Do not check DeprecationDate when comparing dependencies

buildpack.go

@@ -19,6 +19,7 @@ package libpak
 import (
 	"fmt"
 	"os"
+	"reflect"
 	"sort"
 	"strconv"
 	"strings"
@@ -95,6 +96,23 @@ type BuildpackDependency struct {
 	DeprecationDate time.Time `toml:"deprecation_date"`
 }
 
+// Equals compares the 2 structs if they are equal. This is very simiar to reflect.DeepEqual
+// except that properties that will not work (e.g. DeprecationDate) are ignored.
+func (b1 BuildpackDependency) Equals(b2 BuildpackDependency) bool {
+
+	b1.DeprecationDate = time.Time{}
+	b2.DeprecationDate = time.Time{}
+
+	if len(b1.CPEs) == 0 {
+		b1.CPEs = nil
+	}
+	if len(b2.CPEs) == 0 {
+		b2.CPEs = nil
+	}
+
+	return reflect.DeepEqual(b1, b2)
+}
+
 // AsBOMEntry renders a bill of materials entry describing the dependency.
 //
 // Deprecated: as of Buildpacks RFC 95, use `BuildpackDependency.AsSyftArtifact` instead

buildpack_test.go

@@ -25,6 +25,7 @@ import (
 
 	"github.com/buildpacks/libcnb"
 	. "github.com/onsi/gomega"
+	"github.com/pelletier/go-toml"
 	"github.com/sclevine/spec"
 
 	"github.com/paketo-buildpacks/libpak"
@@ -37,6 +38,33 @@ func testBuildpack(t *testing.T, context spec.G, it spec.S) {
 		Expect = NewWithT(t).Expect
 	)
 
+	it("is equal after toml Marshal and Unmarshal", func() {
+		dependency := libpak.BuildpackDependency{
+			ID:              "test-id",
+			Name:            "test-name",
+			Version:         "1.1.1",
+			URI:             "test-uri",
+			SHA256:          "test-sha256",
+			DeprecationDate: time.Now(),
+			Stacks:          []string{"test-stack"},
+			Licenses: []libpak.BuildpackDependencyLicense{
+				{
+					Type: "test-type",
+					URI:  "test-uri",
+				},
+			},
+		}
+
+		bytes, err := toml.Marshal(dependency)
+		Expect(err).NotTo(HaveOccurred())
+
+		var newDependency libpak.BuildpackDependency
+		err = toml.Unmarshal(bytes, &newDependency)
+		Expect(err).NotTo(HaveOccurred())
+
+		Expect(dependency.Equals(newDependency)).To(BeTrue())
+	})
+
 	it("renders dependency as a BOMEntry", func() {
 		dependency := libpak.BuildpackDependency{
 			ID:      "test-id",
@@ -573,6 +601,7 @@ func testBuildpack(t *testing.T, context spec.G, it spec.S) {
 				logger := bard.NewLogger(buff)
 				resolver.Logger = &logger
 				soonDeprecated := time.Now().UTC().Add(30 * 24 * time.Hour)
+				notSoSoonDeprecated := time.Now().UTC().Add(60 * 24 * time.Hour)
 				resolver.Dependencies = []libpak.BuildpackDependency{
 					{
 						ID:      "missing-deprecation-date",
@@ -583,7 +612,7 @@ func testBuildpack(t *testing.T, context spec.G, it spec.S) {
 						ID:              "valid-dependency",
 						Name:            "valid-dependency",
 						Version:         "1.1",
-						DeprecationDate: time.Now().UTC().Add(60 * 24 * time.Hour),
+						DeprecationDate: notSoSoonDeprecated,
 					},
 					{
 						ID:              "soon-deprecated-dependency",

dependency_cache.go

@@ -25,7 +25,6 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
-	"reflect"
 	"strings"
 
 	"github.com/buildpacks/libcnb"
@@ -138,7 +137,7 @@ func (d *DependencyCache) Artifact(dependency BuildpackDependency, mods ...Reque
 		return nil, fmt.Errorf("unable to decode download metadata %s\n%w", file, err)
 	}
 
-	if reflect.DeepEqual(dependency, actual) {
+	if dependency.Equals(actual) {
 		d.Logger.Bodyf("%s cached download from buildpack", color.GreenString("Reusing"))
 		return os.Open(filepath.Join(d.CachePath, dependency.SHA256, filepath.Base(uri)))
 	}
@@ -152,7 +151,7 @@ func (d *DependencyCache) Artifact(dependency BuildpackDependency, mods ...Reque
 		return nil, fmt.Errorf("unable to decode download metadata %s\n%w", file, err)
 	}
 
-	if reflect.DeepEqual(dependency, actual) {
+	if dependency.Equals(actual) {
 		d.Logger.Bodyf("%s previously cached download", color.GreenString("Reusing"))
 		return os.Open(filepath.Join(d.DownloadPath, dependency.SHA256, filepath.Base(uri)))
 	}

dependency_cache_test.go

@@ -23,6 +23,7 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+	"time"
 
 	"github.com/buildpacks/libcnb"
 	. "github.com/onsi/gomega"
@@ -140,12 +141,13 @@ func testDependencyCache(t *testing.T, context spec.G, it spec.S) {
 			server = ghttp.NewServer()
 
 			dependency = libpak.BuildpackDependency{
-				ID:      "test-id",
-				Name:    "test-name",
-				Version: "1.1.1",
-				URI:     fmt.Sprintf("%s/test-path", server.URL()),
-				SHA256:  "576dd8416de5619ea001d9662291d62444d1292a38e96956bc4651c01f14bca1",
-				Stacks:  []string{"test-stack"},
+				ID:              "test-id",
+				Name:            "test-name",
+				Version:         "1.1.1",
+				URI:             fmt.Sprintf("%s/test-path", server.URL()),
+				SHA256:          "576dd8416de5619ea001d9662291d62444d1292a38e96956bc4651c01f14bca1",
+				Stacks:          []string{"test-stack"},
+				DeprecationDate: time.Now(),
 				Licenses: []libpak.BuildpackDependencyLicense{
 					{
 						Type: "test-type",