Adapt xcresult parser for Xcode 16 changes (flutter#172596)

This PR updates the iOS build process to support breaking changes in
Xcode 16's xcresulttool. The xcresulttool get command, which Flutter
uses to parse native build issues, is deprecated and replaced by the new
xcresulttool get build-results command. This new command also introduces
a completely new, flatter JSON output format.

To address this while maintaining backwards compatibility, this change
introduces a two-part solution:
- The XCResultGenerator now detects the Xcode version and conditionally
calls the appropriate command (get build-results for Xcode 16+ and get
for older versions).
- The XCResult parser has been refactored to be "bilingual," meaning it
can intelligently detect the JSON structure and parse both the old
(nested) and new (flat) formats correctly.
- This ensures that native iOS build errors and warnings continue to be
correctly parsed and displayed to the user on all supported Xcode
versions.

Fixes flutter#151502 

## Pre-launch Checklist

- [X] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [X] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [X] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [X] I signed the [CLA].
- [X] I listed at least one issue that this PR fixes in the description
above.
- [X] I updated/added relevant documentation (doc comments with `///`).
- [X] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [X] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [X] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

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[Data Driven Fixes]:
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Author: okorohelijah

packages/flutter_tools/lib/src/ios/xcresult.dart

@@ -40,17 +40,25 @@ class XCResultGenerator {
     List<XCResultIssueDiscarder> issueDiscarders = const <XCResultIssueDiscarder>[],
   }) async {
     final Version? xcodeVersion = xcode.currentVersion;
-    final RunResult result = await processUtils.run(<String>[
-      ...xcode.xcrunCommand(),
-      'xcresulttool',
-      'get',
-      // See https://github.com/flutter/flutter/issues/151502
-      if (xcodeVersion != null && xcodeVersion >= Version(16, 0, 0)) '--legacy',
-      '--path',
-      resultPath,
-      '--format',
-      'json',
-    ]);
+    final bool useNewCommand = xcodeVersion != null && xcodeVersion >= Version(16, 0, 0);
+
+    final baseCommand = <String>[...xcode.xcrunCommand(), 'xcresulttool'];
+
+    if (useNewCommand) {
+      baseCommand.addAll(<String>[
+        'get',
+        'build-results',
+        '--path',
+        resultPath,
+        '--format',
+        'json',
+      ]);
+    } else {
+      baseCommand.addAll(<String>['get', '--path', resultPath, '--format', 'json']);
+    }
+
+    final RunResult result = await processUtils.run(baseCommand);
+
     if (result.exitCode != 0) {
       return XCResult.failed(errorMessage: result.stderr);
     }
@@ -59,9 +67,6 @@ class XCResultGenerator {
     }
     final Object? resultJson = json.decode(result.stdout);
     if (resultJson == null || resultJson is! Map<String, Object?>) {
-      // If json parsing failed, indicate such error.
-      // This also includes the top level json object is an array, which indicates
-      // the structure of the json is changed and this parser class possibly needs to update for this change.
       return XCResult.failed(errorMessage: 'xcresult parser: Unrecognized top level json format.');
     }
     return XCResult(resultJson: resultJson, issueDiscarders: issueDiscarders);
@@ -80,40 +85,71 @@ class XCResult {
   }) {
     final issues = <XCResultIssue>[];
 
-    final Object? issuesMap = resultJson['issues'];
-    if (issuesMap == null || issuesMap is! Map<String, Object?>) {
-      return XCResult.failed(errorMessage: 'xcresult parser: Failed to parse the issues map.');
-    }
+    /// Detect which xcresult JSON format is being used to ensure backwards compatibility.
+    ///
+    /// Xcode 16 introduced a new `get build-results` command with a flatter JSON structure.
+    /// Older versions use the original `get` command with a deeply nested structure.
+    /// We differentiate them by checking for the presence of top-level 'errors' or 'warnings'
+    /// keys, which are unique to the modern format.
 
-    final Object? errorSummaries = issuesMap['errorSummaries'];
-    if (errorSummaries is Map<String, Object?>) {
+    if (resultJson.containsKey('errors') || resultJson.containsKey('warnings')) {
       issues.addAll(
-        _parseIssuesFromIssueSummariesJson(
+        _parseIssuesFromNewFormat(
           type: XCResultIssueType.error,
-          issueSummariesJson: errorSummaries,
-          issueDiscarder: issueDiscarders,
+          jsonList: resultJson['errors'],
+          issueDiscarders: issueDiscarders,
         ),
       );
-    }
-
-    final Object? warningSummaries = issuesMap['warningSummaries'];
-    if (warningSummaries is Map<String, Object?>) {
       issues.addAll(
-        _parseIssuesFromIssueSummariesJson(
+        _parseIssuesFromNewFormat(
           type: XCResultIssueType.warning,
-          issueSummariesJson: warningSummaries,
-          issueDiscarder: issueDiscarders,
+          jsonList: resultJson['warnings'],
+          issueDiscarders: issueDiscarders,
         ),
       );
+    } else {
+      final Object? issuesMap = resultJson['issues'];
+
+      if (issuesMap is! Map<String, Object?>) {
+        return XCResult.failed(errorMessage: 'xcresult parser: Failed to parse the issues map.');
+      }
+
+      final Object? errorSummaries = issuesMap['errorSummaries'];
+      if (errorSummaries is Map<String, Object?>) {
+        issues.addAll(
+          _parseIssuesFromXcode15Format(
+            type: XCResultIssueType.error,
+            issueSummariesJson: errorSummaries,
+            issueDiscarder: issueDiscarders,
+          ),
+        );
+      }
+      final Object? warningSummaries = issuesMap['warningSummaries'];
+      if (warningSummaries is Map<String, Object?>) {
+        issues.addAll(
+          _parseIssuesFromXcode15Format(
+            type: XCResultIssueType.warning,
+            issueSummariesJson: warningSummaries,
+            issueDiscarder: issueDiscarders,
+          ),
+        );
+      }
+      final Object? actionsMap = resultJson['actions'];
+      if (actionsMap is Map<String, Object?>) {
+        final List<XCResultIssue> actionIssues = _parseActionIssues(
+          actionsMap,
+          issueDiscarders: issueDiscarders,
+        );
+        issues.addAll(actionIssues);
+      }
     }
 
-    final Object? actionsMap = resultJson['actions'];
-    if (actionsMap is Map<String, Object?>) {
-      final List<XCResultIssue> actionIssues = _parseActionIssues(
-        actionsMap,
-        issueDiscarders: issueDiscarders,
-      );
-      issues.addAll(actionIssues);
+    if (issues.isEmpty &&
+        resultJson['issues'] == null &&
+        resultJson['actions'] == null &&
+        resultJson['errors'] == null &&
+        resultJson['warnings'] == null) {
+      return XCResult.failed(errorMessage: 'xcresult parser: Failed to parse the issues map.');
     }
 
     return XCResult._(issues: issues);
@@ -143,7 +179,6 @@ class XCResult {
     this.parsingErrorMessage,
   });
 
-  /// The issues in the xcresult file.
   final List<XCResultIssue> issues;
 
   /// Indicate if the xcresult was successfully parsed.
@@ -157,33 +192,24 @@ class XCResult {
   final String? parsingErrorMessage;
 }
 
-/// An issue object in the XCResult
 class XCResultIssue {
   /// Construct an `XCResultIssue` object from `issueJson`.
   ///
   /// `issueJson` is the object at xcresultJson[['actions']['_values'][0]['buildResult']['issues']['errorSummaries'/'warningSummaries']['_values'].
-  factory XCResultIssue({
+  factory XCResultIssue.fromOldFormat({
     required XCResultIssueType type,
     required Map<String, Object?> issueJson,
   }) {
-    // Parse type.
     final Object? issueSubTypeMap = issueJson['issueType'];
     String? subType;
     if (issueSubTypeMap is Map<String, Object?>) {
-      final Object? subTypeValue = issueSubTypeMap['_value'];
-      if (subTypeValue is String) {
-        subType = subTypeValue;
-      }
+      subType = issueSubTypeMap['_value'] as String?;
     }
 
-    // Parse message.
     String? message;
     final Object? messageMap = issueJson['message'];
     if (messageMap is Map<String, Object?>) {
-      final Object? messageValue = messageMap['_value'];
-      if (messageValue is String) {
-        message = messageValue;
-      }
+      message = messageMap['_value'] as String?;
     }
 
     final warnings = <String>[];
@@ -215,7 +241,37 @@ class XCResultIssue {
     );
   }
 
-  /// Create a [XCResultIssue] without JSON parsing for testing.
+  /// Construct an `XCResultIssue` object from the (Xcode 16+) format `issueJson`.
+  factory XCResultIssue.fromNewFormat({
+    required XCResultIssueType type,
+    required Map<String, Object?> issueJson,
+  }) {
+    final message = issueJson['message'] as String?;
+
+    final subType = issueJson['issueType'] as String?;
+
+    String? location;
+    final warnings = <String>[];
+
+    final sourceUrl = issueJson['sourceURL'] as String?;
+    if (sourceUrl != null) {
+      location = _convertUrlToLocationString(sourceUrl);
+      if (location == null) {
+        warnings.add(
+          '(XCResult) The `sourceURL` exists but it failed to be parsed. url: $sourceUrl',
+        );
+      }
+    }
+
+    return XCResultIssue._(
+      type: type,
+      subType: subType,
+      message: message,
+      location: location,
+      warnings: warnings,
+    );
+  }
+
   @visibleForTesting
   factory XCResultIssue.test({
     XCResultIssueType type = XCResultIssueType.error,
@@ -235,10 +291,10 @@ class XCResultIssue {
 
   XCResultIssue._({
     required this.type,
-    required this.subType,
-    required this.message,
-    required this.location,
-    required this.warnings,
+    this.subType,
+    this.message,
+    this.location,
+    this.warnings = const <String>[],
   });
 
   /// The type of the issue.
@@ -314,11 +370,10 @@ class XCResultIssueDiscarder {
 }
 
 // A typical location url string looks like file:///foo.swift#CharacterRangeLen=0&EndingColumnNumber=82&EndingLineNumber=7&StartingColumnNumber=82&StartingLineNumber=7.
-//
-// This function converts it to something like: /foo.swift:<StartingLineNumber>:<StartingColumnNumber>.
+// This function is now used by BOTH the old and new parsers.
 String? _convertUrlToLocationString(String url) {
   final Uri? fragmentLocation = Uri.tryParse(url);
-  if (fragmentLocation == null) {
+  if (fragmentLocation == null || !fragmentLocation.hasFragment) {
     return null;
   }
   // Parse the fragment as a query of key-values:
@@ -334,7 +389,6 @@ String? _convertUrlToLocationString(String url) {
   return '${fileLocation.path}$startingLineNumber$startingColumnNumber';
 }
 
-// Determine if an `issue` should be discarded based on the `discarder`.
 bool _shouldDiscardIssue({
   required XCResultIssue issue,
   required XCResultIssueDiscarder discarder,
@@ -361,7 +415,30 @@ bool _shouldDiscardIssue({
   return false;
 }
 
-List<XCResultIssue> _parseIssuesFromIssueSummariesJson({
+/// Helper to parse issues from the new (Xcode 16+) flat list format.
+List<XCResultIssue> _parseIssuesFromNewFormat({
+  required XCResultIssueType type,
+  required Object? jsonList,
+  required List<XCResultIssueDiscarder> issueDiscarders,
+}) {
+  if (jsonList is! List<Object?>) {
+    return const <XCResultIssue>[];
+  }
+
+  return jsonList
+      .whereType<Map<String, Object?>>()
+      .map((issueJson) => XCResultIssue.fromNewFormat(type: type, issueJson: issueJson))
+      .where((issue) {
+        final bool shouldDiscard = issueDiscarders.any(
+          (discarder) => _shouldDiscardIssue(issue: issue, discarder: discarder),
+        );
+        return !shouldDiscard;
+      })
+      .toList();
+}
+
+/// Helper to parse issues from the old (pre-Xcode 16) format.
+List<XCResultIssue> _parseIssuesFromXcode15Format({
   required XCResultIssueType type,
   required Map<String, Object?> issueSummariesJson,
   required List<XCResultIssueDiscarder> issueDiscarder,
@@ -370,26 +447,26 @@ List<XCResultIssue> _parseIssuesFromIssueSummariesJson({
   final Object? errorsList = issueSummariesJson['_values'];
   if (errorsList is List<Object?>) {
     for (final Object? issueJson in errorsList) {
-      if (issueJson == null || issueJson is! Map<String, Object?>) {
+      if (issueJson is! Map<String, Object?>) {
         continue;
       }
-      final resultIssue = XCResultIssue(type: type, issueJson: issueJson);
+      final resultIssue = XCResultIssue.fromOldFormat(type: type, issueJson: issueJson);
       var discard = false;
       for (final discarder in issueDiscarder) {
         if (_shouldDiscardIssue(issue: resultIssue, discarder: discarder)) {
           discard = true;
           break;
         }
       }
-      if (discard) {
-        continue;
+      if (!discard) {
+        issues.add(resultIssue);
       }
-      issues.add(resultIssue);
     }
   }
   return issues;
 }
 
+/// Helper to parse issues from the `actions` block in the pre-Xcode 16 format.
 List<XCResultIssue> _parseActionIssues(
   Map<String, Object?> actionsMap, {
   required List<XCResultIssueDiscarder> issueDiscarders,
@@ -461,14 +538,13 @@ List<XCResultIssue> _parseActionIssues(
     final Object? testFailureSummaries = actionResultIssues['testFailureSummaries'];
     if (testFailureSummaries is Map<String, Object?>) {
       issues.addAll(
-        _parseIssuesFromIssueSummariesJson(
+        _parseIssuesFromXcode15Format(
           type: XCResultIssueType.error,
           issueSummariesJson: testFailureSummaries,
           issueDiscarder: issueDiscarders,
         ),
       );
     }
   }
-
   return issues;
 }