Expose aggregate transformers in barback.

pkg/barback/test/package_graph/transform/declaring_aggregate_test.dart

Index: pkg/barback/test/package_graph/transform/declaring_aggregate_test.dart
diff --git a/pkg/barback/test/package_graph/transform/declaring_aggregate_test.dart b/pkg/barback/test/package_graph/transform/declaring_aggregate_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..7c8e982ca672de7b15fb6eae80419115b789a0dd
--- /dev/null
+++ b/pkg/barback/test/package_graph/transform/declaring_aggregate_test.dart
@@ -0,0 +1,248 @@
+// Copyright (c) 2014, 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.
+
+library barback.test.package_graph.transform.declaring_aggregate_test;
+
+import 'package:barback/src/utils.dart';
+import 'package:scheduled_test/scheduled_test.dart';
+
+import '../../utils.dart';
+
+main() {
+  initConfig();
+  group("a declaring aggregate transformer", () {
+    test("is eager by default", () {
+      var transformer = new DeclaringAggregateManyToOneTransformer(
+          "txt", "out.txt");
+      initGraph(["app|foo.txt"], {"app": [[transformer]]});
+
+      updateSources(["app|foo.txt"]);
+      buildShouldSucceed();
+
+      expect(transformer.numRuns, completion(equals(1)));
+    });
+
+    test("is deferred if any primary input is deferred", () {
+      var rewrite = new LazyRewriteTransformer("in", "txt");
+      var aggregate = new DeclaringAggregateManyToOneTransformer(
+          "txt", "out.txt");
+      initGraph(["app|foo.in", "app|bar.txt", "app|baz.txt"], {"app": [
+        [rewrite]
+      ]});
+
+      updateSources(["app|foo.in", "app|bar.txt", "app|baz.txt"]);
+      buildShouldSucceed();
+
+      // Add [aggregate] to the graph after a build has been completed so that
+      // all its inputs are available immediately. Otherwise it could start
+      // applying eagerly before receiving its lazy input.
+      updateTransformers("app", [[rewrite], [aggregate]]);
+      buildShouldSucceed();
+      expect(aggregate.numRuns, completion(equals(0)));
+
+      expectAsset("app|out.txt", "bar\nbaz\nfoo.txt");
+      buildShouldSucceed();
+      expect(aggregate.numRuns, completion(equals(1)));
+    });
+
+    test("switches from eager to deferred if a deferred primary input is added",
+        () {
+      var transformer = new DeclaringAggregateManyToOneTransformer(
+          "txt", "out.txt");
+      initGraph(["app|foo.in", "app|bar.txt", "app|baz.txt"], {"app": [
+        [new LazyRewriteTransformer("in", "txt")],
+        [transformer]
+      ]});
+
+      updateSources(["app|bar.txt", "app|baz.txt"]);
+      buildShouldSucceed();
+      expect(transformer.numRuns, completion(equals(1)));
+
+      updateSources(["app|foo.in"]);
+      buildShouldSucceed();
+      expect(transformer.numRuns, completion(equals(1)));
+
+      expectAsset("app|out.txt", "bar\nbaz\nfoo.txt");
+      buildShouldSucceed();
+      expect(transformer.numRuns, completion(equals(2)));
+    });
+
+    test("switches from deferred to eager if its last deferred primary input "
+        "is removed", () {
+      var rewrite = new LazyRewriteTransformer("in", "txt");
+      var aggregate = new DeclaringAggregateManyToOneTransformer(
+          "txt", "out.txt");
+      initGraph(["app|foo.in", "app|bar.txt", "app|baz.txt"], {"app": [
+        [rewrite]
+      ]});
+
+      updateSources(["app|foo.in", "app|bar.txt", "app|baz.txt"]);
+      buildShouldSucceed();
+
+      // Add [aggregate] to the graph after a build has been completed so that
+      // all its inputs are available immediately. Otherwise it could start
+      // applying eagerly before receiving its lazy input.
+      updateTransformers("app", [[rewrite], [aggregate]]);
+      buildShouldSucceed();
+      expect(aggregate.numRuns, completion(equals(0)));
+
+      removeSources(["app|foo.in"]);
+      buildShouldSucceed();
+      expect(aggregate.numRuns, completion(equals(1)));
+    });
+
+    test("begins running eagerly when all its deferred primary inputs become "
+        "available", () {
+      var lazyPhase = [
+        new LazyAssetsTransformer(["app|foo.txt", "app|foo.x"],
+            input: "app|foo.in"),
+        new LazyAssetsTransformer(["app|bar.txt", "app|bar.x"],
+            input: "app|bar.in")
+      ];
+      var transformer = new DeclaringAggregateManyToOneTransformer(
+          "txt", "out.txt");
+      initGraph(["app|foo.in", "app|bar.in", "app|baz.txt"], {"app": [
+        lazyPhase,
+      ]});
+
+      updateSources(["app|foo.in", "app|bar.in", "app|baz.txt"]);
+      buildShouldSucceed();
+
+      // Add [transformer] to the graph after a build has been completed so that
+      // all its inputs are available immediately. Otherwise it could start
+      // applying eagerly before receiving its lazy inputs.
+      updateTransformers("app", [lazyPhase, [transformer]]);
+      buildShouldSucceed();
+      expect(transformer.numRuns, completion(equals(0)));
+
+      // Now "app|foo.txt" will be available, but "app|bar.txt" won't, so the
+      // [transformer] shouldn't run.
+      expectAsset("app|foo.x", "app|foo.x");
+      buildShouldSucceed();
+      expect(transformer.numRuns, completion(equals(0)));
+
+      // Now "app|foo.txt" and "app|bar.txt" will both be available, so the
+      // [transformer] should run.
+      expectAsset("app|bar.x", "app|bar.x");
+      buildShouldSucceed();
+      expect(transformer.numRuns, completion(equals(1)));
+    });
+
+    test("stops running eagerly when any of its deferred primary inputs become "
+        "unavailable", () {
+      var lazyPhase = [
+        new LazyAssetsTransformer(["app|foo.txt", "app|foo.x"],
+            input: "app|foo.in"),
+        new LazyAssetsTransformer(["app|bar.txt", "app|bar.x"],
+            input: "app|bar.in")
+      ];
+      var transformer = new DeclaringAggregateManyToOneTransformer(
+          "txt", "out.txt");
+      initGraph(["app|foo.in", "app|bar.in", "app|baz.txt"], {"app": [
+        lazyPhase
+      ]});
+
+      updateSources(["app|foo.in", "app|bar.in", "app|baz.txt"]);
+      expectAsset("app|foo.x", "app|foo.x");
+      expectAsset("app|bar.x", "app|bar.x");
+      buildShouldSucceed();
+
+
+      // Add [transformer] to the graph after a build has been completed so that
+      // all its inputs are available immediately. Otherwise it could start
+      // applying eagerly before receiving its lazy inputs.
+      updateTransformers("app", [lazyPhase, [transformer]]);
+      buildShouldSucceed();
+      expect(transformer.numRuns, completion(equals(1)));
+
+      // Now "app|foo.txt" is unavailable, so the [transformer] shouldn't run.
+      updateSources(["app|foo.in"]);
+      buildShouldSucceed();
+      expect(transformer.numRuns, completion(equals(1)));
+    });
+
+    test("re-declares its outputs for a new primary input", () {
+      initGraph(["app|foo.in", "app|bar.txt", "app|baz.txt"], {"app": [
+        [new LazyRewriteTransformer("in", "txt")],
+        [new DeclaringAggregateManyToManyTransformer("txt")]
+      ]});
+
+      updateSources(["app|foo.in", "app|bar.txt"]);
+      buildShouldSucceed();
+
+      updateSources(["app|baz.txt"]);
+      buildShouldSucceed();
+      expectAsset("app|baz.txt", "modified baz");

[Bob Nystrom, 2014/05/27 17:20:18]

How does this test that the outputs are re-declared, and not just re-applied?

[nweiz, 2014/05/27 21:03:10]

Since one of its inputs is deferred, it's deferred. If it didn't re-declare the
outputs here, "baz.txt" wouldn't be declared as an output at all, and this
request would fail.

[Bob Nystrom, 2014/05/28 21:03:58]

Ah, so this relies on requests for undeclared outputs not triggering a build.
But if, for some reason, that transformer got tickled into running, baz.txt
would appear as an output, right?

How about a little comment explaining this?

[nweiz, 2014/05/28 23:32:12]

Done.

+    });
+
+    test("re-declares its outputs for a new primary input received while "
+        "applying", () {
+      var transformer = new DeclaringAggregateManyToManyTransformer("txt");
+      initGraph(["app|foo.in", "app|bar.txt", "app|baz.txt"], {"app": [
+        [new LazyRewriteTransformer("in", "txt")],
+        [transformer]
+      ]});
+
+      transformer.pauseApply();
+      updateSources(["app|foo.in", "app|bar.txt"]);
+
+      // Ensure we're waiting on `apply()`.
+      schedule(pumpEventQueue);
+
+      updateSources(["app|baz.txt"]);
+      transformer.resumeApply();
+      buildShouldSucceed();
+
+      expectAsset("app|baz.txt", "modified baz");
+    });
+
+    test("re-declares its outputs for a new primary input received while "
+        "applying after a primary input was modified", () {
+      var transformer = new DeclaringAggregateManyToManyTransformer("txt");
+      initGraph(["app|foo.in", "app|bar.txt", "app|baz.txt"], {"app": [
+        [new LazyRewriteTransformer("in", "txt")],
+        [transformer]
+      ]});
+
+      transformer.pauseApply();
+      updateSources(["app|foo.in", "app|bar.txt"]);
+
+      // Ensure we're waiting on `apply()`.
+      schedule(pumpEventQueue);
+
+      updateSources(["app|bar.txt"]);
+
+      // Make sure the change to "bar.txt" is fully processed.
+      schedule(pumpEventQueue);
+
+      updateSources(["app|baz.txt"]);
+      transformer.resumeApply();
+      buildShouldSucceed();
+
+      expectAsset("app|baz.txt", "modified baz");
+    });
+  });
+
+  group("a lazy aggregate transformer", () {
+    test("doesn't run eagerly", () {
+      var transformer = new LazyAggregateManyToOneTransformer("txt", "out.txt");
+      initGraph(["app|foo.txt"], {"app": [[transformer]]});
+
+      updateSources(["app|foo.txt"]);
+      buildShouldSucceed();
+
+      expect(transformer.numRuns, completion(equals(0)));
+    });
+
+    test("runs when an output is requested", () {
+      initGraph(["app|foo.txt"], {"app": [[
+        new LazyAggregateManyToOneTransformer("txt", "out.txt")
+      ]]});
+
+      updateSources(["app|foo.txt"]);
+      buildShouldSucceed();
+      expectAsset("app|out.txt", "foo");
+    });
+  });
+}