lib/src/runner/load_exception.dart

// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:isolate';

import 'package:path/path.dart' as p;
import 'package:source_span/source_span.dart';

import '../utils.dart';

/// A regular expression for matching filename annotations in
/// [IsolateSpawnException] messages.
final _isolateFileRegExp =
    new RegExp(r"^'(file:/[^']+)': (error|warning): ", multiLine: true);

class LoadException implements Exception {
  final String path;

  final innerError;

  LoadException(this.path, this.innerError);

  String toString({bool color: false}) {
    var buffer = new StringBuffer();
    if (color) buffer.write('\u001b[31m'); // red
    buffer.write('Failed to load "$path":');
    if (color) buffer.write('\u001b[0m'); // no color

    var innerString = getErrorMessage(innerError);
    if (innerError is IsolateSpawnException) {
      // If this is a parse error, clean up the noisy filename annotations.
      innerString = innerString.replaceAllMapped(_isolateFileRegExp, (match) {
        if (p.fromUri(match[1]) == p.absolute(path)) return "";
        return "${p.prettyUri(match[1])}: ";
      });

      // If this is a file system error, get rid of both the preamble and the
      // useless stack trace.

      // This message was used prior to 1.11.0-dev.3.0.
      innerString = innerString.replaceFirst(
          "Unhandled exception:\n"
          "Uncaught Error: Load Error: ",
          "");

      // This message was used after 1.11.0-dev.3.0.
      innerString = innerString.replaceFirst(
          "Unhandled exception:\n"
          "Load Error for ",
          "");

      innerString = innerString.replaceFirst("FileSystemException: ", "");
      innerString = innerString.split("Stack Trace:\n").first.trim();
    }
    if (innerError is SourceSpanException) {
      innerString =
          innerError.toString(color: color).replaceFirst(" of $path", "");
    }

    buffer.write(innerString.contains("\n") ? "\n" : " ");
    buffer.write(innerString);
    return buffer.toString();
  }
}