Add stacktrace_test

tests/compiler/dart2js/sourcemaps/load.dart

+// Copyright (c) 2016, 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.
+
+/// Loads a source map file and outputs a human-readable version of it.
+
+library load;
+
+import 'dart:convert';
+import 'dart:io';
+import 'package:source_maps/source_maps.dart';
+
+void main(List<String> args) {
+  if (args.isEmpty) {
+    print('''
+Usage: load <dir-containing 'out.js.map'>
+   or: load <source-map-file> [<human-readable-source-map-file>]''');
+    exit(1);
+  }
+
+  File humanReadableSourceMapFile;
+  File sourceMapFile;
+  if (args.length == 1 && new Directory(args[0]).existsSync()) {
+    humanReadableSourceMapFile = new File('${args[0]}/out.js.map2');
+    sourceMapFile = new File('${args[0]}/out.js.map');
+  } else {
+    sourceMapFile = new File(args[0]);
+    if (args.length > 1) {
+      humanReadableSourceMapFile = new File(args[1]);
+    }
+  }
+  mainInternal(sourceMapFile, humanReadableSourceMapFile);
+}
+
+void mainInternal(File sourceMapFile, File humanReadableSourceMapFile) {
+  SingleMapping sourceMap =
+      new SingleMapping.fromJson(JSON.decode(sourceMapFile.readAsStringSync()));
+  String humanReadableSourceMap = convertToHumanReadableSourceMap(sourceMap);
+  if (humanReadableSourceMapFile != null) {
+    humanReadableSourceMapFile.writeAsStringSync(humanReadableSourceMap);
+  } else {
+    print(humanReadableSourceMap);
+  }
+}
+
+String convertToHumanReadableSourceMap(SingleMapping sourceMap) {
+  StringBuffer sb = new StringBuffer();
+  sb.write('{\n');
+  sb.write('  "file": "${sourceMap.targetUrl}",\n');
+  sb.write('  "sourceRoot": "${sourceMap.sourceRoot}",\n');
+  sb.write('  "sources": {\n');
+  for (int index = 0; index < sourceMap.urls.length; index++) {
+    if (index > 0) {
+      sb.write(',\n');
+    }
+    sb.write('    "$index": "${sourceMap.urls[index]}"');
+  }
+  sb.write('\n  },\n');
+  sb.write('  "lines": [\n');
+  bool needsComma = false;
+  for (int lineIndex = 0; lineIndex < sourceMap.lines.length; lineIndex++) {
+    TargetLineEntry lineEntry = sourceMap.lines[lineIndex];
+    int line = lineEntry.line + 1;
+    for (int entryIndex = 0;
+        entryIndex < lineEntry.entries.length;
+        entryIndex++) {
+      TargetEntry entry = lineEntry.entries[entryIndex];
+      int columnStart = entry.column + 1;
+      int columnEnd;
+      String position;
+      if (entryIndex + 1 < lineEntry.entries.length) {
+        columnEnd = lineEntry.entries[entryIndex + 1].column + 1;
+        position = '$line,$columnStart-$columnEnd';
+      } else {
+        position = '$line,$columnStart-';
+      }
+      if (entry.sourceUrlId != null) {
+        int sourceUrlId = entry.sourceUrlId;
+        int sourceLine = entry.sourceLine + 1;
+        int sourceColumn = entry.sourceColumn + 1;
+        if (needsComma) {
+          sb.write(',\n');
+        }
+        sb.write('    {"target": "$position"');
+        sb.write(', "source": "$sourceUrlId:$sourceLine,$sourceColumn"');
+        if (entry.sourceNameId != null) {
+          sb.write(', "name": "${sourceMap.names[entry.sourceNameId]}"');
+        }
+        sb.write('}');
+        needsComma = true;
+      }
+    }
+  }
+  sb.write('\n  ]\n');
+  sb.write('}');
+  return sb.toString();
+}