fix: handle deleted empty files

Author: yeonjuan

src/__fixtures__/deleted-empty-file

@@ -0,0 +1,3 @@
+diff --git a/src/empty b/src/empty
+deleted file mode 100644
+index e69de29..0000000

src/__tests__/__snapshots__/deleted-empty-file.test.ts.snap

@@ -0,0 +1,14 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`deleted-empty-file parse \`deleted-empty-file\` 1`] = `
+{
+  "files": [
+    {
+      "chunks": [],
+      "path": "src/empty",
+      "type": "DeletedFile",
+    },
+  ],
+  "type": "GitDiff",
+}
+`;

src/__tests__/deleted-empty-file.test.ts

@@ -0,0 +1,10 @@
+import { getFixture } from './test-utils';
+import parseGitDiff from '../parse-git-diff';
+
+describe('deleted-empty-file', () => {
+  const fixture = getFixture('deleted-empty-file');
+
+  it('parse `deleted-empty-file`', () => {
+    expect(parseGitDiff(fixture)).toMatchSnapshot();
+  });
+});

src/parse-git-diff.ts

@@ -59,7 +59,10 @@ function parseFileChange(ctx: Context): AnyFileChange | undefined {
     if (!extHeader) {
       break;
     }
-    if (extHeader.type === ExtendedHeader.Deleted) isDeleted = true;
+    if (extHeader.type === ExtendedHeader.Deleted) {
+      isDeleted = true;
+      pathBefore = comparisonLineParsed?.from || '';
+    }
     if (extHeader.type === ExtendedHeader.NewFile) {
       isNew = true;
       pathAfter = comparisonLineParsed?.to || '';
@@ -77,33 +80,30 @@ function parseFileChange(ctx: Context): AnyFileChange | undefined {
   const changeMarkers = parseChangeMarkers(ctx);
   const chunks = parseChunks(ctx);
 
-  if (isDeleted && changeMarkers) {
+  if (isDeleted && chunks.length && chunks[0].type === 'BinaryFilesChunk') {
     return {
       type: FileType.Deleted,
       chunks,
-      path: changeMarkers.deleted,
+      path: chunks[0].pathBefore,
     };
-  } else if (
-    isDeleted &&
-    chunks.length &&
-    chunks[0].type === 'BinaryFilesChunk'
-  ) {
+  }
+  if (isDeleted) {
     return {
       type: FileType.Deleted,
       chunks,
-      path: chunks[0].pathBefore,
+      path: changeMarkers?.deleted || pathBefore,
     };
-  } else if (isNew) {
+  } else if (isNew && chunks.length && chunks[0].type === 'BinaryFilesChunk') {
     return {
       type: FileType.Added,
       chunks,
-      path: changeMarkers ? changeMarkers.added : pathAfter,
+      path: chunks[0].pathAfter,
     };
-  } else if (isNew && chunks.length && chunks[0].type === 'BinaryFilesChunk') {
+  } else if (isNew) {
     return {
       type: FileType.Added,
       chunks,
-      path: chunks[0].pathAfter,
+      path: changeMarkers?.added || pathAfter,
     };
   } else if (isRename) {
     return {