Close paketo-buildpacks#252 : Disable ToLower in some cases

* use lowercase to perform the comparison, and keep the original passed
  as an argument

jlink.go

@@ -84,8 +84,8 @@ func (j JLink) Contribute(layer libcnb.Layer) (libcnb.Layer, error) {
 		}
 
 		cacertsPath := filepath.Join(layer.Path, "lib", "security", "cacerts")
-		if err := os.Chmod(cacertsPath, 0664); err != nil{
-			return  libcnb.Layer{}, fmt.Errorf("unable to set keystore file permissions\n%w", err)
+		if err := os.Chmod(cacertsPath, 0664); err != nil {
+			return libcnb.Layer{}, fmt.Errorf("unable to set keystore file permissions\n%w", err)
 		}
 
 		if IsBeforeJava18(j.JavaVersion) {
@@ -155,12 +155,12 @@ func (j *JLink) buildCustomJRE(layerPath string) error {
 func (j *JLink) validArgs() bool {
 	jlinkArgs := j.Args[:0]
 	var skipNext, modsFound bool
-	for _, a := range j.Args {
+	for _, original := range j.Args {
 		if skipNext {
 			skipNext = false
 			continue
 		}
-		a = strings.ToLower(a)
+		var a = strings.ToLower(original)
 		if strings.HasPrefix(a, "--output") {
 			j.Logger.Bodyf(color.New(color.Faint, color.Bold).Sprint("WARNING: explicitly specified '--output' option & value will be overridden"))
 			skipNext = true
@@ -169,7 +169,7 @@ func (j *JLink) validArgs() bool {
 		if strings.HasPrefix(a, "--add-modules") {
 			modsFound = true
 		}
-		jlinkArgs = append(jlinkArgs, a)
+		jlinkArgs = append(jlinkArgs, original)
 	}
 	j.Args = jlinkArgs
 	if !modsFound {

jlink_test.go

@@ -21,7 +21,7 @@ import (
 	"github.com/paketo-buildpacks/libpak/effect"
 	"github.com/paketo-buildpacks/libpak/effect/mocks"
 	"github.com/stretchr/testify/mock"
-	"io/ioutil"
+	"io"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -42,7 +42,7 @@ func testJLink(t *testing.T, context spec.G, it spec.S) {
 
 		cl = libjvm.CertificateLoader{
 			CertDirs: []string{filepath.Join("testdata", "certificates")},
-			Logger:   ioutil.Discard,
+			Logger:   io.Discard,
 		}
 
 		ctx libcnb.BuildContext
@@ -52,7 +52,7 @@ func testJLink(t *testing.T, context spec.G, it spec.S) {
 		var err error
 		Expect(os.Setenv("BP_JVM_JLINK_ENABLED", "true")).To(Succeed())
 
-		ctx.Layers.Path, err = ioutil.TempDir("", "jdk")
+		ctx.Layers.Path, err = os.MkdirTemp("", "jdk")
 		Expect(err).NotTo(HaveOccurred())
 	})
 
@@ -68,7 +68,7 @@ func testJLink(t *testing.T, context spec.G, it spec.S) {
 		exec := &mocks.Executor{}
 		j, err := libjvm.NewJLink(ctx.Application.Path, exec, args, cl, LaunchContribution, false)
 		Expect(err).NotTo(HaveOccurred())
-		j.Logger = bard.NewLogger(ioutil.Discard)
+		j.Logger = bard.NewLogger(io.Discard)
 
 		Expect(j.LayerContributor.ExpectedMetadata.(map[string]interface{})["cert-dir"]).To(HaveLen(4))
 
@@ -108,7 +108,7 @@ func testJLink(t *testing.T, context spec.G, it spec.S) {
 		exec := &mocks.Executor{}
 		j, err := libjvm.NewJLink(ctx.Application.Path, exec, args, cl, LaunchContribution, true)
 		Expect(err).NotTo(HaveOccurred())
-		j.Logger = bard.NewLogger(ioutil.Discard)
+		j.Logger = bard.NewLogger(io.Discard)
 
 		Expect(j.LayerContributor.ExpectedMetadata.(map[string]interface{})["cert-dir"]).To(HaveLen(4))
 
@@ -132,13 +132,46 @@ func testJLink(t *testing.T, context spec.G, it spec.S) {
 		Expect(e.Args).To(ContainElement("java.se"))
 	})
 
+	it("contributes jlink JRE with user provided all caps --add-modules argument", func() {
+
+		args := []string{"--no-man-pages", "--no-header-files", "--strip-debug", "--add-modules", "ALL-MODULE-PATH"}
+		exec := &mocks.Executor{}
+		j, err := libjvm.NewJLink(ctx.Application.Path, exec, args, cl, LaunchContribution, true)
+		Expect(err).NotTo(HaveOccurred())
+		j.Logger = bard.NewLogger(io.Discard)
+
+		Expect(j.LayerContributor.ExpectedMetadata.(map[string]interface{})["cert-dir"]).To(HaveLen(4))
+
+		layer, err := ctx.Layers.Layer("jlink")
+		Expect(err).NotTo(HaveOccurred())
+
+		exec.On("Execute", mock.Anything).Run(func(args mock.Arguments) {
+			err = os.MkdirAll(filepath.Join(ctx.Layers.Path, "jlink"), os.ModePerm)
+			jre, err := os.Open("testdata/3aa01010c0d3592ea248c8353d60b361231fa9bf9a7479b4f06451fef3e64524/stub-jre-11.tar.gz")
+			Expect(err).NotTo(HaveOccurred())
+			err = crush.Extract(jre, layer.Path, 1)
+			Expect(err).NotTo(HaveOccurred())
+		}).Return(nil)
+
+		layer, err = j.Contribute(layer)
+		Expect(err).NotTo(HaveOccurred())
+
+		e := exec.Calls[0].Arguments[0].(effect.Execution)
+		Expect(e.Args).To(ContainElement("--output"))
+		Expect(e.Args).To(ContainElement("--no-man-pages"))
+		Expect(e.Args).To(ContainElement("--no-header-files"))
+		Expect(e.Args).To(ContainElement("--strip-debug"))
+		Expect(e.Args).To(ContainElement("--add-modules"))
+		Expect(e.Args).To(ContainElement("ALL-MODULE-PATH"))
+	})
+
 	it("contributes jlink JRE with user provided args & missing modules", func() {
 
 		args := []string{"--no-man-pages", "--no-header-files", "--strip-debug"}
 		exec := &mocks.Executor{}
 		j, err := libjvm.NewJLink(ctx.Application.Path, exec, args, cl, LaunchContribution, true)
 		Expect(err).NotTo(HaveOccurred())
-		j.Logger = bard.NewLogger(ioutil.Discard)
+		j.Logger = bard.NewLogger(io.Discard)
 
 		Expect(j.LayerContributor.ExpectedMetadata.(map[string]interface{})["cert-dir"]).To(HaveLen(4))