Add unit tests for android/neverallow.go

Bug: 74506774
Test: lunch aosp_walleye-userdebug && make  # runs unit tests
Change-Id: Ibde685d7213713be219681cb039ad58a43d9c377
diff --git a/android/neverallow_test.go b/android/neverallow_test.go
new file mode 100644
index 0000000..19eeb22
--- /dev/null
+++ b/android/neverallow_test.go
@@ -0,0 +1,195 @@
+// 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 android
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+var neverallowTests = []struct {
+	name          string
+	fs            map[string][]byte
+	expectedError string
+}{
+	{
+		name: "no vndk.enabled under vendor directory",
+		fs: map[string][]byte{
+			"vendor/Blueprints": []byte(`
+				cc_library {
+					name: "libvndk",
+					vendor_available: true,
+					vndk: {
+						enabled: true,
+					},
+				}`),
+		},
+		expectedError: "VNDK can never contain a library that is device dependent",
+	},
+	{
+		name: "no vndk.enabled under device directory",
+		fs: map[string][]byte{
+			"device/Blueprints": []byte(`
+				cc_library {
+					name: "libvndk",
+					vendor_available: true,
+					vndk: {
+						enabled: true,
+					},
+				}`),
+		},
+		expectedError: "VNDK can never contain a library that is device dependent",
+	},
+
+	{
+		name: "no enforce_vintf_manifest.cflags",
+		fs: map[string][]byte{
+			"Blueprints": []byte(`
+				cc_library {
+					name: "libexample",
+					product_variables: {
+						enforce_vintf_manifest: {
+							cflags: ["-DSHOULD_NOT_EXIST"],
+						},
+					},
+				}`),
+		},
+		expectedError: "manifest enforcement should be independent",
+	},
+	{
+		name: "libhidltransport enforce_vintf_manifest.cflags",
+		fs: map[string][]byte{
+			"Blueprints": []byte(`
+				cc_library {
+					name: "libhidltransport",
+					product_variables: {
+						enforce_vintf_manifest: {
+							cflags: ["-DSHOULD_NOT_EXIST"],
+						},
+					},
+				}`),
+		},
+		expectedError: "",
+	},
+
+	{
+		name: "no treble_linker_namespaces.cflags",
+		fs: map[string][]byte{
+			"Blueprints": []byte(`
+				cc_library {
+					name: "libexample",
+					product_variables: {
+						treble_linker_namespaces: {
+							cflags: ["-DSHOULD_NOT_EXIST"],
+						},
+					},
+				}`),
+		},
+		expectedError: "nothing should care if linker namespaces are enabled or not",
+	},
+	{
+		name: "libc_bionic_ndk treble_linker_namespaces.cflags",
+		fs: map[string][]byte{
+			"Blueprints": []byte(`
+				cc_library {
+					name: "libc_bionic_ndk",
+					product_variables: {
+						treble_linker_namespaces: {
+							cflags: ["-DSHOULD_NOT_EXIST"],
+						},
+					},
+				}`),
+		},
+		expectedError: "",
+	},
+}
+
+func TestNeverallow(t *testing.T) {
+	buildDir, err := ioutil.TempDir("", "soong_neverallow_test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(buildDir)
+
+	config := TestConfig(buildDir, nil)
+
+	for _, test := range neverallowTests {
+		t.Run(test.name, func(t *testing.T) {
+			_, errs := testNeverallow(t, config, test.fs)
+
+			if test.expectedError == "" {
+				FailIfErrored(t, errs)
+			} else {
+				FailIfNoMatchingErrors(t, test.expectedError, errs)
+			}
+		})
+	}
+}
+
+func testNeverallow(t *testing.T, config Config, fs map[string][]byte) (*TestContext, []error) {
+	ctx := NewTestContext()
+	ctx.RegisterModuleType("cc_library", ModuleFactoryAdaptor(newMockCcLibraryModule))
+	ctx.PostDepsMutators(registerNeverallowMutator)
+	ctx.Register()
+
+	ctx.MockFileSystem(fs)
+
+	_, errs := ctx.ParseBlueprintsFiles("Blueprints")
+	if len(errs) > 0 {
+		return ctx, errs
+	}
+
+	_, errs = ctx.PrepareBuildActions(config)
+	return ctx, errs
+}
+
+type mockProperties struct {
+	Vendor_available *bool
+
+	Vndk struct {
+		Enabled                *bool
+		Support_system_process *bool
+		Extends                *string
+	}
+
+	Product_variables struct {
+		Enforce_vintf_manifest struct {
+			Cflags []string
+		}
+
+		Treble_linker_namespaces struct {
+			Cflags []string
+		}
+	}
+}
+
+type mockCcLibraryModule struct {
+	ModuleBase
+	properties mockProperties
+}
+
+func newMockCcLibraryModule() Module {
+	m := &mockCcLibraryModule{}
+	m.AddProperties(&m.properties)
+	InitAndroidModule(m)
+	return m
+}
+
+func (p *mockCcLibraryModule) DepsMutator(ctx BottomUpMutatorContext) {
+}
+
+func (p *mockCcLibraryModule) GenerateAndroidBuildActions(ModuleContext) {
+}