feat: start to log pub get output if it runs for more than 10s (#286)

packages/melos/lib/src/commands/bootstrap.dart

@@ -203,13 +203,21 @@ mixin _BootstrapMixin on _CleanMixin {
       process.stdin.writeln(r'exit $?');
     }
 
+    const logTimeout = Duration(seconds: 10);
+    final packagePrefix = '[${AnsiStyles.blue.bold(package.name)}]: ';
+    void Function(String) logLineTo(void Function(String)? log) =>
+        (line) => log?.call('$packagePrefix$line');
+
     // We always fully consume stdout and stderr. This is required to prevent
-    // leaking resources and to ensure that the process exits. We
-    // need stdout and stderr in case of an error. Otherwise, we don't care
-    // about the output, don't wait for it to finish and don't handle errors.
-    // We just make sure the output streams are drained.
-    final stdout = utf8.decodeStream(process.stdout);
-    final stderr = utf8.decodeStream(process.stderr);
+    // leaking resources and to ensure that the process exits.
+    final stdout = process.stdout.toStringAndLogAfterTimeout(
+      timeout: logTimeout,
+      log: logLineTo(logger?.stdout),
+    );
+    final stderr = process.stderr.toStringAndLogAfterTimeout(
+      timeout: logTimeout,
+      log: logLineTo(logger?.stderr),
+    );
 
     final exitCode = await process.exitCode;
 

packages/melos/lib/src/common/utils.dart

@@ -497,3 +497,29 @@ extension StreamUtils<T> on Stream<T> {
     }
   }
 }
+
+extension Utf8StreamUtils on Stream<List<int>> {
+  /// Fully consumes this stream and returns the decoded string, while also
+  /// starting to call [log] after [timeout] has elapsed for the previously
+  /// decoded lines and all subsequent lines.
+  Future<String> toStringAndLogAfterTimeout({
+    required Duration timeout,
+    required void Function(String) log,
+  }) async {
+    final bufferedLines = <String>[];
+    final stopwatch = Stopwatch()..start();
+    return transform(utf8.decoder).transform(const LineSplitter()).map((line) {
+      if (stopwatch.elapsed >= timeout) {
+        if (bufferedLines.isNotEmpty) {
+          bufferedLines.forEach(log);
+          bufferedLines.clear();
+        }
+        log(line);
+      } else {
+        bufferedLines.add(line);
+      }
+
+      return line;
+    }).join('\n');
+  }
+}