Add mergeTextWithHistory function

examples/website/index.html

@@ -29,26 +29,53 @@
         </header>
 
         <main>
-            <div class="text-area diamond-parent">
+            <div class="text-area-card diamond-parent">
                 <label for="original">Original</label>
                 <textarea id="original" name="original"></textarea>
             </div>
 
-            <div class="text-area diamond-left">
+            <div class="text-area-card diamond-left">
-                <label for="left">First concurrent edit</label>
+                <label for="left">
+                    First concurrent edit
+                    <div class="box Left"></div>
+                </label>
                 <textarea id="left" name="left"></textarea>
             </div>
 
-            <div class="text-area diamond-right">
+            <div class="text-area-card diamond-right">
-                <label for="right">Second concurrent edit</label>
+                <label for="right"
+                    >Second concurrent edit
+                    <div
+                        class="box Right"
+                        title="Indicates changes from the second concurrent edit"
+                    ></div>
+                </label>
                 <textarea id="right" name="right"></textarea>
             </div>
 
-            <button id="merge-button" type="button">Merge</button>
+            <div class="text-area-card diamond-result">
-
+                <label
-            <div class="text-area diamond-result">
+                    ><svg
-                <label for="merged">Deconflicted result (readonly)</label>
+                        xmlns="http://www.w3.org/2000/svg"
-                <textarea id="merged" name="merged" readonly></textarea>
+                        width="24"
+                        height="24"
+                        viewBox="0 0 24 24"
+                        fill="none"
+                        stroke="currentColor"
+                        stroke-width="2"
+                        stroke-linecap="round"
+                        stroke-linejoin="round"
+                    >
+                        <path stroke="none" d="M0 0h24v24H0z" fill="none" />
+                        <path
+                            d="M10 10l-6 6v4h4l6 -6m1.99 -1.99l2.504 -2.504a2.828 2.828 0 1 0 -4 -4l-2.5 2.5"
+                        />
+                        <path d="M13.5 6.5l4 4" />
+                        <path d="M3 3l18 18" />
+                    </svg>
+                    Deconflicted result (readonly)</label
+                >
+                <div id="merged"></div>
             </div>
         </main>
 
@@ -64,9 +91,15 @@
                     width="24"
                     height="24"
                     viewBox="0 0 24 24"
+                    fill="none"
+                    stroke="currentColor"
+                    stroke-width="2"
+                    stroke-linecap="round"
+                    stroke-linejoin="round"
                 >
+                    <path stroke="none" d="M0 0h24v24H0z" fill="none" />
                     <path
-                        d="M12 0c-6.626 0-12 5.373-12 12 0 5.302 3.438 9.8 8.207 11.387.599.111.793-.261.793-.577v-2.234c-3.338.726-4.033-1.416-4.033-1.416-.546-1.387-1.333-1.756-1.333-1.756-1.089-.745.083-.729.083-.729 1.205.084 1.839 1.237 1.839 1.237 1.07 1.834 2.807 1.304 3.492.997.107-.775.418-1.305.762-1.604-2.665-.305-5.467-1.334-5.467-5.931 0-1.311.469-2.381 1.236-3.221-.124-.303-.535-1.524.117-3.176 0 0 1.008-.322 3.301 1.23.957-.266 1.983-.399 3.003-.404 1.02.005 2.047.138 3.006.404 2.291-1.552 3.297-1.23 3.297-1.23.653 1.653.242 2.874.118 3.176.77.84 1.235 1.911 1.235 3.221 0 4.609-2.807 5.624-5.479 5.921.43.372.823 1.102.823 2.222v3.293c0 .319.192.694.801.576 4.765-1.589 8.199-6.086 8.199-11.386 0-6.627-5.373-12-12-12z"
+                        d="M9 19c-4.3 1.4 -4.3 -2.5 -6 -3m12 5v-3.5c0 -1 .1 -1.4 -.5 -2c2.8 -.3 5.5 -1.4 5.5 -6a4.6 4.6 0 0 0 -1.3 -3.2a4.2 4.2 0 0 0 -.1 -3.2s-1.1 -.3 -3.5 1.3a12.3 12.3 0 0 0 -6.2 0c-2.4 -1.6 -3.5 -1.3 -3.5 -1.3a4.2 4.2 0 0 0 -.1 3.2a4.6 4.6 0 0 0 -1.3 3.2c0 4.6 2.7 5.7 5.5 6c-.6 .6 -.6 1.2 -.5 2v3.5"
                     />
                 </svg>
             </a>

examples/website/script.js

@@ -1,10 +1,9 @@
-import init, { mergeText } from "./reconcile.js";
+import init, { mergeText, mergeTextWithHistory } from "./reconcile.js";
 
 const originalTextArea = document.getElementById("original");
 const leftTextArea = document.getElementById("left");
 const rightTextArea = document.getElementById("right");
 const mergedTextArea = document.getElementById("merged");
-const mergeButton = document.getElementById("merge-button");
 
 const sampleTexts = [
     "The quick brown fox jumps over the lazy dog.",
@@ -17,16 +16,35 @@ const sampleTexts = [
 async function run() {
     await init();
 
-    mergeButton.addEventListener("click", () => {
+    originalTextArea.addEventListener("input", updateMergedText);
-        const original = originalTextArea.value;
+    leftTextArea.addEventListener("input", updateMergedText);
-        const left = leftTextArea.value;
+    rightTextArea.addEventListener("input", updateMergedText);
-        const right = rightTextArea.value;
-
-        const result = mergeText(original, left, right);
-        mergedTextArea.value = result;
-    });
 
     loadSample();
+    updateMergedText();
+
+    // Put cursor at the end of the text in leftTextArea
+    leftTextArea.focus();
+    leftTextArea.selectionStart = leftTextArea.value.length;
+    leftTextArea.selectionEnd = leftTextArea.value.length;
+}
+
+function updateMergedText() {
+    const original = originalTextArea.value;
+    const left = leftTextArea.value;
+    const right = rightTextArea.value;
+
+    const results = mergeTextWithHistory(original, left, right);
+
+    mergedTextArea.innerHTML = "";
+
+    for (const result of results) {
+        const span = document.createElement("span");
+        span.className = result.history();
+        span.textContent = result.text();
+        mergedTextArea.appendChild(span);
+        result.free();
+    }
 }
 
 function loadSample() {
@@ -35,7 +53,6 @@ function loadSample() {
     originalTextArea.value = text;
     leftTextArea.value = text;
     rightTextArea.value = text;
-    mergedTextArea.value = "";
 }
 
 run();

examples/website/style.css

@@ -1,6 +1,7 @@
 * {
     box-sizing: border-box;
     margin: 0;
+    user-select: none;
 }
 
 html,
@@ -40,7 +41,7 @@ main {
     flex: 1;
     display: grid;
     grid-template-rows: auto auto auto;
-    grid-template-columns: 1fr auto 1fr;
+    grid-template-columns: 1fr 1fr;
     gap: 20px;
     justify-items: center;
     align-items: center;
@@ -58,34 +59,8 @@ main {
 }
 
 .diamond-right {
-    grid-column: 3;
-    grid-row: 2;
-}
-
-#merge-button {
     grid-column: 2;
     grid-row: 2;
-    padding: 12px 36px;
-    border: none;
-    border-radius: 8px;
-    background: linear-gradient(90deg, #2451a6 0%, #3486eb 100%);
-    color: #fff;
-    font-size: 1.15rem;
-    font-weight: 600;
-    box-shadow: 0 2px 12px 0 rgba(36, 81, 166, 0.08);
-    cursor: pointer;
-    align-self: center;
-    transition: transform 0.2s;
-    margin: 0 32px;
-}
-
-#merge-button:hover {
-    transform: scale(1.1);
-}
-
-.diamond-right {
-    grid-column: 3;
-    grid-row: 2;
 }
 
 .diamond-result {
@@ -93,10 +68,9 @@ main {
     grid-row: 3;
     display: flex;
     align-items: center;
-    pointer-events: none;
 }
 
-.text-area {
+.text-area-card {
     display: flex;
     flex-direction: column;
     align-items: center;
@@ -115,6 +89,15 @@ label {
     color: #2451a6;
 }
 
+.box {
+    width: 1ch;
+    height: 1ch;
+    border-radius: 50%;
+    margin-left: 6px;
+    display: inline-block;
+    transform: scale(1.5);
+}
+
 textarea {
     width: 100%;
     border: none;
@@ -128,6 +111,29 @@ textarea {
     height: 100%;
 }
 
+#merged {
+    width: 100%;
+    text-align: left;
+    user-select: text;
+}
+
+.Left,
+.AddedFromLeft,
+.RemovedFromLeft {
+    background: #12d197;
+}
+
+.Right,
+.AddedFromRight,
+.RemovedFromRight {
+    background: #8575ed;
+}
+
+.RemovedFromLeft,
+.RemovedFromRight {
+    text-decoration: line-through;
+}
+
 @media (max-width: 900px) {
     main {
         padding: 24px 2vw;
@@ -139,29 +145,25 @@ textarea {
         grid-template-columns: 1fr;
         grid-template-rows: auto auto auto auto auto;
     }
+
+    main > * {
+        grid-column: 1;
+    }
+
     .diamond-parent {
         grid-row: 1;
-        grid-column: 1;
     }
 
     .diamond-left {
         grid-row: 2;
-        grid-column: 1;
     }
 
     .diamond-right {
         grid-row: 3;
-        grid-column: 1;
-    }
-
-    #merge-button {
-        grid-row: 4;
-        grid-column: 1;
     }
 
     .diamond-result {
         grid-row: 5;
-        grid-column: 1;
     }
 }
 
@@ -178,6 +180,7 @@ footer {
 
 .github-link > svg {
     position: absolute;
+    color: #5a6272;
     top: 50%;
     right: 36px;
     transform: translateY(-50%);

scripts/dev-website.sh

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -e
+
 rm -rf pkg
 
 wasm-pack build --target web --features wasm

src/lib.rs

@@ -1,3 +1,5 @@
+#![feature(stmt_expr_attributes)]
+
 mod diffs;
 mod operation_transformation;
 mod tokenizer;
@@ -5,9 +7,10 @@ mod utils;
 
 pub use operation_transformation::{
     CursorPosition, EditedText, TextWithCursors, reconcile, reconcile_with_cursors,
-    reconcile_with_tokenizer,
+    reconcile_with_history, reconcile_with_tokenizer,
 };
 pub use tokenizer::{Tokenizer, token::Token, word_tokenizer::word_tokenizer};
+pub use utils::{history::History, side::Side};
 
 #[cfg(feature = "wasm")]
 pub mod wasm;

src/operation_transformation.rs

@@ -7,7 +7,10 @@ pub use cursor::{CursorPosition, TextWithCursors};
 pub use edited_text::EditedText;
 pub use operation::Operation;
 
-use crate::Tokenizer;
+use crate::{
+    Tokenizer,
+    utils::{history::History, side::Side},
+};
 
 #[must_use]
 pub fn reconcile(original: &str, left: &str, right: &str) -> String {
@@ -16,14 +19,22 @@ pub fn reconcile(original: &str, left: &str, right: &str) -> String {
         .to_string()
 }
 
+#[must_use]
+pub fn reconcile_with_history(original: &str, left: &str, right: &str) -> Vec<(History, String)> {
+    let left_operations = EditedText::from_strings(original, left.into(), Side::Left);
+    let right_operations = EditedText::from_strings(original, right.into(), Side::Right);
+
+    left_operations.merge(right_operations).apply_with_history()
+}
+
 #[must_use]
 pub fn reconcile_with_cursors<'a>(
     original: &'a str,
     left: TextWithCursors<'a>,
     right: TextWithCursors<'a>,
 ) -> TextWithCursors<'static> {
-    let left_operations = EditedText::from_strings(original, left);
+    let left_operations = EditedText::from_strings(original, left, Side::Left);
-    let right_operations = EditedText::from_strings(original, right);
+    let right_operations = EditedText::from_strings(original, right, Side::Right);
 
     let merged_operations = left_operations.merge(right_operations);
 
@@ -40,8 +51,10 @@ pub fn reconcile_with_tokenizer<'a, F, T>(
 where
     T: PartialEq + Clone + std::fmt::Debug,
 {
-    let left_operations = EditedText::from_strings_with_tokenizer(original, left, tokenizer);
+    let left_operations =
-    let right_operations = EditedText::from_strings_with_tokenizer(original, right, tokenizer);
+        EditedText::from_strings_with_tokenizer(original, left, tokenizer, Side::Left);
+    let right_operations =
+        EditedText::from_strings_with_tokenizer(original, right, tokenizer, Side::Right);
 
     let merged_operations = left_operations.merge(right_operations);
 

src/operation_transformation/edited_text.rs

@@ -8,7 +8,7 @@ use crate::{
         cook_operations::cook_operations, elongate_operations::elongate_operations,
     },
     tokenizer::{Tokenizer, word_tokenizer::word_tokenizer},
-    utils::{side::Side, string_builder::StringBuilder},
+    utils::{history::History, side::Side, string_builder::StringBuilder},
 };
 
 /// A text document and a sequence of operations that can be applied to the text
@@ -42,8 +42,8 @@ impl<'a> EditedText<'a, String> {
     /// word tokenizer is used to tokenize the text which splits the text on
     /// whitespaces.
     #[must_use]
-    pub fn from_strings(original: &'a str, updated: TextWithCursors<'a>) -> Self {
+    pub fn from_strings(original: &'a str, updated: TextWithCursors<'a>, side: Side) -> Self {
-        Self::from_strings_with_tokenizer(original, updated, &word_tokenizer)
+        Self::from_strings_with_tokenizer(original, updated, &word_tokenizer, side)
     }
 }
 
@@ -60,6 +60,7 @@ where
         original: &'a str,
         updated: TextWithCursors<'a>,
         tokenizer: &Tokenizer<T>,
+        side: Side,
     ) -> Self {
         let original_tokens = (tokenizer)(original);
         let updated_tokens = (tokenizer)(&updated.text);
@@ -68,7 +69,7 @@ where
 
         Self::new(
             original,
-            cook_operations(elongate_operations(diff)).collect(),
+            cook_operations(elongate_operations(diff), side).collect(),
             updated.cursors,
         )
     }
@@ -223,6 +224,39 @@ where
 
         builder.build()
     }
+
+    #[must_use]
+    pub fn apply_with_history(&self) -> Vec<(History, String)> {
+        let mut builder: StringBuilder<'_> = StringBuilder::new(self.text);
+
+        let mut history = Vec::with_capacity(self.operations.len());
+
+        for operation in &self.operations {
+            builder = operation.apply(builder);
+
+            match operation {
+                Operation::Equal { .. } => history.push((History::Unchanged, builder.take())),
+                Operation::Insert { side, .. } => match side {
+                    Side::Left => history.push((History::AddedFromLeft, builder.take())),
+                    Side::Right => history.push((History::AddedFromRight, builder.take())),
+                },
+                Operation::Delete {
+                    deleted_character_count,
+                    order,
+                    side,
+                    ..
+                } => {
+                    let deleted = self.text[*order..*order + *deleted_character_count].to_string();
+                    match side {
+                        Side::Left => history.push((History::RemovedFromLeft, deleted)),
+                        Side::Right => history.push((History::RemovedFromRight, deleted)),
+                    }
+                }
+            }
+        }
+
+        history
+    }
 }
 
 #[cfg(test)]
@@ -237,7 +271,7 @@ mod tests {
         let left = "hello world! How are you?  Adam";
         let right = "Hello, my friend! How are you doing? Albert";
 
-        let operations = EditedText::from_strings(left, right.into());
+        let operations = EditedText::from_strings(left, right.into(), Side::Right);
 
         insta::assert_debug_snapshot!(operations);
 
@@ -249,7 +283,7 @@ mod tests {
     fn test_calculate_operations_with_no_diff() {
         let text = "hello world!";
 
-        let operations = EditedText::from_strings(text, text.into());
+        let operations = EditedText::from_strings(text, text.into(), Side::Right);
 
         assert_debug_snapshot!(operations);
 
@@ -264,8 +298,8 @@ mod tests {
         let right = "Hello world! How are you?";
         let expected = "Hello world! How are you? I'm Andras.";
 
-        let operations_1 = EditedText::from_strings(original, left.into());
+        let operations_1 = EditedText::from_strings(original, left.into(), Side::Left);
-        let operations_2 = EditedText::from_strings(original, right.into());
+        let operations_2 = EditedText::from_strings(original, right.into(), Side::Right);
 
         let operations = operations_1.merge(operations_2);
         assert_eq!(operations.apply(), expected);

src/operation_transformation/operation.rs

@@ -6,7 +6,7 @@ use serde::{Deserialize, Serialize};
 use crate::{
     Token,
     utils::{
-        find_longest_prefix_contained_within::find_longest_prefix_contained_within,
+        find_longest_prefix_contained_within::find_longest_prefix_contained_within, side::Side,
         string_builder::StringBuilder,
     },
 };
@@ -27,11 +27,15 @@ where
     },
 
     Insert {
+        side: Side,
+
         order: usize,
         text: Vec<Token<T>>,
     },
 
     Delete {
+        side: Side,
+
         order: usize,
         deleted_character_count: usize,
 
@@ -68,14 +72,15 @@ where
     }
 
     /// Creates an insert operation with the given index and text.
-    pub fn create_insert(order: usize, text: Vec<Token<T>>) -> Self {
+    pub fn create_insert(order: usize, text: Vec<Token<T>>, side: Side) -> Self {
-        Operation::Insert { order, text }
+        Operation::Insert { side, order, text }
     }
 
     /// Creates a delete operation with the given index and number of
     /// to-be-deleted characters.
-    pub fn create_delete(order: usize, deleted_character_count: usize) -> Self {
+    pub fn create_delete(order: usize, deleted_character_count: usize, side: Side) -> Self {
         Operation::Delete {
+            side,
             order,
             deleted_character_count,
 
@@ -84,8 +89,9 @@ where
         }
     }
 
-    pub fn create_delete_with_text(order: usize, text: String) -> Self {
+    pub fn create_delete_with_text(order: usize, text: String, side: Side) -> Self {
         Operation::Delete {
+            side,
             order,
             deleted_character_count: text.chars().count(),
 
@@ -200,7 +206,7 @@ where
 
         match (operation, previous_operation) {
             (
-                Operation::Insert { order, text },
+                Operation::Insert { side, order, text },
                 Some(Operation::Insert {
                     text: previous_inserted_text,
                     ..
@@ -212,11 +218,12 @@ where
                 let offset_in_tokens =
                     find_longest_prefix_contained_within(previous_inserted_text, &text);
 
-                Operation::create_insert(order, text[offset_in_tokens..].to_vec())
+                Operation::create_insert(order, text[offset_in_tokens..].to_vec(), side)
             }
 
             (
                 Operation::Delete {
+                    side,
                     order,
                     deleted_character_count,
 
@@ -240,19 +247,20 @@ where
 
                 #[cfg(debug_assertions)]
                 let updated_delete = deleted_text.as_ref().map_or_else(
-                    || Operation::create_delete(order + overlap, new_length),
+                    || Operation::create_delete(order + overlap, new_length, side),
                     |text| {
                         Operation::create_delete_with_text(
                             order + overlap,
                             text.chars()
                                 .skip(deleted_character_count - new_length)
                                 .collect::<String>(),
+                            side,
                         )
                     },
                 );
 
                 #[cfg(not(debug_assertions))]
-                let updated_delete = Operation::create_delete(order + overlap, new_length);
+                let updated_delete = Operation::create_delete(order + overlap, new_length, side);
 
                 updated_delete
             }
@@ -334,6 +342,7 @@ where
 
                 #[cfg(debug_assertions)]
                 text,
+                ..
             } => {
                 #[cfg(debug_assertions)]
                 write!(
@@ -349,7 +358,7 @@ where
 
                 Ok(())
             }
-            Operation::Insert { order, text } => {
+            Operation::Insert { order, text, .. } => {
                 write!(
                     f,
                     "<insert '{}' at {order}>",
@@ -365,6 +374,7 @@ where
 
                 #[cfg(debug_assertions)]
                 deleted_text,
+                ..
             } => {
                 #[cfg(debug_assertions)]
                 write!(
@@ -404,7 +414,8 @@ mod tests {
     #[test]
     fn test_apply_delete_with_create() {
         let builder = StringBuilder::new("hello world");
-        let delete_operation = Operation::<()>::create_delete_with_text(0, "hello ".to_owned());
+        let delete_operation =
+            Operation::<()>::create_delete_with_text(0, "hello ".to_owned(), Side::Left);
         let retain_operation = Operation::<()>::create_equal(6, 5);
 
         let mut builder = delete_operation.apply(builder);
@@ -418,7 +429,7 @@ mod tests {
         let builder = StringBuilder::new("hello");
 
         let retain_operation = Operation::<()>::create_equal(0, 5);
-        let insert_operation = Operation::create_insert(5, vec![" my friend".into()]);
+        let insert_operation = Operation::create_insert(5, vec![" my friend".into()], Side::Right);
 
         let mut builder = retain_operation.apply(builder);
         builder = insert_operation.apply(builder);

src/operation_transformation/utils/cook_operations.rs

@@ -1,8 +1,10 @@
-use crate::{diffs::raw_operation::RawOperation, operation_transformation::Operation};
+use crate::{
+    diffs::raw_operation::RawOperation, operation_transformation::Operation, utils::side::Side,
+};
 
 /// Turn raw operations into ordered operations while keeping track of the
 /// original token's indexes.
-pub fn cook_operations<I, T>(raw_operations: I) -> impl Iterator<Item = Operation<T>>
+pub fn cook_operations<I, T>(raw_operations: I, side: Side) -> impl Iterator<Item = Operation<T>>
 where
     I: IntoIterator<Item = RawOperation<T>>,
     T: PartialEq + Clone + std::fmt::Debug,
@@ -27,15 +29,18 @@ where
 
                 op
             }
-            RawOperation::Insert(tokens) => Operation::create_insert(original_text_index, tokens),
+            RawOperation::Insert(tokens) => {
+                Operation::create_insert(original_text_index, tokens, side)
+            }
             RawOperation::Delete(..) => {
                 let op = if cfg!(debug_assertions) {
                     Operation::create_delete_with_text(
                         original_text_index,
                         raw_operation.get_original_text(),
+                        side,
                     )
                 } else {
-                    Operation::create_delete(original_text_index, length)
+                    Operation::create_delete(original_text_index, length, side)
                 };
 
                 original_text_index += length;

src/utils.rs

@@ -1,5 +1,6 @@
 pub mod common_prefix_len;
 pub mod common_suffix_len;
 pub mod find_longest_prefix_contained_within;
+pub mod history;
 pub mod side;
 pub mod string_builder;

src/utils/history.rs

@@ -0,0 +1,15 @@
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+#[cfg(feature = "wasm")]
+use wasm_bindgen::prelude::*;
+
+#[cfg_attr(feature = "wasm", wasm_bindgen)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum History {
+    Unchanged = "Unchanged",
+    AddedFromLeft = "AddedFromLeft",
+    AddedFromRight = "AddedFromRight",
+    RemovedFromLeft = "RemovedFromLeft",
+    RemovedFromRight = "RemovedFromRight",
+}

src/utils/side.rs

@@ -1,5 +1,9 @@
 use std::fmt::Display;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum Side {
     Left,

src/utils/string_builder.rs

@@ -35,7 +35,8 @@ impl StringBuilder<'_> {
 
         self.original.nth(length - 1);
 
-        if cfg!(debug_assertions) {
+        #[cfg(debug_assertions)]
+        {
             self.remaining = self.remaining.chars().skip(length).collect();
         }
     }
@@ -44,20 +45,28 @@ impl StringBuilder<'_> {
     pub fn retain(&mut self, length: usize) {
         self.buffer.extend(self.original.by_ref().take(length));
 
-        if cfg!(debug_assertions) {
+        #[cfg(debug_assertions)]
+        {
             self.remaining = self.remaining.chars().skip(length).collect();
         }
     }
 
+    /// Returns the currently built buffer and clears it.
+    pub fn take(&mut self) -> String {
+        let result = self.buffer.clone();
+        self.buffer.clear();
+        result
+    }
+
     /// Finish building the string after copying the remaining original string
     /// since the last insertion or deletion.
     pub fn build(self) -> String { self.buffer }
 
-    #[cfg(debug_assertions)]
     /// Get a slice of the remaining original string. The slice starts from
     /// where the next delete/retain operation would start and is of length
     /// `length`. The implementation is quite suboptimal but it's only used
     /// for debugging.
+    #[cfg(debug_assertions)]
     pub fn get_slice_from_remaining(&self, length: usize) -> String {
         let result = self.remaining.chars().take(length).collect::<String>();
 

src/wasm.rs

@@ -1,2 +1,2 @@
-pub mod cursor;
 pub mod lib;
+pub mod types;

src/wasm/lib.rs

@@ -13,7 +13,7 @@ use core::str;
 
 use wasm_bindgen::prelude::*;
 
-use crate::wasm::cursor::JsTextWithCursors;
+use crate::wasm::types::{JsTextWithCursors, JsTextWithHistory};
 
 /// Merge two documents with a common parent. Relies on `reconcile::reconcile`
 /// for texts and returns the right document as-is if either of the updated
@@ -58,6 +58,18 @@ pub fn merge_text(parent: &str, left: &str, right: &str) -> String {
     crate::reconcile(parent, left, right)
 }
 
+/// WASM wrapper around `crate::reconcile` for merging text.
+#[wasm_bindgen(js_name = mergeTextWithHistory)]
+#[must_use]
+pub fn merge_text_with_history(parent: &str, left: &str, right: &str) -> Vec<JsTextWithHistory> {
+    set_panic_hook();
+
+    crate::reconcile_with_history(parent, left, right)
+        .into_iter()
+        .map(Into::into)
+        .collect()
+}
+
 /// WASM wrapper around `reconcile::reconcile_with_cursors` for merging text.
 #[wasm_bindgen(js_name = mergeTextWithCursors)]
 #[must_use]

src/wasm/types.rs

@@ -1,5 +1,7 @@
 use wasm_bindgen::prelude::*;
 
+use crate::History;
+
 /// Wrapper type to expose `TextWithCursors` to JS.
 #[wasm_bindgen]
 #[derive(Debug, Clone, PartialEq)]
@@ -86,3 +88,24 @@ impl From<crate::CursorPosition> for JsCursorPosition {
         }
     }
 }
+
+/// Wrapper type to expose `(History, String)` to JS.
+#[wasm_bindgen]
+#[derive(Debug, Clone, PartialEq)]
+pub struct JsTextWithHistory {
+    history: History,
+    text: String,
+}
+
+impl From<(History, String)> for JsTextWithHistory {
+    fn from((history, text): (History, String)) -> Self { JsTextWithHistory { history, text } }
+}
+
+#[wasm_bindgen]
+impl JsTextWithHistory {
+    #[must_use]
+    pub fn history(&self) -> History { self.history }
+
+    #[must_use]
+    pub fn text(&self) -> String { self.text.clone() }
+}

tests/examples/deletes.yml

@@ -25,10 +25,10 @@ right: long with big and small
 expected: long small
 
 ---
-parent: long run of text where one barely has no changes but has cursors
+parent: long run of text where one barely has changes but has cursors
-left: long| run of tex|t where one barely has no |changes but has |cursors
+left: long| run of tex|t where one barely has |changes but has |cursors
-right: long run one barely has no changes cursors
+right: long run one barely has changes cursors
-expected: long| ru|n one barely has no |changes |cursors
+expected: long| ru|n one barely has |changes |cursors
 
 ---
 parent: long text where the cursor has to be clamped after delete

tests/web.rs

@@ -1,8 +1,8 @@
 #![cfg(feature = "wasm")]
 
 use reconcile::wasm::{
-    cursor::{JsCursorPosition, JsTextWithCursors},
     lib::{is_binary, is_file_type_mergable, merge, merge_text, merge_text_with_cursors},
+    types::{JsCursorPosition, JsTextWithCursors},
 };
 use wasm_bindgen_test::*;