Cache snapshots of (mostly) immutable transformer phases.

sdk/lib/_internal/pub_generated/test/transformer/cache_test.dart

+library pub_tests;
+import 'package:scheduled_test/scheduled_test.dart';
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+import '../serve/utils.dart';
+void setUp() {
+  servePackages((builder) {
+    builder.serveRepoPackage('barback');
+    builder.serve("foo", "1.2.3", deps: {
+      'barback': 'any'
+    },
+        contents: [
+            d.dir(
+                "lib",
+                [d.file("transformer.dart", replaceTransformer("Hello", "Goodbye"))])]);
+    builder.serve("bar", "1.2.3", deps: {
+      'barback': 'any'
+    },
+        contents: [
+            d.dir(
+                "lib",
+                [d.file("transformer.dart", replaceTransformer("Goodbye", "See ya"))])]);
+  });
+  d.dir(appPath, [d.pubspec({
+      "name": "myapp",
+      "dependencies": {
+        "foo": "1.2.3",
+        "bar": "1.2.3"
+      },
+      "transformers": ["foo"]
+    }),
+        d.dir("bin", [d.file("myapp.dart", "main() => print('Hello!');")])]).create();
+  pubGet();
+}
+main() {
+  initConfig();
+  integration("caches a transformer snapshot", () {
+    setUp();
+    var process = pubRun(args: ['myapp']);
+    process.stdout.expect("Goodbye!");
+    process.shouldExit();
+    d.dir(
+        appPath,
+        [
+            d.dir(
+                ".pub/transformers",
+                [
+                    d.file("manifest.txt", "0.1.2+3\nfoo"),
+                    d.matcherFile("transformers.snapshot", isNot(isEmpty))])]).validate();
+    process = pubRun(args: ['myapp']);
+    process.stdout.expect("Goodbye!");
+    process.shouldExit();
+  });
+  integration("recaches if the SDK version is out-of-date", () {
+    setUp();
+    d.dir(
+        appPath,
+        [
+            d.dir(
+                ".pub/transformers",
+                [
+                    d.file("manifest.txt", "0.0.1\nfoo"),
+                    d.file("transformers.snapshot", "junk")])]).create();
+    var process = pubRun(args: ['myapp']);
+    process.stdout.expect("Goodbye!");
+    process.shouldExit();
+    d.dir(
+        appPath,
+        [
+            d.dir(
+                ".pub/transformers",
+                [
+                    d.file("manifest.txt", "0.1.2+3\nfoo"),
+                    d.matcherFile("transformers.snapshot", isNot(isEmpty))])]).validate();
+  });
+  integration("recaches if the transformers change", () {
+    setUp();
+    var process = pubRun(args: ['myapp']);
+    process.stdout.expect("Goodbye!");
+    process.shouldExit();
+    d.dir(
+        appPath,
+        [
+            d.dir(
+                ".pub/transformers",
+                [
+                    d.file("manifest.txt", "0.1.2+3\nfoo"),
+                    d.matcherFile("transformers.snapshot", isNot(isEmpty))])]).validate();
+    d.dir(appPath, [d.pubspec({
+        "name": "myapp",
+        "dependencies": {
+          "foo": "1.2.3",
+          "bar": "1.2.3"
+        },
+        "transformers": ["foo", "bar"]
+      }),
+          d.dir("bin", [d.file("myapp.dart", "main() => print('Hello!');")])]).create();
+    process = pubRun(args: ['myapp']);
+    process.stdout.expect("See ya!");
+    process.shouldExit();
+    d.dir(
+        appPath,
+        [
+            d.dir(
+                ".pub/transformers",
+                [
+                    d.file("manifest.txt", "0.1.2+3\nbar,foo"),
+                    d.matcherFile("transformers.snapshot", isNot(isEmpty))])]).validate();
+  });
+  integration("recaches if the transformer version changes", () {
+    setUp();
+    var process = pubRun(args: ['myapp']);
+    process.stdout.expect("Goodbye!");
+    process.shouldExit();
+    d.dir(
+        appPath,
+        [
+            d.dir(
+                ".pub/transformers",
+                [
+                    d.file("manifest.txt", "0.1.2+3\nfoo"),
+                    d.matcherFile("transformers.snapshot", isNot(isEmpty))])]).validate();
+    servePackages((builder) {
+      builder.serve("foo", "2.0.0", deps: {
+        'barback': 'any'
+      },
+          contents: [
+              d.dir(
+                  "lib",
+                  [d.file("transformer.dart", replaceTransformer("Hello", "New"))])]);
+    });
+    d.dir(appPath, [d.pubspec({
+        "name": "myapp",
+        "dependencies": {
+          "foo": "any"
+        },
+        "transformers": ["foo"]
+      })]).create();
+    pubUpgrade();
+    process = pubRun(args: ['myapp']);
+    process.stdout.expect("New!");
+    process.shouldExit();
+    d.dir(
+        appPath,
+        [
+            d.dir(
+                ".pub/transformers",
+                [
+                    d.file("manifest.txt", "0.1.2+3\nfoo"),
+                    d.matcherFile("transformers.snapshot", isNot(isEmpty))])]).validate();
+  });
+}
+String replaceTransformer(String input, String output) {
+  return """
+import 'dart:async';
+
+import 'package:barback/barback.dart';
+
+class ReplaceTransformer extends Transformer {
+  ReplaceTransformer.asPlugin();
+
+  String get allowedExtensions => '.dart';
+
+  Future apply(Transform transform) {
+    return transform.primaryInput.readAsString().then((contents) {
+      transform.addOutput(new Asset.fromString(
+          transform.primaryInput.id,
+          contents.replaceAll("$input", "$output")));
+    });
+  }
+}
+""";
+}