From 5bb420e162b75af34a4262e74e97972ff901676f Mon Sep 17 00:00:00 2001
From: Andras Schmelczer <andras@schmelczer.dev>
Date: Sat, 5 Apr 2025 09:45:44 +0100
Subject: [PATCH] Add diff tests

---
 backend/reconcile/src/diffs/myers.rs          | 54 ++++++++++++++++++
 ...le__diffs__myers__tests__complex_diff.snap | 55 +++++++++++++++++++
 ...ile__diffs__myers__tests__delete_only.snap | 19 +++++++
 ...iffs__myers__tests__identical_content.snap | 23 ++++++++
 ...ile__diffs__myers__tests__insert_only.snap | 19 +++++++
 ...iffs__myers__tests__prefix_and_suffix.snap | 43 +++++++++++++++
 .../reconcile/tests/examples/multiline.yml    | 20 +++++++
 7 files changed, 233 insertions(+)
 create mode 100644 backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__complex_diff.snap
 create mode 100644 backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__delete_only.snap
 create mode 100644 backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__identical_content.snap
 create mode 100644 backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__insert_only.snap
 create mode 100644 backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__prefix_and_suffix.snap
 create mode 100644 backend/reconcile/tests/examples/multiline.yml

diff --git a/backend/reconcile/src/diffs/myers.rs b/backend/reconcile/src/diffs/myers.rs
index 9692c22..da75404 100644
--- a/backend/reconcile/src/diffs/myers.rs
+++ b/backend/reconcile/src/diffs/myers.rs
@@ -282,3 +282,57 @@ fn conquer<T>(
         ));
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use insta::assert_debug_snapshot;
+
+    use super::*;
+
+    #[test]
+    fn test_empty_diff() {
+        let old: Vec<Token<String>> = vec![];
+        let new: Vec<Token<String>> = vec![];
+        let result = diff(&old, &new);
+        assert_eq!(result.len(), 0);
+    }
+
+    #[test]
+    fn test_identical_content() {
+        let content = vec!["a".into(), "b".into(), "c".into()];
+        let result = diff(&content, &content);
+        assert_debug_snapshot!(result);
+    }
+
+    #[test]
+    fn test_insert_only() {
+        let old: Vec<Token<String>> = vec![];
+        let new: Vec<Token<String>> = vec!["a".into(), "b".into()];
+        let result = diff(&old, &new);
+        assert_debug_snapshot!(result);
+    }
+
+    #[test]
+    fn test_delete_only() {
+        let old = vec!["a".into(), "b".into()];
+        let new: Vec<Token<String>> = vec![];
+        let result = diff(&old, &new);
+        assert_debug_snapshot!(result);
+    }
+
+    #[test]
+    fn test_prefix_and_suffix() {
+        let old = vec!["a".into(), "b".into(), "c".into(), "d".into()];
+        let new = vec!["a".into(), "x".into(), "d".into()];
+        let result = diff(&old, &new);
+        assert_debug_snapshot!(result);
+    }
+
+    #[test]
+    fn test_complex_diff() {
+        let old = vec!["a".into(), "b".into(), "c".into(), "d".into()];
+        let new = vec!["a".into(), "x".into(), "c".into(), "y".into()];
+        let result = diff(&old, &new);
+        assert_debug_snapshot!(result);
+    }
+}
diff --git a/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__complex_diff.snap b/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__complex_diff.snap
new file mode 100644
index 0000000..8c89ed3
--- /dev/null
+++ b/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__complex_diff.snap
@@ -0,0 +1,55 @@
+---
+source: reconcile/src/diffs/myers.rs
+expression: result
+snapshot_kind: text
+---
+[
+    Equal(
+        [
+            Token {
+                normalised: "a",
+                original: "a",
+            },
+        ],
+    ),
+    Insert(
+        [
+            Token {
+                normalised: "x",
+                original: "x",
+            },
+        ],
+    ),
+    Delete(
+        [
+            Token {
+                normalised: "b",
+                original: "b",
+            },
+        ],
+    ),
+    Equal(
+        [
+            Token {
+                normalised: "c",
+                original: "c",
+            },
+        ],
+    ),
+    Insert(
+        [
+            Token {
+                normalised: "y",
+                original: "y",
+            },
+        ],
+    ),
+    Delete(
+        [
+            Token {
+                normalised: "d",
+                original: "d",
+            },
+        ],
+    ),
+]
diff --git a/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__delete_only.snap b/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__delete_only.snap
new file mode 100644
index 0000000..f07eb3d
--- /dev/null
+++ b/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__delete_only.snap
@@ -0,0 +1,19 @@
+---
+source: reconcile/src/diffs/myers.rs
+expression: result
+snapshot_kind: text
+---
+[
+    Delete(
+        [
+            Token {
+                normalised: "a",
+                original: "a",
+            },
+            Token {
+                normalised: "b",
+                original: "b",
+            },
+        ],
+    ),
+]
diff --git a/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__identical_content.snap b/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__identical_content.snap
new file mode 100644
index 0000000..a99e276
--- /dev/null
+++ b/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__identical_content.snap
@@ -0,0 +1,23 @@
+---
+source: reconcile/src/diffs/myers.rs
+expression: result
+snapshot_kind: text
+---
+[
+    Equal(
+        [
+            Token {
+                normalised: "a",
+                original: "a",
+            },
+            Token {
+                normalised: "b",
+                original: "b",
+            },
+            Token {
+                normalised: "c",
+                original: "c",
+            },
+        ],
+    ),
+]
diff --git a/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__insert_only.snap b/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__insert_only.snap
new file mode 100644
index 0000000..b32c8ce
--- /dev/null
+++ b/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__insert_only.snap
@@ -0,0 +1,19 @@
+---
+source: reconcile/src/diffs/myers.rs
+expression: result
+snapshot_kind: text
+---
+[
+    Insert(
+        [
+            Token {
+                normalised: "a",
+                original: "a",
+            },
+            Token {
+                normalised: "b",
+                original: "b",
+            },
+        ],
+    ),
+]
diff --git a/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__prefix_and_suffix.snap b/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__prefix_and_suffix.snap
new file mode 100644
index 0000000..03c8fee
--- /dev/null
+++ b/backend/reconcile/src/diffs/snapshots/reconcile__diffs__myers__tests__prefix_and_suffix.snap
@@ -0,0 +1,43 @@
+---
+source: reconcile/src/diffs/myers.rs
+expression: result
+snapshot_kind: text
+---
+[
+    Equal(
+        [
+            Token {
+                normalised: "a",
+                original: "a",
+            },
+        ],
+    ),
+    Delete(
+        [
+            Token {
+                normalised: "b",
+                original: "b",
+            },
+            Token {
+                normalised: "c",
+                original: "c",
+            },
+        ],
+    ),
+    Insert(
+        [
+            Token {
+                normalised: "x",
+                original: "x",
+            },
+        ],
+    ),
+    Equal(
+        [
+            Token {
+                normalised: "d",
+                original: "d",
+            },
+        ],
+    ),
+]
diff --git a/backend/reconcile/tests/examples/multiline.yml b/backend/reconcile/tests/examples/multiline.yml
new file mode 100644
index 0000000..c751feb
--- /dev/null
+++ b/backend/reconcile/tests/examples/multiline.yml
@@ -0,0 +1,20 @@
+parent: Hello!
+left: |
+  Hello there!
+
+  How are you?
+
+right: |
+  Hello there!
+
+
+  Best,
+  Andras
+
+expected: |
+  Hello there!
+
+  How are you?
+
+  Best,
+  Andras