Gracefully handle pubspecs with dependencies using unknown sources.

sdk/lib/_internal/pub/test/install/unknown_source_test.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS d.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 d.file.
+
+library pub_tests;
+
+import 'dart:io';
+import 'dart:json' as json;
+
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+
+main() {
+  initConfig();
+  integration('fails gracefully on a dependency from an unknown source', () {
+    d.appDir([{"bad": "foo"}]).create();
+
+    schedulePub(args: ['install'],
+        error: new RegExp("Package 'myapp' depends on 'foo' from unknown "
+                          "source 'bad'.\$"),
+        exitCode: 1);
+  });
+
+  integration('fails gracefully on transitive dependency from an unknown '
+              'source', () {
+    d.dir('foo', [
+      d.libDir('foo', 'foo 0.0.1'),
+      d.libPubspec('foo', '0.0.1', deps: [{"bad": "bar"}])
+    ]).create();
+
+    d.appDir([{"path": "../foo"}]).create();
+
+    schedulePub(args: ['install'],
+        error: new RegExp("Package 'foo' depends on 'bar' from unknown "
+                          "source 'bad'.\$"),
+        exitCode: 1);
+  });
+
+  integration('ignores unknown source in lockfile', () {
+    d.dir('foo', [
+      d.libDir('foo'),
+      d.libPubspec('foo', '0.0.1')
+    ]).create();
+
+    // Depend on "foo" from a valid source.
+    d.dir(appPath, [
+      d.pubspec({
+        "name": "myapp",
+        "dependencies": {
+          "foo": {"path": "../foo"}
+        }
+      })
+    ]).create();
+
+    // But lock it to a bad one.
+    d.dir(appPath, [
+      d.file("pubspec.lock", json.stringify({
+        'packages': {
+          'foo': {
+            'version': '0.0.0',
+            'source': 'bad',
+            'description': {
+              'name': 'foo'
+            }
+          }
+        }
+      }))
+    ]).create();
+
+    schedulePub(args: ['install'],
+        output: new RegExp(r"Dependencies installed!$"));
+
+    // Should update to the new one.
+    d.dir(packagesPath, [
+      d.dir("foo", [
+        d.file("foo.dart", 'main() => "foo";')
+      ])
+    ]).validate();
+  });
+}