Stop using regex to update dependencies in builder.toml, package.toml, and buildpack.toml

carton/buildpack_dependency.go

@@ -17,13 +17,15 @@
 package carton
 
 import (
+	"bytes"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"regexp"
 
 	"github.com/paketo-buildpacks/libpak/bard"
 	"github.com/paketo-buildpacks/libpak/internal"
+	"github.com/pelletier/go-toml"
 )
 
 const (
@@ -55,26 +57,94 @@ func (b BuildpackDependency) Update(options ...Option) {
 	logger.Headerf("URI:     %s", b.URI)
 	logger.Headerf("SHA256:  %s", b.SHA256)
 
+	versionExp, err := regexp.Compile(b.VersionPattern)
+	if err != nil {
+		config.exitHandler.Error(fmt.Errorf("unable to compile regex %s\n%w", b.VersionPattern, err))
+		return
+	}
+
 	c, err := ioutil.ReadFile(b.BuildpackPath)
 	if err != nil {
 		config.exitHandler.Error(fmt.Errorf("unable to read %s\n%w", b.BuildpackPath, err))
 		return
 	}
 
-	s := fmt.Sprintf(BuildpackDependencyPattern, b.ID, b.VersionPattern)
-	r, err := regexp.Compile(s)
-	if err != nil {
-		config.exitHandler.Error(fmt.Errorf("unable to compile regex %s\n%w", s, err))
+	// save any leading comments, this is to preserve license headers
+	// inline comments will be lost
+	comments := []byte{}
+	for i, line := range bytes.SplitAfter(c, []byte("\n")) {
+		if bytes.HasPrefix(line, []byte("#")) || (i > 0 && len(bytes.TrimSpace(line)) == 0) {
+			comments = append(comments, line...)
+		} else {
+			break // stop on first comment
+		}
+	}
+
+	md := make(map[string]interface{})
+	if err := toml.Unmarshal(c, &md); err != nil {
+		config.exitHandler.Error(fmt.Errorf("unable to decode md%s\n%w", b.BuildpackPath, err))
+		return
+	}
+
+	metadataUnwrapped, found := md["metadata"]
+	if !found {
+		config.exitHandler.Error(fmt.Errorf("unable to find metadata block"))
+		return
+	}
+
+	metadata, ok := metadataUnwrapped.(map[string]interface{})
+	if !ok {
+		config.exitHandler.Error(fmt.Errorf("unable to cast metadata"))
+		return
+	}
+
+	dependenciesUnwrapped, found := metadata["dependencies"]
+	if !found {
+		config.exitHandler.Error(fmt.Errorf("unable to find dependencies block"))
+		return
+	}
+
+	dependencies, ok := dependenciesUnwrapped.([]map[string]interface{})
+	if !ok {
+		config.exitHandler.Error(fmt.Errorf("unable to cast dependencies"))
 		return
 	}
 
-	if !r.Match(c) {
-		config.exitHandler.Error(fmt.Errorf("unable to match '%s' '%s'", b.ID, b.VersionPattern))
+	for _, dep := range dependencies {
+		depIdUnwrapped, found := dep["id"]
+		if !found {
+			continue
+		}
+		depId, ok := depIdUnwrapped.(string)
+		if !ok {
+			continue
+		}
+
+		if depId == b.ID {
+			depVersionUnwrapped, found := dep["version"]
+			if !found {
+				continue
+			}
+
+			depVersion, ok := depVersionUnwrapped.(string)
+			if !ok {
+				continue
+			}
+			if versionExp.MatchString(depVersion) {
+				dep["version"] = b.Version
+				dep["uri"] = b.URI
+				dep["sha256"] = b.SHA256
+			}
+		}
+	}
+
+	c, err = toml.Marshal(md)
+	if err != nil {
+		config.exitHandler.Error(fmt.Errorf("unable to encode md %s\n%w", b.BuildpackPath, err))
 		return
 	}
 
-	s = fmt.Sprintf(BuildpackDependencySubstitution, b.Version, b.URI, b.SHA256)
-	c = r.ReplaceAll(c, []byte(s))
+	c = append(comments, c...)
 
 	if err := ioutil.WriteFile(b.BuildpackPath, c, 0644); err != nil {
 		config.exitHandler.Error(fmt.Errorf("unable to write %s\n%w", b.BuildpackPath, err))

carton/buildpack_dependency_test.go

@@ -27,6 +27,7 @@ import (
 	"github.com/stretchr/testify/mock"
 
 	"github.com/paketo-buildpacks/libpak/carton"
+	"github.com/paketo-buildpacks/libpak/internal"
 )
 
 func testBuildpackDependency(t *testing.T, context spec.G, it spec.S) {
@@ -54,7 +55,14 @@ func testBuildpackDependency(t *testing.T, context spec.G, it spec.S) {
 	})
 
 	it("updates dependency", func() {
-		Expect(ioutil.WriteFile(path, []byte(`id      = "test-id"
+		Expect(ioutil.WriteFile(path, []byte(`api = "0.6"
+[buildpack]
+id = "some-buildpack"
+name = "Some Buildpack"
+version = "1.2.3"
+
+[[metadata.dependencies]]
+id      = "test-id"
 name    = "Test Name"
 version = "test-version-1"
 uri     = "test-uri-1"
@@ -73,17 +81,34 @@ stacks  = [ "test-stack" ]
 
 		d.Update(carton.WithExitHandler(exitHandler))
 
-		Expect(ioutil.ReadFile(path)).To(Equal([]byte(`id      = "test-id"
+		Expect(ioutil.ReadFile(path)).To(internal.MatchTOML(`api = "0.6"
+[buildpack]
+id = "some-buildpack"
+name = "Some Buildpack"
+version = "1.2.3"
+
+[[metadata.dependencies]]id      = "test-id"
 name    = "Test Name"
 version = "test-version-2"
 uri     = "test-uri-2"
 sha256  = "test-sha256-2"
 stacks  = [ "test-stack" ]
-`)))
+`))
 	})
 
 	it("updates indented dependency", func() {
-		Expect(ioutil.WriteFile(path, []byte(`  id      = "test-id"
+		Expect(ioutil.WriteFile(path, []byte(`# it should preserve
+#   these comments
+#      exactly
+
+api = "0.6"
+[buildpack]
+id = "some-buildpack"
+name = "Some Buildpack"
+version = "1.2.3"
+
+[[metadata.dependencies]]
+  id      = "test-id"
   name    = "Test Name"
   version = "test-version-1"
   uri     = "test-uri-1"
@@ -102,13 +127,26 @@ stacks  = [ "test-stack" ]
 
 		d.Update(carton.WithExitHandler(exitHandler))
 
-		Expect(ioutil.ReadFile(path)).To(Equal([]byte(`  id      = "test-id"
+		body, err := ioutil.ReadFile(path)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(string(body)).To(HavePrefix(`# it should preserve
+#   these comments
+#      exactly
+
+api = "0.6"`))
+		Expect(body).To(internal.MatchTOML(`api = "0.6"
+[buildpack]
+id = "some-buildpack"
+name = "Some Buildpack"
+version = "1.2.3"
+
+[[metadata.dependencies]]
+  id      = "test-id"
   name    = "Test Name"
   version = "test-version-2"
   uri     = "test-uri-2"
   sha256  = "test-sha256-2"
   stacks  = [ "test-stack" ]
-`)))
+`))
 	})
-
 }

carton/package.go

@@ -188,7 +188,7 @@ func (p Package) Create(options ...Option) {
 	}
 
 	var files []string
-	for d, _ := range entries {
+	for d := range entries {
 		files = append(files, d)
 	}
 	sort.Strings(files)