Support test fixtures in sh package

Restructures the sh package test setup code to create FixturePreparer
instances for setting up a test fixture and converts some tests to
use it.

The goal with this change is not to switch all the sh tests over to
directly using the new model but instead to ensure that the majority of
the sh tests run with the new model, to allow existing tests to easily
switch to the new model when needed and to allow dependent packages to
be switched to the new model.

Bug: 181070625
Test: m nothing
Change-Id: Ib2c6ac2842d6fafde5663d3ee63c3f934913a00e

2 files changed, 43 insertions, 21 deletions

diff --git a/sh/sh_binary.go b/sh/sh_binary.go
index 031cd4717..49f4961f2 100644
--- a/sh/sh_binary.go
+++ b/sh/sh_binary.go
@@ -40,14 +40,32 @@ var pctx = android.NewPackageContext("android/soong/sh")
 func init() {
 	pctx.Import("android/soong/android")
 
-	android.RegisterModuleType("sh_binary", ShBinaryFactory)
-	android.RegisterModuleType("sh_binary_host", ShBinaryHostFactory)
-	android.RegisterModuleType("sh_test", ShTestFactory)
-	android.RegisterModuleType("sh_test_host", ShTestHostFactory)
+	registerShBuildComponents(android.InitRegistrationContext)
 
 	android.RegisterBp2BuildMutator("sh_binary", ShBinaryBp2Build)
 }
 
+func registerShBuildComponents(ctx android.RegistrationContext) {
+	ctx.RegisterModuleType("sh_binary", ShBinaryFactory)
+	ctx.RegisterModuleType("sh_binary_host", ShBinaryHostFactory)
+	ctx.RegisterModuleType("sh_test", ShTestFactory)
+	ctx.RegisterModuleType("sh_test_host", ShTestHostFactory)
+}
+
+// Test fixture preparer that will register most sh build components.
+//
+// Singletons and mutators should only be added here if they are needed for a majority of sh
+// module types, otherwise they should be added under a separate preparer to allow them to be
+// selected only when needed to reduce test execution time.
+//
+// Module types do not have much of an overhead unless they are used so this should include as many
+// module types as possible. The exceptions are those module types that require mutators and/or
+// singletons in order to function in which case they should be kept together in a separate
+// preparer.
+var PrepareForTestWithShBuildComponents = android.GroupFixturePreparers(
+	android.FixtureRegisterWithContext(registerShBuildComponents),
+)
+
 type shBinaryProperties struct {
 	// Source file of this prebuilt.
 	Src *string `android:"path,arch_variant"`
diff --git a/sh/sh_binary_test.go b/sh/sh_binary_test.go
index f48f7fb29..7a24168e5 100644
--- a/sh/sh_binary_test.go
+++ b/sh/sh_binary_test.go
@@ -37,28 +37,32 @@ func TestMain(m *testing.M) {
 	os.Exit(run())
 }
 
-func testShBinary(t *testing.T, bp string) (*android.TestContext, android.Config) {
-	fs := map[string][]byte{
+var shFixtureFactory = android.NewFixtureFactory(
+	&buildDir,
+	cc.PrepareForTestWithCcBuildComponents,
+	PrepareForTestWithShBuildComponents,
+	android.FixtureMergeMockFs(android.MockFS{
 		"test.sh":            nil,
 		"testdata/data1":     nil,
 		"testdata/sub/data2": nil,
-	}
-
-	config := android.TestArchConfig(buildDir, nil, bp, fs)
-
-	ctx := android.NewTestArchContext(config)
-	ctx.RegisterModuleType("sh_test", ShTestFactory)
-	ctx.RegisterModuleType("sh_test_host", ShTestHostFactory)
-
-	cc.RegisterRequiredBuildComponentsForTest(ctx)
+	}),
+)
 
-	ctx.Register()
-	_, errs := ctx.ParseFileList(".", []string{"Android.bp"})
-	android.FailIfErrored(t, errs)
-	_, errs = ctx.PrepareBuildActions(config)
-	android.FailIfErrored(t, errs)
+// testShBinary runs tests using the shFixtureFactory
+//
+// Do not add any new usages of this, instead use the shFixtureFactory directly as it makes it much
+// easier to customize the test behavior.
+//
+// If it is necessary to customize the behavior of an existing test that uses this then please first
+// convert the test to using shFixtureFactory first and then in a following change add the
+// appropriate fixture preparers. Keeping the conversion change separate makes it easy to verify
+// that it did not change the test behavior unexpectedly.
+//
+// deprecated
+func testShBinary(t *testing.T, bp string) (*android.TestContext, android.Config) {
+	result := shFixtureFactory.RunTestWithBp(t, bp)
 
-	return ctx, config
+	return result.TestContext, result.Config
 }
 
 func TestShTestSubDir(t *testing.T) {