Roll Observatory packages and add a roll script

packages/dart_style/bin/format.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:convert';
+import 'dart:io';
+
+import 'package:args/args.dart';
+import 'package:dart_style/src/dart_formatter.dart';
+import 'package:dart_style/src/formatter_exception.dart';
+import 'package:dart_style/src/formatter_options.dart';
+import 'package:dart_style/src/io.dart';
+import 'package:dart_style/src/source_code.dart';
+
+void main(List<String> args) {
+  var parser = new ArgParser(allowTrailingOptions: true);
+
+  parser.addFlag("help",
+      abbr: "h", negatable: false, help: "Shows usage information.");
+  parser.addOption("line-length",
+      abbr: "l", help: "Wrap lines longer than this.", defaultsTo: "80");
+  parser.addOption("preserve",
+      help: 'Selection to preserve, formatted as "start:length".');
+  parser.addFlag("dry-run",
+      abbr: "n",
+      negatable: false,
+      help: "Show which files would be modified but make no changes.");
+  parser.addFlag("overwrite",
+      abbr: "w",
+      negatable: false,
+      help: "Overwrite input files with formatted output.");
+  parser.addFlag("machine",
+      abbr: "m",
+      negatable: false,
+      help: "Produce machine-readable JSON output.");
+  parser.addFlag("follow-links",
+      negatable: false,
+      help: "Follow links to files and directories.\n"
+          "If unset, links will be ignored.");
+  parser.addFlag("transform",
+      abbr: "t",
+      negatable: false,
+      help: "Unused flag for compability with the old formatter.");
+
+  var argResults;
+  try {
+    argResults = parser.parse(args);
+  } on FormatException catch (err) {
+    usageError(parser, err.message);
+  }
+
+  if (argResults["help"]) {
+    printUsage(parser);
+    return;
+  }
+
+  // Can only preserve a selection when parsing from stdin.
+  var selection;
+
+  if (argResults["preserve"] != null && argResults.rest.isNotEmpty) {
+    usageError(parser, "Can only use --preserve when reading from stdin.");
+  }
+
+  try {
+    selection = parseSelection(argResults["preserve"]);
+  } on FormatException catch (_) {
+    usageError(
+        parser,
+        '--preserve must be a colon-separated pair of integers, was '
+        '"${argResults['preserve']}".');
+  }
+
+  if (argResults["dry-run"] && argResults["overwrite"]) {
+    usageError(
+        parser, "Cannot use --dry-run and --overwrite at the same time.");
+  }
+
+  checkForReporterCollision(String chosen, String other) {
+    if (!argResults[other]) return;
+
+    usageError(parser, "Cannot use --$chosen and --$other at the same time.");
+  }
+
+  var reporter = OutputReporter.print;
+  if (argResults["dry-run"]) {
+    checkForReporterCollision("dry-run", "overwrite");
+    checkForReporterCollision("dry-run", "machine");
+
+    reporter = OutputReporter.dryRun;
+  } else if (argResults["overwrite"]) {
+    checkForReporterCollision("overwrite", "machine");
+
+    if (argResults.rest.isEmpty) {
+      usageError(parser,
+          "Cannot use --overwrite without providing any paths to format.");
+    }
+
+    reporter = OutputReporter.overwrite;
+  } else if (argResults["machine"]) {
+    reporter = OutputReporter.printJson;
+  }
+
+  var pageWidth;
+
+  try {
+    pageWidth = int.parse(argResults["line-length"]);
+  } on FormatException catch (_) {
+    usageError(
+        parser,
+        '--line-length must be an integer, was '
+        '"${argResults['line-length']}".');
+  }
+
+  var followLinks = argResults["follow-links"];
+
+  var options = new FormatterOptions(reporter,
+      pageWidth: pageWidth, followLinks: followLinks);
+
+  if (argResults.rest.isEmpty) {
+    formatStdin(options, selection);
+  } else {
+    formatPaths(options, argResults.rest);
+  }
+}
+
+List<int> parseSelection(String selection) {
+  if (selection == null) return null;
+
+  var coordinates = selection.split(":");
+  if (coordinates.length != 2) {
+    throw new FormatException(
+        'Selection should be a colon-separated pair of integers, "123:45".');
+  }
+
+  return coordinates.map((coord) => coord.trim()).map(int.parse).toList();
+}
+
+/// Reads input from stdin until it's closed, and the formats it.
+void formatStdin(FormatterOptions options, List<int> selection) {
+  var selectionStart = 0;
+  var selectionLength = 0;
+
+  if (selection != null) {
+    selectionStart = selection[0];
+    selectionLength = selection[1];
+  }
+
+  var input = new StringBuffer();
+  stdin.transform(new Utf8Decoder()).listen(input.write, onDone: () {
+    var formatter = new DartFormatter(pageWidth: options.pageWidth);
+    try {
+      var source = new SourceCode(input.toString(),
+          uri: "stdin",
+          selectionStart: selectionStart,
+          selectionLength: selectionLength);
+      var output = formatter.formatSource(source);
+      options.reporter
+          .showFile(null, "<stdin>", output, changed: source != output);
+      return true;
+    } on FormatterException catch (err) {
+      stderr.writeln(err.message());
+      exitCode = 65; // sysexits.h: EX_DATAERR
+    } catch (err, stack) {
+      stderr.writeln('''Hit a bug in the formatter when formatting stdin.
+Please report at: github.com/dart-lang/dart_style/issues
+$err
+$stack''');
+      exitCode = 70; // sysexits.h: EX_SOFTWARE
+    }
+  });
+}
+
+/// Formats all of the files and directories given by [paths].
+void formatPaths(FormatterOptions options, List<String> paths) {
+  for (var path in paths) {
+    var directory = new Directory(path);
+    if (directory.existsSync()) {
+      if (!processDirectory(options, directory)) {
+        exitCode = 65;
+      }
+      continue;
+    }
+
+    var file = new File(path);
+    if (file.existsSync()) {
+      if (!processFile(options, file)) {
+        exitCode = 65;
+      }
+    } else {
+      stderr.writeln('No file or directory found at "$path".');
+    }
+  }
+}
+
+/// Prints [error] and usage help then exits with exit code 64.
+void usageError(ArgParser parser, String error) {
+  printUsage(parser, error);
+  exit(64);
+}
+
+void printUsage(ArgParser parser, [String error]) {
+  var output = stdout;
+
+  var message = "Reformats whitespace in Dart source files.";
+  if (error != null) {
+    message = error;
+    output = stdout;
+  }
+
+  output.write("""$message
+
+Usage: dartfmt [-n|-w] [files or directories...]
+
+${parser.usage}
+""");
+}