Support JSON output for pub build.

sdk/lib/_internal/pub/test/test_pub.dart

 // Copyright (c) 2013, 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.
 
 /// Test infrastructure for testing pub. Unlike typical unit tests, most pub
 /// tests are integration tests that stage some stuff on the file system, run
 /// pub, and then validate the results. This library provides an API to build
 /// tests like that.
 library test_pub;
 
@@ skipping 363 matching lines @@
   schedule(
       () => createSymlink(
           path.join(sandboxDir, target),
           path.join(sandboxDir, symlink)),
       'symlinking $target to $symlink');
 }
 
 /// Schedules a call to the Pub command-line utility.
 ///
 /// Runs Pub with [args] and validates that its results match [output] (or
-/// [outputJson]), [error], and [exitCode]. If [outputJson] is given, validates
-/// that pub outputs stringified JSON matching that object.
+/// [outputJson]), [error], and [exitCode].
+///
+/// If [outputJson] is given, validates that pub outputs stringified JSON
+/// matching that object, which can be a literal JSON object or any other
+/// [Matcher].
 void schedulePub({List args, Pattern output, Pattern error, outputJson,
     Future<Uri> tokenEndpoint, int exitCode: exit_codes.SUCCESS}) {
   // Cannot pass both output and outputJson.
   assert(output == null || outputJson == null);
 
   var pub = startPub(args: args, tokenEndpoint: tokenEndpoint);
   pub.shouldExit(exitCode);
 
   var failures = [];
   var stderr;
@@ skipping 409 matching lines @@
 
   // If any lines mismatched, show the expected and actual.
   if (failed) {
     failures.add('Expected $pipe:');
     failures.addAll(expected.map((line) => '| $line'));
     failures.add('Got:');
     failures.addAll(results);
   }
 }
 
+/// Validates that [actualText] is a string of JSON that matches [expected],
+/// which may be a literal JSON object, or any other [Matcher].
 void _validateOutputJson(List<String> failures, String pipe,
                          expected, String actualText) {
   var actual;
   try {
     actual = JSON.decode(actualText);
   } on FormatException catch(error) {
     failures.add('Expected $pipe JSON:');
     failures.add(expected);
     failures.add('Got invalid JSON:');
     failures.add(actualText);
   }
 
-  // Do a deep comparison of the JSON objects.
-  expect(actual, equals(expected));
+  // Match against the expectation.
+  expect(actual, expected);
 }
 
 /// A function that creates a [Validator] subclass.
 typedef Validator ValidatorCreator(Entrypoint entrypoint);
 
 /// Schedules a single [Validator] to run on the [appPath]. Returns a scheduled
 /// Future that contains the errors and warnings produced by that validator.
 Future<Pair<List<String>, List<String>>> schedulePackageValidation(
     ValidatorCreator fn) {
   return schedule(() {
@@ skipping 24 matching lines @@
         _lastMatcher.matches(item.last, matchState);
   }
 
   Description describe(Description description) {
     return description.addAll("(", ", ", ")", [_firstMatcher, _lastMatcher]);
   }
 }
 
 /// A [StreamMatcher] that matches multiple lines of output.
 StreamMatcher emitsLines(String output) => inOrder(output.split("\n"));