- Improved formatting when specifying source on encodePrioritizedSourceChanges/matcherNormalizedPrioritizedSourceChangeSnapshot

Author: rrousselGit

packages/custom_lint_core/CHANGELOG.md

@@ -1,3 +1,7 @@
+## Unreleased patch
+
+- Improved formatting when specifying `source` on `encodePrioritizedSourceChanges`/`matcherNormalizedPrioritizedSourceChangeSnapshot`
+
 ## 0.5.13 - 2024-02-03
 
 - Improved formatting when specifying `source` on `encodePrioritizedSourceChanges`/`matcherNormalizedPrioritizedSourceChangeSnapshot`

packages/custom_lint_core/lib/src/matcher.dart

@@ -1,6 +1,8 @@
 import 'dart:convert';
 import 'dart:io';
+import 'dart:math';
 
+import 'package:analyzer/source/line_info.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:analyzer_plugin/protocol/protocol_generated.dart';
 import 'package:matcher/matcher.dart';
@@ -19,6 +21,8 @@ String encodePrioritizedSourceChanges(
   String? source,
 }) {
   if (source != null) {
+    final sourceLineInfo = LineInfo.fromContent(source);
+
     final buffer = StringBuffer();
 
     for (final prioritizedSourceChange in changes) {
@@ -29,6 +33,8 @@ String encodePrioritizedSourceChanges(
         prioritizedSourceChange.change.edits.expand((element) => element.edits),
       );
 
+      final outputLineInfo = LineInfo.fromContent(output);
+
       // Get the offset of the first changed character between output and source.
       var firstDiffOffset = 0;
       for (; firstDiffOffset < source.length; firstDiffOffset++) {
@@ -49,17 +55,58 @@ String encodePrioritizedSourceChanges(
         }
       }
 
-      buffer.writeln('<<<< start: $firstDiffOffset -- end: $endSourceOffset');
-      if (firstDiffOffset != endSourceOffset) {
-        buffer.writeln(source.substring(firstDiffOffset, endSourceOffset));
+      final firstChangedLine =
+          sourceLineInfo.getLocation(firstDiffOffset).lineNumber - 1;
+
+      void writeDiff({
+        required String file,
+        required LineInfo lineInfo,
+        required int endOffset,
+        required String token,
+        required int leadingCount,
+        required int trailingCount,
+      }) {
+        final lastChangedLine = lineInfo.getLocation(endOffset).lineNumber - 1;
+        final endLine =
+            min(lastChangedLine + trailingCount, lineInfo.lineCount - 1);
+        for (var line = max(0, firstChangedLine - leadingCount);
+            line <= endLine;
+            line++) {
+          final changed = line >= firstChangedLine && line <= lastChangedLine;
+          if (changed) buffer.write(token);
+
+          final endOfSource = !(line + 1 < lineInfo.lineCount);
+
+          buffer.write(
+            file.substring(
+              lineInfo.getOffsetOfLine(line),
+              endOfSource ? null : lineInfo.getOffsetOfLine(line + 1) - 1,
+            ),
+          );
+          if (!endOfSource) buffer.writeln();
+        }
       }
 
-      buffer.writeln('==== start: $firstDiffOffset -- end: $endOutputOffset');
-      if (firstDiffOffset != endOutputOffset) {
-        buffer.writeln(output.substring(firstDiffOffset, endOutputOffset));
-      }
+      buffer.writeln('=== diff (starting at line ${firstChangedLine + 1})');
+      writeDiff(
+        file: source,
+        lineInfo: sourceLineInfo,
+        endOffset: endSourceOffset,
+        leadingCount: 2,
+        trailingCount: 0,
+        token: '- ',
+      );
+
+      writeDiff(
+        file: output,
+        lineInfo: outputLineInfo,
+        endOffset: endOutputOffset,
+        leadingCount: 0,
+        trailingCount: 2,
+        token: '+ ',
+      );
 
-      buffer.writeln('>>>>');
+      buffer.writeln('===');
     }
 
     return buffer.toString();

packages/custom_lint_core/test/assist_test.dart

@@ -44,15 +44,15 @@ void main() {
     expect(
       await changes,
       matcherNormalizedPrioritizedSourceChangeSnapshot(
-        'snapshot.snap',
+        'snapshot.diff',
         source: fileSource,
       ),
     );
     expect(
       await changes,
       isNot(
         matcherNormalizedPrioritizedSourceChangeSnapshot(
-          'snapshot2.snap',
+          'snapshot2.diff',
           source: fileSource,
         ),
       ),
@@ -62,15 +62,15 @@ void main() {
       await changes2,
       isNot(
         matcherNormalizedPrioritizedSourceChangeSnapshot(
-          'snapshot.snap',
+          'snapshot.diff',
           source: fileSource,
         ),
       ),
     );
     expect(
       await changes2,
       matcherNormalizedPrioritizedSourceChangeSnapshot(
-        'snapshot2.snap',
+        'snapshot2.diff',
         source: fileSource,
       ),
     );
@@ -137,15 +137,15 @@ void main() {
     expect(
       await changes,
       matcherNormalizedPrioritizedSourceChangeSnapshot(
-        'snapshot.snap',
+        'snapshot.diff',
         source: fileSource,
       ),
     );
     expect(
       await changes,
       isNot(
         matcherNormalizedPrioritizedSourceChangeSnapshot(
-          'snapshot2.snap',
+          'snapshot2.diff',
           source: fileSource,
         ),
       ),
@@ -155,15 +155,15 @@ void main() {
       await changes2,
       isNot(
         matcherNormalizedPrioritizedSourceChangeSnapshot(
-          'snapshot.snap',
+          'snapshot.diff',
           source: fileSource,
         ),
       ),
     );
     expect(
       await changes2,
       matcherNormalizedPrioritizedSourceChangeSnapshot(
-        'snapshot2.snap',
+        'snapshot2.diff',
         source: fileSource,
       ),
     );

packages/custom_lint_core/test/fix_test.dart

@@ -33,15 +33,15 @@ void main() {
     expect(
       await changes,
       matcherNormalizedPrioritizedSourceChangeSnapshot(
-        'snapshot.snap',
+        'snapshot.diff',
         source: fileSource,
       ),
     );
     expect(
       await changes,
       isNot(
         matcherNormalizedPrioritizedSourceChangeSnapshot(
-          'snapshot2.snap',
+          'snapshot2.diff',
           source: fileSource,
         ),
       ),
@@ -51,15 +51,15 @@ void main() {
       await changes2,
       isNot(
         matcherNormalizedPrioritizedSourceChangeSnapshot(
-          'snapshot.snap',
+          'snapshot.diff',
           source: fileSource,
         ),
       ),
     );
     expect(
       await changes2,
       matcherNormalizedPrioritizedSourceChangeSnapshot(
-        'snapshot2.snap',
+        'snapshot2.diff',
         source: fileSource,
       ),
     );
@@ -81,15 +81,15 @@ void main() {
     expect(
       await changes,
       matcherNormalizedPrioritizedSourceChangeSnapshot(
-        'snapshot.snap',
+        'snapshot.diff',
         source: fileSource,
       ),
     );
     expect(
       await changes,
       isNot(
         matcherNormalizedPrioritizedSourceChangeSnapshot(
-          'snapshot2.snap',
+          'snapshot2.diff',
           source: fileSource,
         ),
       ),

packages/custom_lint_core/test/snapshot.diff

@@ -0,0 +1,7 @@
+Message: `MyAssist`
+=== diff (starting at line 2)
+void main() {
+-   print('Hello world');
++   Helloprint('Hello world');
+}
+===

packages/custom_lint_core/test/snapshot.snap

@@ -0,0 +1,7 @@
+Message: `Another`
+=== diff (starting at line 2)
+void main() {
+-   print('Hello world');
++   Helloprint('Hello world');
+}
+===