move deferred_library_check functionality to a library

bin/deferred_library_check.dart

Index: bin/deferred_library_check.dart
diff --git a/bin/deferred_library_check.dart b/bin/deferred_library_check.dart
index 0c092c5c5a2f537a50e82f29ee4174ec9dd36e6c..d9cd15115b6be8f7ed538a7a884efd98e1fff0d8 100644
--- a/bin/deferred_library_check.dart
+++ b/bin/deferred_library_check.dart
@@ -40,7 +40,7 @@ import 'dart:convert';
 import 'dart:io';
 
 import 'package:dart2js_info/info.dart';
-import 'package:quiver/collection.dart';
+import 'package:dart2js_info/deferred_library_check.dart';
 import 'package:yaml/yaml.dart';
 
 Future main(List<String> args) async {
@@ -51,81 +51,9 @@ Future main(List<String> args) async {
   var info = await infoFromFile(args[0]);
   var manifest = await manifestFromFile(args[1]);
 
-  // For each part in the manifest, record the expected "packages" for that
-  // part.
-  var packages = <String, String>{};
-  for (var part in manifest.keys) {
-    for (var package in manifest[part]['packages']) {
-      if (packages.containsKey(package)) {
-        print('You cannot specify that package "$package" maps to both parts '
-            '"$part" and "${packages[package]}".');
-        exit(1);
-      }
-      packages[package] = part;
-    }
-  }
-
-  var guessedPartMapping = new BiMap<String, String>();
-  guessedPartMapping['main'] = 'main';
-
-  bool anyFailed = false;
-
-  checkInfo(BasicInfo info) {
-    var lib = getLibraryOf(info);
-    if (lib != null && isPackageUri(lib.uri)) {
-      var packageName = getPackageName(lib.uri);
-      var outputUnitName = info.outputUnit.name;
-      var expectedPart;
-      if (packages.containsKey(packageName)) {
-        expectedPart = packages[packageName];
-      } else {
-        expectedPart = 'main';
-      }
-      var expectedOutputUnit = guessedPartMapping[expectedPart];
-      if (expectedOutputUnit == null) {
-        guessedPartMapping[expectedPart] = outputUnitName;
-      } else {
-        if (expectedOutputUnit != outputUnitName) {
-          // TODO(het): add options for how to treat unspecified packages
-          if (!packages.containsKey(packageName)) {
-            print('"${info.name}" from package "$packageName" was not declared '
-                'to be in an explicit part but was not in the main part');
-          } else {
-            var actualPart = guessedPartMapping.inverse[outputUnitName];
-            print('"${info.name}" from package "$packageName" was specified to '
-                'be in part $expectedPart but is in part $actualPart');
-          }
-          anyFailed = true;
-        }
-      }
-    }
-  }
-
-  info.functions.forEach(checkInfo);
-  info.fields.forEach(checkInfo);
-  if (anyFailed) {
-    print('The dart2js output did not meet the specification.');
-  } else {
-    print('The dart2js output meets the specification');
-  }
-}
-
-LibraryInfo getLibraryOf(Info info) {
-  var current = info;
-  while (current is! LibraryInfo) {
-    if (current == null) {
-      return null;
-    }
-    current = current.parent;
-  }
-  return current;
-}
-
-bool isPackageUri(Uri uri) => uri.scheme == 'package';
-
-String getPackageName(Uri uri) {
-  assert(isPackageUri(uri));
-  return uri.pathSegments.first;
+  var failures = checkDeferredLibraryManifest(info, manifest);
+  failures.forEach(print);
+  if (failures.isNotEmpty) exitCode = 1;
 }
 
 Future<AllInfo> infoFromFile(String fileName) async {