fix: --flutter-version=hash stopped working (#3478)

packages/shorebird_cli/lib/src/shorebird_flutter.dart

@@ -214,29 +214,37 @@ class ShorebirdFlutter {
         .firstOrNull;
   }
 
+  /// Pattern for a valid git hash (4-40 hex characters).
+  /// Git allows short hashes as long as they're unambiguous.
+  static final _gitHashPattern = RegExp(r'^[0-9a-fA-F]{4,40}$');
+
   /// Translates [versionOrHash] into a Flutter revision. If this is a semver
-  /// version, it will simply parse that into a [Version]. If not, it will
-  /// attempt to look up the Flutter version for the provided revision hash and
-  /// return the hash if a version is found, or null if not.
+  /// version, it will look up the git revision for that version. If not, it
+  /// will check if it's a valid git hash that exists in the local Flutter repo.
+  ///
+  /// Returns the full hash if valid, or null if it's neither a valid semver
+  /// version nor a valid git hash that exists locally.
   Future<String?> resolveFlutterRevision(String versionOrHash) async {
     final parsedVersion = tryParseVersion(versionOrHash);
     if (parsedVersion != null) {
       return getRevisionForVersion(versionOrHash);
     }
 
-    // If we were unable to parse the version, assume it's a revision hash.
-    try {
-      final version = await getVersionForRevision(
-        flutterRevision: versionOrHash,
-      );
-      if (version != null) {
-        return versionOrHash;
-      }
-    } on Exception {
+    // If we were unable to parse the version, check if it's a valid git hash.
+    if (!_gitHashPattern.hasMatch(versionOrHash)) {
       return null;
     }
 
-    return null;
+    // Verify the hash exists locally by resolving it to its full hash.
+    try {
+      final fullHash = await git.revParse(
+        revision: versionOrHash,
+        directory: _workingDirectory(),
+      );
+      return fullHash;
+    } on ProcessException {
+      return null;
+    }
   }
 
   /// Translates [versionOrHash] into a Flutter [Version]. If [versionOrHash]

packages/shorebird_cli/test/src/shorebird_flutter_test.dart

@@ -313,62 +313,63 @@ Tools • Dart 3.0.6 • DevTools 2.23.1''');
         );
       });
 
-      group('when input is a commit hash that maps to a Flutter version', () {
+      group('when input is a valid git hash that exists locally', () {
+        const fullHash = 'eead750584a909f506eb6fc111ece5d8fed4aa39';
+
         setUp(() {
           when(
-            () => git.forEachRef(
+            () => git.revParse(
+              revision: any(named: 'revision'),
               directory: any(named: 'directory'),
-              contains: any(named: 'contains'),
-              format: any(named: 'format'),
-              pattern: any(named: 'pattern'),
             ),
-          ).thenAnswer((_) async => 'origin/flutter_release/1.2.3');
+          ).thenAnswer((_) async => fullHash);
         });
 
-        test('returns the input string', () async {
+        test('returns full hash for full input', () async {
+          final revision = await runWithOverrides(
+            () => shorebirdFlutter.resolveFlutterRevision(fullHash),
+          );
+          expect(revision, equals(fullHash));
+        });
+
+        test('returns full hash for short input', () async {
           final revision = await runWithOverrides(
             () => shorebirdFlutter.resolveFlutterRevision('deadbeef'),
           );
-          expect(revision, equals('deadbeef'));
+          expect(revision, equals(fullHash));
         });
       });
 
-      group(
-        'when input is not a commit hash that maps to a Flutter version',
-        () {
-          setUp(() {
-            when(
-              () => git.forEachRef(
-                directory: any(named: 'directory'),
-                contains: any(named: 'contains'),
-                format: any(named: 'format'),
-                pattern: any(named: 'pattern'),
-              ),
-            ).thenAnswer((_) async => '');
-          });
-
-          test('returns the input string', () async {
-            final revision = await runWithOverrides(
-              () => shorebirdFlutter.resolveFlutterRevision('not-a-version'),
-            );
-            expect(revision, isNull);
-          });
-        },
-      );
-
-      group('when exception occurs doing revision lookup', () {
+      group('when input is a valid git hash format but does not exist', () {
         setUp(() {
           when(
-            () => git.forEachRef(
+            () => git.revParse(
+              revision: any(named: 'revision'),
               directory: any(named: 'directory'),
-              contains: any(named: 'contains'),
-              format: any(named: 'format'),
-              pattern: any(named: 'pattern'),
             ),
-          ).thenThrow(Exception('oops'));
+          ).thenThrow(
+            const ProcessException('git', ['rev-parse']),
+          );
         });
 
         test('returns null', () async {
+          const validHash = 'eead750584a909f506eb6fc111ece5d8fed4aa39';
+          final revision = await runWithOverrides(
+            () => shorebirdFlutter.resolveFlutterRevision(validHash),
+          );
+          expect(revision, isNull);
+        });
+      });
+
+      group('when input is not a valid git hash format', () {
+        test('returns null for too-short hash', () async {
+          final revision = await runWithOverrides(
+            () => shorebirdFlutter.resolveFlutterRevision('abc'),
+          );
+          expect(revision, isNull);
+        });
+
+        test('returns null for non-hex string', () async {
           final revision = await runWithOverrides(
             () => shorebirdFlutter.resolveFlutterRevision('not-a-version'),
           );