithCursors(right);
  const result = wasmReconcileWithHistory(original, leftCursor, rightCursor, tokenizer);
  leftCursor.free();
  rightCursor.free();
  const jsResult = toTextWithCursors(result);
  const history = result.history().map(toSpanWithHistory);
  result.free();
  return {
    ...jsResult,
    history,
  };
 }
 function init() {
    if (isInitialised) {
      return;
    }
@ -305,47 +32,18 @@ function init() {
    initSync({ module: wasmBinary });
    isInitialised = true;
-}
+  },
 function toWasmTextWithCursors(
  text: string | TextWithOptionalCursors
 ): wasmTextWithCursors {
  const isInputString = typeof text === 'string';
  const leftText = isInputString ? text : text.text;
  const leftCursors = isInputString ? [] : (text.cursors ?? []);
  return new wasmTextWithCursors(leftText, leftCursors.map(toWasmCursorPosition));
 }
 function toWasmCursorPosition({ id, position }: CursorPosition): wasmCursorPosition {
  return new wasmCursorPosition(id, position);
 }
 function toTextWithCursors(textWithCursor: wasmTextWithCursors): TextWithCursors {
  const wasmCursors = textWithCursor.cursors();
  const cursors = wasmCursors.map(toCursorPosition);
  for (const cursor of wasmCursors) {
    cursor.free();
  }
  return {
    text: textWithCursor.text(),
    cursors,
 };
 }
-function toCursorPosition(cursor: wasmCursorPosition): CursorPosition {
+export const { reconcile, diff, undiff, reconcileWithHistory } =
-  return {
+  makeReconcileApi(backend);
    id: cursor.id(),
    position: cursor.characterIndex(),
  };
 }
-function toSpanWithHistory(span: wasmSpanWithHistory): SpanWithHistory {
+export type {
-  const result = {
+  BuiltinTokenizer,
-    text: span.text(),
+  History,
-    history: span.history(),
+  CursorPosition,
-  };
+  TextWithCursors,
-  span.free();
+  TextWithOptionalCursors,
-  return result;
+  TextWithCursorsAndHistory,
-}
+  SpanWithHistory,
 } from './core';
--- a/reconcile-js/webpack.config.js
+++ b/reconcile-js/webpack.config.js
@ -2,7 +2,6 @@ const path = require('path');
 const { merge } = require('webpack-merge');
 const common = {
  entry: './src/index.ts',
  optimization: {
    // the consuming project should take care of minification
    minimize: false,
@ -38,8 +37,10 @@ const common = {
 };
 module.exports = [
  // Web build: real WebAssembly, instantiated synchronously from inlined base64.
  merge(common, {
    target: 'web',
    entry: './src/index.ts',
    output: {
      path: path.resolve(__dirname, 'dist'),
      filename: 'reconcile.web.js',
@ -50,12 +51,31 @@ module.exports = [
      globalObject: 'this',
    },
  }),
  // Node build: real WebAssembly.
  merge(common, {
    target: 'node',
    entry: './src/index.ts',
    output: {
      path: path.resolve(__dirname, 'dist'),
      filename: 'reconcile.node.js',
      libraryTarget: 'commonjs2',
    },
  }),
  // React Native build: wasm2js (pure JS), for Hermes which has no
  // `WebAssembly` global. Sources come from `pkg-rn/`
  merge(common, {
    target: 'web',
    entry: './src/index.rn.ts',
    output: {
      path: path.resolve(__dirname, 'dist'),
      filename: 'reconcile.rn.js',
      library: {
        name: 'reconcile',
        type: 'umd',
      },
      globalObject: 'this',
    },
  }),
 ];
--- a/reconcile-python/Cargo.lock
+++ b/reconcile-python/Cargo.lock
@ -2,6 +2,22 @@
 # It is not intended for manual editing.
 version = 4
 [[package]]
 name = "cc"
 version = "1.2.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "556e016178bb5662a08681bbe0f00f8e17631781a4dfc8c45e466e4b185ec27f"
 dependencies = [
 "find-msvc-tools",
 "shlex",
 ]
 [[package]]
 name = "find-msvc-tools"
 version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
 [[package]]
 name = "heck"
 version = "0.5.0"
@ -55,6 +71,7 @@ version = "0.28.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8bf94ee265674bf76c09fa430b0e99c26e319c945d96ca0d5a8215f31bf81cf7"
 dependencies = [
 "python3-dll-a",
 "target-lexicon",
 ]
@ -93,6 +110,15 @@ dependencies = [
 "syn",
 ]
 [[package]]
 name = "python3-dll-a"
 version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d80ba7540edb18890d444c5aa8e1f1f99b1bdf26fb26ae383135325f4a36042b"
 dependencies = [
 "cc",
 ]
 [[package]]
 name = "quote"
 version = "1.0.45"
@ -104,19 +130,25 @@ dependencies = [
 [[package]]
 name = "reconcile-text"
-version = "0.11.0"
+version = "0.12.1"
 dependencies = [
 "thiserror",
 ]
 [[package]]
 name = "reconcile-text-python"
-version = "0.11.0"
+version = "0.12.1"
 dependencies = [
 "pyo3",
 "reconcile-text",
 ]
 [[package]]
 name = "shlex"
 version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8fadd59c855ef2080decdef8ff161eb6661b86933c9d82e5ba29dc602a55aba"
 [[package]]
 name = "syn"
 version = "2.0.117"
--- a/reconcile-python/Cargo.toml
+++ b/reconcile-python/Cargo.toml
@ -1,6 +1,6 @@
 [package]
 name = "reconcile-text-python"
-version = "0.11.0"
+version = "0.12.1"
 edition = "2024"
 rust-version = "1.94"
 authors = ["Andras Schmelczer <andras@schmelczer.dev>"]
@ -13,4 +13,4 @@ crate-type = ["cdylib"]
 [dependencies]
 reconcile-text = { path = ".." }
-pyo3 = { version = "0.28.2", features = ["extension-module"] }
+pyo3 = { version = "0.28.2", features = ["extension-module", "abi3-py39", "generate-import-lib"] }
--- a/reconcile-python/pyproject.toml
+++ b/reconcile-python/pyproject.toml
@ -4,7 +4,7 @@ build-backend = "maturin"
 [project]
 name = "reconcile-text"
-version = "0.11.0"
+version = "0.12.1"
 description = "Intelligent 3-way text merging with automated conflict resolution"
 readme = "README.md"
 license = { text = "MIT" }
--- a/reconcile-python/uv.lock
+++ b/reconcile-python/uv.lock
@ -168,7 +168,7 @@ wheels = [
 [[package]]
 name = "reconcile-text"
-version = "0.11.0"
+version = "0.12.1"
 source = { editable = "." }
 [package.dev-dependencies]
--- a/scripts/lint.sh
+++ b/scripts/lint.sh
@ -5,9 +5,6 @@ set -e
 which cargo-machete || cargo install cargo-machete
 cargo machete
 which lychee || cargo install lychee
 lychee --verbose --exclude npmjs.com README.md
 cargo clippy --all-targets --all-features --fix --allow-dirty --allow-staged
 cargo fmt --all
Author	SHA1	Message	Date
Andras Schmelczer	fcc856279c	Bump versions to 0.12.1 All checks were successful Check / build (push) Successful in 9m31s Details Publish / build (push) Successful in 9m53s Details Publish / publish-crate (push) Has been skipped Details Publish / publish-npm (push) Has been skipped Details Publish / publish-pypi (push) Successful in 6m53s Details	2026-05-31 22:31:39 +01:00
Andras Schmelczer	fd3a374b0f	Fix windows build Some checks failed Publish / publish-crate (push) Blocked by required conditions Details Publish / publish-npm (push) Blocked by required conditions Details Publish / publish-pypi (push) Blocked by required conditions Details Check / build (push) Has been cancelled Details Publish / build (push) Has been cancelled Details	2026-05-31 22:31:18 +01:00
Andras Schmelczer	171045ad66	Bump versions to 0.12.0 Some checks failed Check / build (push) Successful in 8m51s Details Publish / build (push) Successful in 8m16s Details Publish / publish-crate (push) Has been skipped Details Publish / publish-pypi (push) Failing after 3m39s Details Publish / publish-npm (push) Successful in 1m43s Details	2026-05-31 20:28:49 +01:00
Andras Schmelczer	a8fbac6934	Add react-native support (#63 ) Some checks failed Publish / build (push) Waiting to run Details Publish / publish-crate (push) Blocked by required conditions Details Publish / publish-npm (push) Blocked by required conditions Details Publish / publish-pypi (push) Blocked by required conditions Details Check / build (push) Has been cancelled Details Reviewed-on: https://home.schmelczer.dev/git/git/andras/reconcile/pulls/63	2026-05-31 20:28:20 +01:00
Andras Schmelczer	08e7d824f4	Publish All checks were successful Check / build (pull_request) Successful in 9m11s Details Check / build (push) Successful in 7m53s Details Publish / build (push) Successful in 6m31s Details Publish / publish-crate (push) Has been skipped Details Publish / publish-npm (push) Has been skipped Details Publish / publish-pypi (push) Has been skipped Details	2026-05-31 20:08:23 +01:00
Andras Schmelczer	17a96be0fc	Install UV All checks were successful Check / build (pull_request) Successful in 7m58s Details Publish / build (push) Successful in 8m39s Details Publish / publish-crate (push) Has been skipped Details Publish / publish-npm (push) Has been skipped Details Check / build (push) Successful in 9m51s Details	2026-05-22 08:17:19 +01:00
Andras Schmelczer	22723cbcae	Remove Some checks failed Check / build (pull_request) Failing after 1m27s Details	2026-05-22 08:07:36 +01:00
Andras Schmelczer	8e237bc232	Improve TS docs	2026-05-22 08:05:55 +01:00
Andras Schmelczer	c1bc0b8955	Migrate to forgejo Some checks failed Check / build (pull_request) Failing after 2m27s Details	2026-05-21 21:15:22 +01:00