From 8d1595b992e92ed42a22de10bfd68ac488e60f58 Mon Sep 17 00:00:00 2001
From: Daniel Mikusa <dmikusa@vmware.com>
Date: Fri, 19 Aug 2022 14:17:32 -0400
Subject: [PATCH] Streamline test setup

This is an optional PR, checking to see what folks think.

This PR reduces the boilerplate code with test setup. It uses Go test's `TempDir` method to make temp directories. These are automatically cleaned up, so we don't have to deal with defer and clean up methods. The PR also stores the test object, so it's not necessary to pass around via method arguments.

Signed-off-by: Daniel Mikusa <dmikusa@vmware.com>
---
 profile/build_test.go  | 43 ++++++++++++++++++------------------------
 profile/detect_test.go | 29 +++++++++++-----------------
 2 files changed, 29 insertions(+), 43 deletions(-)

diff --git a/profile/build_test.go b/profile/build_test.go
index 3cdcfc4..97b260a 100644
--- a/profile/build_test.go
+++ b/profile/build_test.go
@@ -22,7 +22,6 @@ import (
 	"testing"
 
 	. "github.com/onsi/gomega"
-	"github.com/onsi/gomega/types"
 
 	"github.com/buildpacks/profile/profile"
 
@@ -30,28 +29,33 @@ import (
 )
 
 type BuildTest struct {
+	test    *testing.T
 	context libcnb.BuildContext
-	expect  func(actual interface{}, extra ...interface{}) types.Assertion
+	expect  ExpectFunc
 }
 
-func (b BuildTest) SetupGomega(t *testing.T) BuildTest {
-	b.expect = NewGomegaWithT(t).Expect
-	return b
+func NewBuildTestBuilder(t *testing.T) BuildTest {
+	return BuildTest{
+		test:   t,
+		expect: NewGomegaWithT(t).Expect,
+	}
 }
 
 func (b BuildTest) SetupWorkspace() BuildTest {
 	var err error
+
 	b.context.Buildpack.Path = "../"
-	b.context.ApplicationPath, err = os.MkdirTemp("", "profile")
-	b.expect(err).NotTo(HaveOccurred())
-	profilePath := filepath.Join(b.context.ApplicationPath, ".profile")
+	b.context.ApplicationPath = b.test.TempDir()
+	b.context.Layers.Path = b.test.TempDir()
+
+	err = os.MkdirAll(b.context.Layers.Path, os.ModePerm)
+	b.expect(err).ToNot(HaveOccurred())
 
+	profilePath := filepath.Join(b.context.ApplicationPath, ".profile")
 	f, err := os.Create(profilePath)
 	b.expect(err).NotTo(HaveOccurred())
 	defer f.Close()
 
-	b.expect(err).To(BeNil())
-
 	_, err = f.WriteString(
 		`
 echo "Hello world"
@@ -64,24 +68,13 @@ export HELLO
 	return b
 }
 
-func (b BuildTest) RemoveWorkspace() BuildTest {
-	b.expect(os.RemoveAll(b.context.ApplicationPath)).To(Succeed())
-	return b
-}
-
-func (b BuildTest) Build() (libcnb.BuildContext, ExpectFunc, AfterFunc) {
-	outputPath, _ := os.MkdirTemp("", "dotprofile_out")
-	os.MkdirAll(outputPath, os.ModePerm)
-	b.context.Layers.Path = outputPath
-	return b.context, b.expect, func() {
-		b.RemoveWorkspace()
-		os.RemoveAll(outputPath)
-	}
+func (b BuildTest) Build() (libcnb.BuildContext, ExpectFunc) {
+	return b.context, b.expect
 }
 
 func TestBuildExecutes(t *testing.T) {
-	ctx, Expect, After := BuildTest{}.SetupGomega(t).SetupWorkspace().Build()
-	defer After()
+	ctx, Expect := NewBuildTestBuilder(t).SetupWorkspace().Build()
+
 	Expect(profile.Build(ctx)).To(Equal(libcnb.BuildResult{
 		Layers: []libcnb.Layer{{
 			LayerTypes: libcnb.LayerTypes{
diff --git a/profile/detect_test.go b/profile/detect_test.go
index d50ae7e..45af5b1 100644
--- a/profile/detect_test.go
+++ b/profile/detect_test.go
@@ -30,44 +30,37 @@ import (
 )
 
 type ExpectFunc func(actual interface{}, extra ...interface{}) types.Assertion
-type AfterFunc func()
 
 type DetectTest struct {
+	test    *testing.T
 	context libcnb.DetectContext
 	expect  ExpectFunc
 }
 
-func (d DetectTest) SetupGomega(t *testing.T) DetectTest {
-	d.expect = NewGomegaWithT(t).Expect
-	return d
+func NewDetectTestBuilder(t *testing.T) DetectTest {
+	return DetectTest{
+		test:   t,
+		expect: NewGomegaWithT(t).Expect,
+	}
 }
 
 func (d DetectTest) SetupWorkspace() DetectTest {
-	var err error
-	d.context.ApplicationPath, err = os.MkdirTemp("", "profile")
-	d.expect(err).NotTo(HaveOccurred())
-	return d
-}
-
-func (d DetectTest) RemoveWorkspace() DetectTest {
-	d.expect(os.RemoveAll(d.context.ApplicationPath)).To(Succeed())
+	d.context.ApplicationPath = d.test.TempDir()
 	return d
 }
 
-func (d DetectTest) Build() (libcnb.DetectContext, ExpectFunc, AfterFunc) {
-	return d.context, d.expect, func() { d.RemoveWorkspace() }
+func (d DetectTest) Build() (libcnb.DetectContext, ExpectFunc) {
+	return d.context, d.expect
 }
 
 func TestDetectFailsWithoutProfileScript(t *testing.T) {
-	ctx, Expect, After := DetectTest{}.SetupGomega(t).SetupWorkspace().Build()
-	defer After()
+	ctx, Expect := NewDetectTestBuilder(t).SetupWorkspace().Build()
 
 	Expect(profile.Detect(ctx)).To(Equal(libcnb.DetectResult{}))
 }
 
 func TestDetectPassesWithProfileScript(t *testing.T) {
-	ctx, Expect, After := DetectTest{}.SetupGomega(t).SetupWorkspace().Build()
-	defer After()
+	ctx, Expect := NewDetectTestBuilder(t).SetupWorkspace().Build()
 
 	Expect(os.WriteFile(filepath.Join(ctx.ApplicationPath, ".profile"), []byte(`echo "Hello World!"`), 0600))