Tidy Up

.gitignore

@@ -1 +1,3 @@
 /.bin
+.idea/
+.DS_Store

README.md

@@ -22,17 +22,17 @@ file that looks like the following:
   # for deprecation.
   name = "yarn"
 
-  # The version of the Yarn dependency is not required. In the case it
-  # is not specified, the buildpack will provide the default version, which can
-  # be seen in the buildpack.toml file.
-  # If you wish to request a specific version, the buildpack supports
-  # specifying a semver constraint in the form of "1.*", "1.22.*", or even
-  # "1.22.4".
-  version = "1.22.4"
-
   # The Yarn buildpack supports some non-required metadata options.
   [requires.metadata]
 
+    # The version of the Yarn dependency is not required. In the case it
+    # is not specified, the buildpack will provide the default version, which can
+    # be seen in the buildpack.toml file.
+    # If you wish to request a specific version, the buildpack supports
+    # specifying a semver constraint in the form of "1.*", "1.22.*", or even
+    # "1.22.4".
+    version = "1.22.4"
+
     # Setting the build flag to true will ensure that the yarn
     # depdendency is available on the $PATH for subsequent buildpacks during
     # their build phase. If you are writing a buildpack that needs to run yarn
@@ -50,15 +50,18 @@ file that looks like the following:
 
 To package this buildpack for consumption:
 
-```
+```shell
 $ ./scripts/package.sh --version <version-number>
 ```
 
 This will create a `buildpackage.cnb` file under the `build` directory which you
 can use to build your app as follows:
-```
-pack build <app-name> -p <path-to-app> -b <path/to/node-engine.cnb> -b build/buildpackage.cnb \
--b <path/to/node-and-yarn-requiring-cnb>
+```shell
+pack build <app-name> \
+  --path <path-to-app> \
+  --buildpack <path/to/node-engine.cnb> \
+  --buildpack build/buildpackage.cnb \
+  --buildpack <path/to/cnb-that-requires-node-and-yarn>
 ```
 
 Though the API of this buildpack does not require `node`, yarn is unusable without node.
@@ -70,11 +73,11 @@ There are no extra configurations for this buildpack based on `buildpack.yml`.
 ## Run Tests
 
 To run all unit tests, run:
-```
+```shell
 ./scripts/unit.sh
 ```
 
 To run all integration tests, run:
-```
+```shell
 /scripts/integration.sh
 ```

build.go

@@ -9,17 +9,12 @@ import (
 
 	"github.com/paketo-buildpacks/packit/v2"
 	"github.com/paketo-buildpacks/packit/v2/chronos"
+	"github.com/paketo-buildpacks/packit/v2/draft"
 	"github.com/paketo-buildpacks/packit/v2/postal"
 	"github.com/paketo-buildpacks/packit/v2/sbom"
 	"github.com/paketo-buildpacks/packit/v2/scribe"
 )
 
-//go:generate faux --interface EntryResolver --output fakes/entry_resolver.go
-type EntryResolver interface {
-	Resolve(name string, entries []packit.BuildpackPlanEntry, priorites []interface{}) (packit.BuildpackPlanEntry, []packit.BuildpackPlanEntry)
-	MergeLayerTypes(name string, entries []packit.BuildpackPlanEntry) (launch, build bool)
-}
-
 //go:generate faux --interface DependencyManager --output fakes/dependency_manager.go
 type DependencyManager interface {
 	Resolve(path, id, version, stack string) (postal.Dependency, error)
@@ -33,7 +28,6 @@ type SBOMGenerator interface {
 }
 
 func Build(
-	entryResolver EntryResolver,
 	dependencyManager DependencyManager,
 	sbomGenerator SBOMGenerator,
 	clock chronos.Clock,
@@ -47,7 +41,8 @@ func Build(
 			return packit.BuildResult{}, err
 		}
 
-		entry, _ := entryResolver.Resolve("yarn", context.Plan.Entries, nil)
+		planner := draft.NewPlanner()
+		entry, _ := planner.Resolve("yarn", context.Plan.Entries, nil)
 		version, ok := entry.Metadata["version"].(string)
 		if !ok {
 			version = "default"
@@ -64,7 +59,7 @@ func Build(
 
 		bom := dependencyManager.GenerateBillOfMaterials(dependency)
 
-		launch, build := entryResolver.MergeLayerTypes("yarn", context.Plan.Entries)
+		launch, build := planner.MergeLayerTypes("yarn", context.Plan.Entries)
 
 		var buildMetadata = packit.BuildMetadata{}
 		var launchMetadata = packit.LaunchMetadata{}

build_test.go

@@ -29,13 +29,13 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		layersDir         string
 		workingDir        string
 		cnbDir            string
-		entryResolver     *fakes.EntryResolver
 		dependencyManager *fakes.DependencyManager
 		sbomGenerator     *fakes.SBOMGenerator
 
 		buffer *bytes.Buffer
 
-		build packit.BuildFunc
+		buildContext packit.BuildContext
+		build        packit.BuildFunc
 	)
 
 	it.Before(func() {
@@ -49,11 +49,6 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		workingDir, err = os.MkdirTemp("", "working-dir")
 		Expect(err).NotTo(HaveOccurred())
 
-		entryResolver = &fakes.EntryResolver{}
-		entryResolver.ResolveCall.Returns.BuildpackPlanEntry = packit.BuildpackPlanEntry{
-			Name: "yarn",
-		}
-
 		dependencyManager = &fakes.DependencyManager{}
 		dependencyManager.ResolveCall.Returns.Dependency = postal.Dependency{
 			ID:      "yarn",
@@ -81,21 +76,8 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		sbomGenerator.GenerateFromDependencyCall.Returns.SBOM = sbom.SBOM{}
 
 		buffer = bytes.NewBuffer(nil)
-		build = yarn.Build(entryResolver,
-			dependencyManager,
-			sbomGenerator,
-			chronos.DefaultClock,
-			scribe.NewEmitter(buffer))
-	})
-
-	it.After(func() {
-		Expect(os.RemoveAll(layersDir)).To(Succeed())
-		Expect(os.RemoveAll(cnbDir)).To(Succeed())
-		Expect(os.RemoveAll(workingDir)).To(Succeed())
-	})
 
-	it("returns a result that installs yarn", func() {
-		result, err := build(packit.BuildContext{
+		buildContext = packit.BuildContext{
 			WorkingDir: workingDir,
 			CNBPath:    cnbDir,
 			Stack:      "some-stack",
@@ -113,7 +95,22 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 			},
 			Platform: packit.Platform{Path: "platform"},
 			Layers:   packit.Layers{Path: layersDir},
-		})
+		}
+
+		build = yarn.Build(dependencyManager,
+			sbomGenerator,
+			chronos.DefaultClock,
+			scribe.NewEmitter(buffer))
+	})
+
+	it.After(func() {
+		Expect(os.RemoveAll(layersDir)).To(Succeed())
+		Expect(os.RemoveAll(cnbDir)).To(Succeed())
+		Expect(os.RemoveAll(workingDir)).To(Succeed())
+	})
+
+	it("returns a result that installs yarn", func() {
+		result, err := build(buildContext)
 		Expect(err).NotTo(HaveOccurred())
 
 		Expect(result.Layers).To(HaveLen(1))
@@ -136,16 +133,6 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 			},
 		}))
 
-		Expect(entryResolver.ResolveCall.Receives.Name).To(Equal("yarn"))
-		Expect(entryResolver.ResolveCall.Receives.Entries).To(Equal([]packit.BuildpackPlanEntry{
-			{Name: "yarn"},
-		}))
-
-		Expect(entryResolver.MergeLayerTypesCall.Receives.Name).To(Equal("yarn"))
-		Expect(entryResolver.MergeLayerTypesCall.Receives.Entries).To(Equal([]packit.BuildpackPlanEntry{
-			{Name: "yarn"},
-		}))
-
 		Expect(dependencyManager.ResolveCall.Receives.Path).To(Equal(filepath.Join(cnbDir, "buildpack.toml")))
 		Expect(dependencyManager.ResolveCall.Receives.Id).To(Equal("yarn"))
 		Expect(dependencyManager.ResolveCall.Receives.Stack).To(Equal("some-stack"))
@@ -190,27 +177,14 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 
 	context("when the plan entry requires the dependency during the build and launch phases", func() {
 		it.Before(func() {
-			entryResolver.MergeLayerTypesCall.Returns.Launch = true
-			entryResolver.MergeLayerTypesCall.Returns.Build = true
+			buildContext.Plan.Entries[0].Metadata = map[string]interface{}{
+				"build":  true,
+				"launch": true,
+			}
 		})
 
 		it("makes the layer available in those phases", func() {
-			result, err := build(packit.BuildContext{
-				CNBPath: cnbDir,
-				Plan: packit.BuildpackPlan{
-					Entries: []packit.BuildpackPlanEntry{
-						{
-							Name: "yarn",
-							Metadata: map[string]interface{}{
-								"build":  true,
-								"launch": true,
-							},
-						},
-					},
-				},
-				Layers: packit.Layers{Path: layersDir},
-				Stack:  "some-stack",
-			})
+			result, err := build(buildContext)
 			Expect(err).NotTo(HaveOccurred())
 
 			Expect(result.Layers).To(HaveLen(1))
@@ -235,16 +209,7 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 			})
 
 			it("returns an error", func() {
-				_, err := build(packit.BuildContext{
-					CNBPath: cnbDir,
-					Plan: packit.BuildpackPlan{
-						Entries: []packit.BuildpackPlanEntry{
-							{Name: "yarn"},
-						},
-					},
-					Layers: packit.Layers{Path: layersDir},
-					Stack:  "some-stack",
-				})
+				_, err := build(buildContext)
 				Expect(err).To(MatchError(ContainSubstring("failed to parse layer content metadata")))
 			})
 		})
@@ -255,16 +220,7 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 			})
 
 			it("returns an error", func() {
-				_, err := build(packit.BuildContext{
-					CNBPath: cnbDir,
-					Plan: packit.BuildpackPlan{
-						Entries: []packit.BuildpackPlanEntry{
-							{Name: "yarn"},
-						},
-					},
-					Layers: packit.Layers{Path: layersDir},
-					Stack:  "some-stack",
-				})
+				_, err := build(buildContext)
 				Expect(err).To(MatchError("failed to resolve dependency"))
 			})
 		})
@@ -279,15 +235,7 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 			})
 
 			it("returns an error", func() {
-				_, err := build(packit.BuildContext{
-					CNBPath: cnbDir,
-					Plan: packit.BuildpackPlan{
-						Entries: []packit.BuildpackPlanEntry{
-							{Name: "yarn"},
-						},
-					},
-					Layers: packit.Layers{Path: layersDir},
-				})
+				_, err := build(buildContext)
 				Expect(err).To(MatchError(ContainSubstring("permission denied")))
 			})
 		})
@@ -298,33 +246,18 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 			})
 
 			it("returns an error", func() {
-				_, err := build(packit.BuildContext{
-					CNBPath: cnbDir,
-					Plan: packit.BuildpackPlan{
-						Entries: []packit.BuildpackPlanEntry{
-							{Name: "yarn"},
-						},
-					},
-					Layers: packit.Layers{Path: layersDir},
-					Stack:  "some-stack",
-				})
+				_, err := build(buildContext)
 				Expect(err).To(MatchError("failed to install dependency"))
 			})
 		})
 
 		context("when generating the SBOM returns an error", func() {
+			it.Before(func() {
+				buildContext.BuildpackInfo = packit.BuildpackInfo{SBOMFormats: []string{"random-format"}}
+			})
+
 			it("returns an error", func() {
-				_, err := build(packit.BuildContext{
-					BuildpackInfo: packit.BuildpackInfo{SBOMFormats: []string{"random-format"}},
-					CNBPath:       cnbDir,
-					Plan: packit.BuildpackPlan{
-						Entries: []packit.BuildpackPlanEntry{
-							{Name: "yarn"},
-						},
-					},
-					Layers: packit.Layers{Path: layersDir},
-					Stack:  "some-stack",
-				})
+				_, err := build(buildContext)
 				Expect(err).To(MatchError("unsupported SBOM format: 'random-format'"))
 			})
 		})
@@ -335,38 +268,22 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 			})
 
 			it("returns an error", func() {
-				_, err := build(packit.BuildContext{
-					CNBPath: cnbDir,
-					Plan: packit.BuildpackPlan{
-						Entries: []packit.BuildpackPlanEntry{
-							{Name: "yarn"},
-						},
-					},
-					Layers: packit.Layers{Path: layersDir},
-					Stack:  "some-stack",
-				})
+				_, err := build(buildContext)
 				Expect(err).To(MatchError(ContainSubstring("failed to generate SBOM")))
 			})
 		})
 
 		context("when BP_DISABLE_SBOM is set incorrectly", func() {
 			it.Before(func() {
-				os.Setenv("BP_DISABLE_SBOM", "not-a-bool")
+				Expect(os.Setenv("BP_DISABLE_SBOM", "not-a-bool")).To(Succeed())
 			})
 
 			it.After(func() {
-				os.Unsetenv("BP_DISABLE_SBOM")
+				Expect(os.Unsetenv("BP_DISABLE_SBOM")).To(Succeed())
 			})
 
 			it("returns an error", func() {
-				_, err := build(packit.BuildContext{
-					BuildpackInfo: packit.BuildpackInfo{
-						Name:        "Some Buildpack",
-						Version:     "some-version",
-						SBOMFormats: []string{sbom.CycloneDXFormat, sbom.SPDXFormat},
-					},
-				})
-
+				_, err := build(buildContext)
 				Expect(err).To(MatchError(ContainSubstring("failed to parse BP_DISABLE_SBOM")))
 			})
 		})