Handle empty trailing lines in diff patches to improve parsing accuracy

Author: robertpiosik

packages/vscode/src/commands/apply-chat-response-command/utils/clipboard-parser/clipboard-parser.spec.ts

@@ -2057,5 +2057,26 @@ describe('clipboard-parser', () => {
         content: load_test_case_file('diffs', test_case, '1-file.txt')
       })
     })
+
+    it('parses diff format with unnecessary empty lines', () => {
+      const test_case = 'diff-markdown-unnecessary-empty-lines'
+      const text = load_test_case_file(
+        'diffs',
+        test_case,
+        'diff-markdown-path-above.txt'
+      )
+      const result = parse_response({
+        response: text,
+        is_single_root_folder_workspace: true
+      })
+
+      expect(result).toHaveLength(1)
+      expect(result[0]).toMatchObject({
+        type: 'diff',
+        file_path: 'src/index.ts',
+        content: load_test_case_file('diffs', test_case, '1-file.txt')
+      })
+    })
   })
 })
+

packages/vscode/src/commands/apply-chat-response-command/utils/clipboard-parser/extract-diff-patches/extract-diffs.ts

@@ -259,12 +259,15 @@ const process_collected_patch_lines = (params: {
   patch_lines_array: string[]
   is_single_root: boolean
 }): Diff | null => {
-  const joined_patch_text_for_checks = params.patch_lines_array.join('\n')
+  const lines = [...params.patch_lines_array]
+  while (lines.length > 0 && lines[lines.length - 1].trim() === '') {
+    lines.pop()
+  }
+
+  const joined_patch_text_for_checks = lines.join('\n')
   if (joined_patch_text_for_checks.trim() == '') return null
 
-  const { from_path, to_path } = extract_paths_from_lines(
-    params.patch_lines_array
-  )
+  const { from_path, to_path } = extract_paths_from_lines(lines)
 
   const is_new_file = from_path == '/dev/null'
   const is_deleted_file = to_path == '/dev/null'
@@ -283,15 +286,15 @@ const process_collected_patch_lines = (params: {
       message: 'Could not extract file path from collected patch lines.',
       data: {
         clipboard_start: joined_patch_text_for_checks.substring(0, 200),
-        lines_count: params.patch_lines_array.length
+        lines_count: lines.length
       }
     })
     return null
   }
 
-  const patch_start_idx = find_patch_start_index(params.patch_lines_array)
+  const patch_start_idx = find_patch_start_index(lines)
   let content_str = build_patch_content({
-    lines: params.patch_lines_array,
+    lines,
     file_path,
     patch_start_index: patch_start_idx,
     is_single_root: params.is_single_root

packages/vscode/src/commands/apply-chat-response-command/utils/clipboard-parser/test-cases/diffs/diff-inner-triple-backticks/1-file.txt

@@ -12,4 +12,3 @@
      ```
 
  ## Usage
- 

packages/vscode/src/commands/apply-chat-response-command/utils/clipboard-parser/test-cases/diffs/diff-markdown-unnecessary-empty-lines/1-file.txt

@@ -0,0 +1,6 @@
+--- a/src/index.ts
++++ b/src/index.ts
+@@ -1,3 +1,3 @@
+ console.log("hello")
+-console.log("old message")
++console.log("new message")

packages/vscode/src/commands/apply-chat-response-command/utils/clipboard-parser/test-cases/diffs/diff-markdown-unnecessary-empty-lines/diff-markdown-path-above.txt

@@ -0,0 +1,10 @@
+### Updated file: `src/index.ts`
+
+```diff
+@@ -1,3 +1,3 @@
+ console.log("hello")
+-console.log("old message")
++console.log("new message")
+
+
+```

packages/vscode/src/commands/apply-chat-response-command/utils/diff-processor.ts

@@ -131,7 +131,6 @@ export const apply_diff = (params: {
     let replace_chunks = []
 
     let inside_replace_block = false
-    let has_context_lines = false
 
     for (let i = 0; i < patch_lines_normalized.length; i++) {
       const line = patch_lines_normalized[i]
@@ -146,7 +145,6 @@ export const apply_diff = (params: {
         search_chunks = []
         replace_chunks = []
         inside_replace_block = false
-        has_context_lines = false
       }
 
       if (line.startsWith('-') || line.startsWith('~')) {
@@ -161,7 +159,6 @@ export const apply_diff = (params: {
 
           search_chunks = []
           replace_chunks = []
-          has_context_lines = false
         }
 
         if (line.startsWith('--')) {
@@ -177,10 +174,8 @@ export const apply_diff = (params: {
         // Also replace unchanged lines
         if (line.startsWith('~nnn')) {
           replace_chunks.push(line_original.replace(/^~nnn/, '') + '\n')
-          has_context_lines = true
         } else if (line.startsWith('~')) {
           replace_chunks.push(line_original.replace(/^~/, '') + '\n')
-          has_context_lines = true
         }
 
         continue