Preserve exact hunks across renames

CHANGELOG.md

@@ -6,6 +6,7 @@ All notable changes are documented here. This project follows Semantic Versionin
 
 ### Fixed
 
+- Preserved precise changed-line hunks across renames by scoping per-file Git diffs to both the previous and current path. This prevents a rename with content edits from being reinterpreted as a whole-file addition and overstating changed-line or call-reference evidence.
 - Preserved trailing whitespace in Git repository-root paths. `findRepository()` now removes only Git's record line terminator instead of applying JavaScript `String.trim()`, preventing a repository such as `repository ` from being silently redirected to a sibling path with the trimmed spelling.
 - Tightened Python test-runner exit-code 5 handling. Pytest and the stdlib `unittest` CLI use code 5 for no-test outcomes, but repository-local modules can also terminate runner imports with code 5 before trustworthy lifecycle observation. ProofDiff now accepts exit 5 as non-failing only when high-confidence exact zero-test observer data corroborates it: directly for targeted pytest, or through the paired targeted observer for opaque pytest/unittest commands. Uncorroborated exit-5 failures remain verification failures.
 - Preserved LCOV `SF:` source paths exactly instead of applying JavaScript-style whitespace trimming. Leading or trailing spaces and Unicode whitespace are valid path characters, so silently erasing them could alias artifact coverage for one path onto a different changed repository file and overstate changed-line evidence.

src/git.ts

@@ -271,7 +271,8 @@ export async function changedFiles(root: string, diffArgs: string[], includeUntr
       metric = { additions: lines, deletions: 0, binary };
       patch = content === null ? "" : `@@ -0,0 +1,${lines} @@\n${content.split("\n").map((line) => `+${line}`).join("\n")}`;
     } else {
-      patch = await git(root, ["diff", ...safeDiffOptions, "--unified=0", "--find-renames", ...diffArgs, "--", entry.path], true);
+      const pathspec = entry.previousPath === undefined ? [entry.path] : [entry.previousPath, entry.path];
+      patch = await git(root, ["diff", ...safeDiffOptions, "--unified=0", "--find-renames", ...diffArgs, "--", ...pathspec], true);
     }
     files.push({
       path: entry.path,

tests/git.test.ts

@@ -70,6 +70,49 @@ test("rename metadata preserves both paths", async (context) => {
   assert.equal(file?.change, "renamed");
   assert.equal(file?.previousPath, "src/old name.ts");
   assert.equal(file?.path, "src/new name.ts");
+  assert.deepEqual(file?.hunks, []);
+});
+
+test("rename with content modification preserves the minimal changed hunk", async (context) => {
+  const root = await initializeRepository({
+    "src/foo.js": [
+      "export function helperA() { return 1; }",
+      "",
+      "export function target() {",
+      "  helperA();",
+      "  const x = 1;",
+      "  const y = 2;",
+      "  return x + y;",
+      "}",
+      "",
+    ].join("\n"),
+  });
+  context.after(() => rm(root, { recursive: true, force: true }));
+  git(root, "mv", "src/foo.js", "src/bar.js");
+  await writeFiles(root, {
+    "src/bar.js": [
+      "export function helperA() { return 1; }",
+      "",
+      "export function target() {",
+      "  helperA();",
+      "  const x = 1;",
+      "  const y = 3;",
+      "  return x + y;",
+      "}",
+      "",
+    ].join("\n"),
+  });
+  const { args } = await selectDiff(root, {});
+  const [file] = await changedFiles(root, args, true);
+  assert.equal(file?.change, "renamed");
+  assert.equal(file?.previousPath, "src/foo.js");
+  assert.equal(file?.path, "src/bar.js");
+  assert.equal(file?.additions, 1);
+  assert.equal(file?.deletions, 1);
+  assert.deepEqual(file?.hunks, [{
+    oldRange: { start: 6, end: 6 },
+    newRange: { start: 6, end: 6 },
+  }]);
 });
 
 test("staged selection excludes later unstaged edits", async (context) => {