Add dexpreopt enabled tests

Add tests that verify when dexpreopt is enabled or disabled.

Test: dexpreopt_test.go
Change-Id: Ideba9c0dac30eb31e7ae29e46d1d1590202b8369
diff --git a/java/dexpreopt_test.go b/java/dexpreopt_test.go
new file mode 100644
index 0000000..5b55799
--- /dev/null
+++ b/java/dexpreopt_test.go
@@ -0,0 +1,126 @@
+// Copyright 2018 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package java
+
+import (
+	"testing"
+)
+
+func TestDexpreoptEnabled(t *testing.T) {
+	tests := []struct {
+		name    string
+		bp      string
+		enabled bool
+	}{
+		{
+			name: "app",
+			bp: `
+				android_app {
+					name: "foo",
+					srcs: ["a.java"],
+				}`,
+			enabled: true,
+		},
+		{
+			name: "installable java library",
+			bp: `
+				java_library {
+					name: "foo",
+					installable: true,
+					srcs: ["a.java"],
+				}`,
+			enabled: true,
+		},
+		{
+			name: "java binary",
+			bp: `
+				java_binary {
+					name: "foo",
+					srcs: ["a.java"],
+				}`,
+			enabled: true,
+		},
+
+		{
+			name: "app without sources",
+			bp: `
+				android_app {
+					name: "foo",
+				}`,
+			// TODO(ccross): this should probably be false
+			enabled: true,
+		},
+		{
+			name: "installable java library without sources",
+			bp: `
+				java_library {
+					name: "foo",
+					installable: true,
+				}`,
+			// TODO(ccross): this should probably be false
+			enabled: true,
+		},
+
+		{
+			name: "static java library",
+			bp: `
+				java_library {
+					name: "foo",
+					srcs: ["a.java"],
+				}`,
+			enabled: false,
+		},
+		{
+			name: "android test",
+			bp: `
+				android_test {
+					name: "foo",
+					srcs: ["a.java"],
+				}`,
+			enabled: false,
+		},
+		{
+			name: "android test helper app",
+			bp: `
+				android_test_helper_app {
+					name: "foo",
+					srcs: ["a.java"],
+				}`,
+			enabled: false,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			ctx := testJava(t, test.bp)
+
+			dexpreopt := ctx.ModuleForTests("foo", "android_common").MaybeDescription("dexpreopt")
+			enabled := dexpreopt.Rule != nil
+
+			if enabled != test.enabled {
+				t.Fatalf("want dexpreopt %s, got %s", enabledString(test.enabled), enabledString(enabled))
+			}
+		})
+
+	}
+}
+
+func enabledString(enabled bool) string {
+	if enabled {
+		return "enabled"
+	} else {
+		return "disabled"
+	}
+}