From bee9c4b2553a7f0738413f2fe24363e0df200654 Mon Sep 17 00:00:00 2001
From: Forest Eckhardt <forest.eckhardt@broadcom.com>
Date: Tue, 10 Sep 2024 18:41:20 +0000
Subject: [PATCH] Remove integration test in favor of unit test that excerises
 the same code path

---
 build_test.go                           | 24 +++++++-
 integration/empty_cache_test.go         | 79 -------------------------
 integration/init_test.go                |  1 -
 integration/testdata/no_modules/go.mod  |  3 -
 integration/testdata/no_modules/main.go | 11 ----
 5 files changed, 22 insertions(+), 96 deletions(-)
 delete mode 100644 integration/empty_cache_test.go
 delete mode 100644 integration/testdata/no_modules/go.mod
 delete mode 100644 integration/testdata/no_modules/main.go

diff --git a/build_test.go b/build_test.go
index 9451f2c3..27abe2ab 100644
--- a/build_test.go
+++ b/build_test.go
@@ -54,8 +54,7 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		err = os.MkdirAll(filepath.Join(layersDir, "mod-cache"), os.ModePerm)
 		Expect(err).NotTo(HaveOccurred())
 
-		_, err = os.CreateTemp(filepath.Join(layersDir, "mod-cache"), "example")
-		Expect(err).NotTo(HaveOccurred())
+		Expect(os.WriteFile(filepath.Join(filepath.Join(layersDir, "mod-cache"), "cache"), nil, os.ModePerm))
 
 		now := time.Now()
 		clock = chronos.NewClock(func() time.Time {
@@ -177,6 +176,27 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		})
 	})
 
+	context("when the mod cache layer is empty", func() {
+		it.Before(func() {
+			err := os.RemoveAll(filepath.Join(layersDir, "mod-cache", "cache"))
+			Expect(err).NotTo(HaveOccurred())
+		})
+
+		it("does not include the module cache layer in the build result", func() {
+			result, err := build(packit.BuildContext{
+				Layers:     packit.Layers{Path: layersDir},
+				WorkingDir: workingDir,
+				BuildpackInfo: packit.BuildpackInfo{
+					Name:    "Some Buildpack",
+					Version: "some-version",
+				},
+			})
+			Expect(err).NotTo(HaveOccurred())
+
+			Expect(result.Layers).To(BeEmpty())
+		})
+	})
+
 	context("failure cases", func() {
 		context("build process fails to check if it should run", func() {
 			it.Before(func() {
diff --git a/integration/empty_cache_test.go b/integration/empty_cache_test.go
deleted file mode 100644
index 04d9860f..00000000
--- a/integration/empty_cache_test.go
+++ /dev/null
@@ -1,79 +0,0 @@
-package integration_test
-
-import (
-	"fmt"
-	"os"
-	"path/filepath"
-	"testing"
-
-	"github.com/paketo-buildpacks/occam"
-	"github.com/sclevine/spec"
-
-	. "github.com/onsi/gomega"
-	. "github.com/paketo-buildpacks/occam/matchers"
-)
-
-func testEmptyCache(t *testing.T, context spec.G, it spec.S) {
-	var (
-		Expect = NewWithT(t).Expect
-
-		pack   occam.Pack
-		docker occam.Docker
-	)
-
-	it.Before(func() {
-		pack = occam.NewPack().WithVerbose().WithNoColor()
-		docker = occam.NewDocker()
-	})
-
-	context("when building a simple go mod app", func() {
-		var (
-			image occam.Image
-
-			name   string
-			source string
-		)
-
-		it.Before(func() {
-			var err error
-			name, err = occam.RandomName()
-			Expect(err).NotTo(HaveOccurred())
-		})
-
-		it.After(func() {
-			Expect(docker.Volume.Remove.Execute(occam.CacheVolumeNames(name))).To(Succeed())
-			Expect(docker.Image.Remove.Execute(image.ID)).To(Succeed())
-			Expect(os.RemoveAll(source)).To(Succeed())
-		})
-
-		it("builds successfully", func() {
-			var err error
-			source, err = occam.Source(filepath.Join("testdata", "no_modules"))
-			Expect(err).NotTo(HaveOccurred())
-
-			var logs fmt.Stringer
-			image, logs, err = pack.Build.
-				WithPullPolicy("never").
-				WithBuildpacks(
-					settings.Buildpacks.GoDist.Online,
-					settings.Buildpacks.GoModVendor.Online,
-				).
-				WithEnv(map[string]string{
-					"GOTELEMETRY": "off",
-				}).
-				Execute(name, source)
-			Expect(err).NotTo(HaveOccurred(), logs.String)
-
-			Expect(logs).To(ContainLines(
-				MatchRegexp(fmt.Sprintf(`%s \d+\.\d+\.\d+`, settings.Buildpack.Name)),
-				"  Executing build process",
-				"    Running 'go mod vendor'",
-				"      go: no dependencies to vendor",
-				MatchRegexp(`      Completed in ([0-9]*(\.[0-9]*)?[a-z]+)+`),
-				"",
-			))
-
-			Expect(logs).NotTo(ContainSubstring(fmt.Sprintf("%s:mod-cache", settings.Buildpack.ID)), logs.String)
-		})
-	})
-}
diff --git a/integration/init_test.go b/integration/init_test.go
index 874db9ab..96d16945 100644
--- a/integration/init_test.go
+++ b/integration/init_test.go
@@ -82,7 +82,6 @@ func TestIntegration(t *testing.T) {
 
 	suite := spec.New("Integration", spec.Report(report.Terminal{}), spec.Parallel())
 	suite("Default", testDefault)
-	suite("EmptyCache", testEmptyCache)
 	suite("Vendored", testVendored)
 	suite.Run(t)
 }
diff --git a/integration/testdata/no_modules/go.mod b/integration/testdata/no_modules/go.mod
deleted file mode 100644
index 2c70bc73..00000000
--- a/integration/testdata/no_modules/go.mod
+++ /dev/null
@@ -1,3 +0,0 @@
-module no_modules
-
-go 1.23
diff --git a/integration/testdata/no_modules/main.go b/integration/testdata/no_modules/main.go
deleted file mode 100644
index 0862d468..00000000
--- a/integration/testdata/no_modules/main.go
+++ /dev/null
@@ -1,11 +0,0 @@
-package main
-
-import (
-	_ "embed"
-	"fmt"
-)
-
-//go:embed .occam-key
-func main() {
-	fmt.Println("Hello World!")
-}