adds test to verify a downloaded artifact has expected sha256 filename

Signed-off-by: Amit Singh <[email protected]>

dependency_cache_test.go

@@ -20,6 +20,7 @@ import (
 	"crypto/sha256"
 	"encoding/hex"
 	"fmt"
+	"hash"
 	"io"
 	"net/http"
 	"os"
@@ -157,6 +158,7 @@ func testDependencyCache(t *testing.T, context spec.G, it spec.S) {
 			downloadPath    string
 			dependency      libpak.BuildpackDependency
 			dependencyCache libpak.DependencyCache
+			hasher          hash.Hash
 			server          *ghttp.Server
 		)
 
@@ -166,6 +168,8 @@ func testDependencyCache(t *testing.T, context spec.G, it spec.S) {
 			cachePath = t.TempDir()
 			Expect(err).NotTo(HaveOccurred())
 
+			hasher = sha256.New()
+
 			downloadPath = t.TempDir()
 			Expect(err).NotTo(HaveOccurred())
 
@@ -319,12 +323,23 @@ func testDependencyCache(t *testing.T, context spec.G, it spec.S) {
 			Expect(io.ReadAll(a)).To(Equal([]byte("alternate-fixture")))
 		})
 
+		it("sets downloaded file name to uri's sha256", func() {
+			server.AppendHandlers(ghttp.RespondWith(http.StatusOK, "test-fixture"))
+
+			hasher.Write([]byte(dependency.URI))
+
+			a, err := dependencyCache.Artifact(dependency)
+			Expect(err).NotTo(HaveOccurred())
+
+			Expect(io.ReadAll(a)).To(Equal([]byte("test-fixture")))
+			Expect(filepath.Base(a.Name())).To(Equal(hex.EncodeToString(hasher.Sum(nil))))
+		})
+
 		it("sets downloaded file name to uri's sha256 with empty SHA256 and query parameters in the uri", func() {
 			dependency.SHA256 = ""
 			dependency.URI = fmt.Sprintf("%s/test-path?param1=value1&param2=value2", server.URL())
 			server.AppendHandlers(ghttp.RespondWith(http.StatusOK, "alternate-fixture"))
 
-			hasher := sha256.New()
 			hasher.Write([]byte(dependency.URI))
 
 			a, err := dependencyCache.Artifact(dependency)