Linkify plugin versions in generated PR

internal/cmd/fetcher/main.go

@@ -125,11 +125,13 @@ func newRootCommand(name string) *appcmd.Command {
 }
 
 type createdPlugin struct {
-	org             string
-	name            string
-	pluginDir       string
-	previousVersion string
-	newVersion      string
+	org                string
+	name               string
+	pluginDir          string
+	previousVersion    string
+	newVersion         string
+	previousReleaseURL string
+	releaseURL         string
 }
 
 func (p createdPlugin) String() string {
@@ -382,9 +384,11 @@ func updatePluginDeps(ctx context.Context, logger *slog.Logger, content []byte,
 
 // pluginToCreate represents a plugin that needs a new version created.
 type pluginToCreate struct {
-	pluginDir       string
-	previousVersion string
-	newVersion      string
+	pluginDir          string
+	previousVersion    string
+	newVersion         string
+	previousReleaseURL string
+	releaseURL         string
 }
 
 type runOption func(*runOptions)
@@ -499,16 +503,52 @@ func run(
 		latestPluginVersions[p.Name] = pending.newVersion
 
 		created = append(created, createdPlugin{
-			org:             filepath.Base(filepath.Dir(pending.pluginDir)),
-			name:            filepath.Base(pending.pluginDir),
-			pluginDir:       pending.pluginDir,
-			previousVersion: pending.previousVersion,
-			newVersion:      pending.newVersion,
+			org:                filepath.Base(filepath.Dir(pending.pluginDir)),
+			name:               filepath.Base(pending.pluginDir),
+			pluginDir:          pending.pluginDir,
+			previousVersion:    pending.previousVersion,
+			newVersion:         pending.newVersion,
+			previousReleaseURL: pending.previousReleaseURL,
+			releaseURL:         pending.releaseURL,
 		})
 	}
 	return created, nil
 }
 
+// pluginReleaseURL returns the release URL for a new plugin version, or empty string if not determinable.
+// For GitHub sources, reads the previous version's buf.plugin.yaml to determine
+// whether the repo uses v-prefixed tags (e.g. v1.2.3) or bare tags (e.g. 1.2.3).
+func pluginReleaseURL(pluginDir, previousVersion, newVersion string, src source.Source) string {
+	bare := strings.TrimPrefix(newVersion, "v")
+	switch {
+	case src.GitHub != nil:
+		tag := newVersion // default: v-prefixed
+		// Check the previous buf.plugin.yaml to see which tag format the repo uses.
+		prevYAML := filepath.Join(pluginDir, previousVersion, "buf.plugin.yaml")
+		if content, err := os.ReadFile(prevYAML); err == nil {
+			prevBare := strings.TrimPrefix(previousVersion, "v")
+			// If the file contains the bare version but NOT the v-prefixed version
+			// in a blob/tree URL, the repo uses bare tags.
+			if strings.Contains(string(content), "/blob/"+prevBare) && !strings.Contains(string(content), "/blob/v"+prevBare) {
+				tag = bare
+			}
+		}
+		return "https://github.com/" + src.GitHub.Owner + "/" + src.GitHub.Repository + "/releases/tag/" + tag
+	case src.GoProxy != nil:
+		return "https://pkg.go.dev/" + src.GoProxy.Name + "@" + newVersion
+	case src.NPMRegistry != nil:
+		return "https://www.npmjs.com/package/" + src.NPMRegistry.Name + "/v/" + bare
+	case src.Maven != nil:
+		groupPath := strings.ReplaceAll(src.Maven.Group, ".", "/")
+		return "https://mvnrepository.com/artifact/" + groupPath + "/" + src.Maven.Name + "/" + bare
+	case src.Crates != nil:
+		return "https://crates.io/crates/" + src.Crates.CrateName + "/" + bare
+	case src.DartFlutter != nil:
+		return "https://pub.dev/packages/" + src.DartFlutter.Name + "/versions/" + bare
+	}
+	return ""
+}
+
 // fetchPendingCreations iterates over source configs, fetches the latest
 // version for each enabled plugin, and returns a map of plugin directories
 // that need a new version created.
@@ -582,9 +622,11 @@ func fetchPendingCreations(
 		}
 
 		pendingCreations[pluginDir] = &pluginToCreate{
-			pluginDir:       pluginDir,
-			previousVersion: previousVersion,
-			newVersion:      newVersion,
+			pluginDir:          pluginDir,
+			previousVersion:    previousVersion,
+			newVersion:         newVersion,
+			previousReleaseURL: pluginReleaseURL(pluginDir, previousVersion, previousVersion, config.Source),
+			releaseURL:         pluginReleaseURL(pluginDir, previousVersion, newVersion, config.Source),
 		}
 	}
 	return pendingCreations, nil
@@ -908,10 +950,18 @@ func generatePRBody(created []createdPlugin) string {
 		}
 		fmt.Fprintf(&sb, "### %s\n", g.name)
 		for _, p := range g.plugins {
+			prevVersionLink := p.previousVersion
+			if p.previousReleaseURL != "" {
+				prevVersionLink = "[" + p.previousVersion + "](" + p.previousReleaseURL + ")"
+			}
+			newVersionLink := p.newVersion
+			if p.releaseURL != "" {
+				newVersionLink = "[" + p.newVersion + "](" + p.releaseURL + ")"
+			}
 			if p.org == communityOrg {
-				fmt.Fprintf(&sb, "- %s → %s\n", p.previousVersion, p.newVersion)
+				fmt.Fprintf(&sb, "- %s → %s\n", prevVersionLink, newVersionLink)
 			} else {
-				fmt.Fprintf(&sb, "- %s: %s → %s\n", p.name, p.previousVersion, p.newVersion)
+				fmt.Fprintf(&sb, "- %s: %s → %s\n", p.name, prevVersionLink, newVersionLink)
 			}
 		}
 	}

internal/cmd/fetcher/main_test.go

@@ -398,6 +398,140 @@ COPY --from=consumer /binary /usr/local/bin/protoc-gen-consumer
 	))
 }
 
+func TestPluginReleaseURL(t *testing.T) {
+	t.Parallel()
+
+	t.Run("github with v-prefixed tags", func(t *testing.T) {
+		t.Parallel()
+		tmpDir := t.TempDir()
+		pluginDir := filepath.Join(tmpDir, "plugins", "protocolbuffers", "go")
+		require.NoError(t, os.MkdirAll(filepath.Join(pluginDir, "v1.36.5"), 0755))
+		require.NoError(t, os.WriteFile(
+			filepath.Join(pluginDir, "v1.36.5", "buf.plugin.yaml"),
+			[]byte("license_url: https://github.com/protocolbuffers/protobuf-go/blob/v1.36.5/LICENSE\n"),
+			0644,
+		))
+		src := source.Source{GitHub: &source.GitHubConfig{Owner: "protocolbuffers", Repository: "protobuf-go"}}
+		url := pluginReleaseURL(pluginDir, "v1.36.5", "v1.37.0", src)
+		assert.Equal(t, "https://github.com/protocolbuffers/protobuf-go/releases/tag/v1.37.0", url)
+	})
+
+	t.Run("github with bare tags (no v prefix)", func(t *testing.T) {
+		t.Parallel()
+		tmpDir := t.TempDir()
+		pluginDir := filepath.Join(tmpDir, "plugins", "connectrpc", "swift")
+		require.NoError(t, os.MkdirAll(filepath.Join(pluginDir, "v1.2.1"), 0755))
+		require.NoError(t, os.WriteFile(
+			filepath.Join(pluginDir, "v1.2.1", "buf.plugin.yaml"),
+			[]byte("license_url: https://github.com/connectrpc/connect-swift/blob/1.2.1/LICENSE\n"),
+			0644,
+		))
+		src := source.Source{GitHub: &source.GitHubConfig{Owner: "connectrpc", Repository: "connect-swift"}}
+		url := pluginReleaseURL(pluginDir, "v1.2.1", "v1.2.2", src)
+		assert.Equal(t, "https://github.com/connectrpc/connect-swift/releases/tag/1.2.2", url)
+	})
+
+	t.Run("github falls back to v-prefix when no previous yaml", func(t *testing.T) {
+		t.Parallel()
+		tmpDir := t.TempDir()
+		pluginDir := filepath.Join(tmpDir, "plugins", "test", "myplugin")
+		require.NoError(t, os.MkdirAll(pluginDir, 0755))
+		src := source.Source{GitHub: &source.GitHubConfig{Owner: "test", Repository: "myplugin"}}
+		url := pluginReleaseURL(pluginDir, "v1.0.0", "v1.1.0", src)
+		assert.Equal(t, "https://github.com/test/myplugin/releases/tag/v1.1.0", url)
+	})
+
+	t.Run("goproxy", func(t *testing.T) {
+		t.Parallel()
+		src := source.Source{GoProxy: &source.GoProxyConfig{Name: "google.golang.org/grpc/cmd/protoc-gen-go-grpc"}}
+		url := pluginReleaseURL("", "", "v1.5.1", src)
+		assert.Equal(t, "https://pkg.go.dev/google.golang.org/grpc/cmd/protoc-gen-go-grpc@v1.5.1", url)
+	})
+
+	t.Run("npm", func(t *testing.T) {
+		t.Parallel()
+		src := source.Source{NPMRegistry: &source.NPMRegistryConfig{Name: "@bufbuild/protoc-gen-es"}}
+		url := pluginReleaseURL("", "", "v2.5.0", src)
+		assert.Equal(t, "https://www.npmjs.com/package/@bufbuild/protoc-gen-es/v/2.5.0", url)
+	})
+
+	t.Run("crates", func(t *testing.T) {
+		t.Parallel()
+		src := source.Source{Crates: &source.CratesConfig{CrateName: "prost"}}
+		url := pluginReleaseURL("", "", "v0.13.4", src)
+		assert.Equal(t, "https://crates.io/crates/prost/0.13.4", url)
+	})
+
+	t.Run("maven", func(t *testing.T) {
+		t.Parallel()
+		src := source.Source{Maven: &source.MavenConfig{Group: "io.grpc", Name: "grpc-java"}}
+		url := pluginReleaseURL("", "", "v1.70.0", src)
+		assert.Equal(t, "https://mvnrepository.com/artifact/io/grpc/grpc-java/1.70.0", url)
+	})
+
+	t.Run("dart_flutter", func(t *testing.T) {
+		t.Parallel()
+		src := source.Source{DartFlutter: &source.DartFlutterConfig{Name: "protobuf"}}
+		url := pluginReleaseURL("", "", "v3.1.0", src)
+		assert.Equal(t, "https://pub.dev/packages/protobuf/versions/3.1.0", url)
+	})
+}
+
+func TestGeneratePRBody(t *testing.T) {
+	t.Parallel()
+
+	t.Run("single plugin with release URLs", func(t *testing.T) {
+		t.Parallel()
+		created := []createdPlugin{
+			{
+				org: "connectrpc", name: "swift",
+				previousVersion:    "v1.2.1",
+				newVersion:         "v1.2.2",
+				previousReleaseURL: "https://github.com/connectrpc/connect-swift/releases/tag/1.2.1",
+				releaseURL:         "https://github.com/connectrpc/connect-swift/releases/tag/1.2.2",
+			},
+		}
+		body := generatePRBody(created)
+		assert.Equal(t, "### connectrpc\n- swift: [v1.2.1](https://github.com/connectrpc/connect-swift/releases/tag/1.2.1) → [v1.2.2](https://github.com/connectrpc/connect-swift/releases/tag/1.2.2)", body)
+	})
+
+	t.Run("single plugin without release URLs", func(t *testing.T) {
+		t.Parallel()
+		created := []createdPlugin{
+			{org: "protocolbuffers", name: "go", previousVersion: "v1.36.5", newVersion: "v1.37.0"},
+		}
+		body := generatePRBody(created)
+		assert.Equal(t, "### protocolbuffers\n- go: v1.36.5 → v1.37.0", body)
+	})
+
+	t.Run("multiple plugins grouped by org", func(t *testing.T) {
+		t.Parallel()
+		created := []createdPlugin{
+			{
+				org: "protocolbuffers", name: "go",
+				previousVersion:    "v1.36.5",
+				newVersion:         "v1.37.0",
+				previousReleaseURL: "https://github.com/protocolbuffers/protobuf-go/releases/tag/v1.36.5",
+				releaseURL:         "https://github.com/protocolbuffers/protobuf-go/releases/tag/v1.37.0",
+			},
+			{
+				org: "protocolbuffers", name: "java",
+				previousVersion:    "v4.28.3",
+				newVersion:         "v4.29.0",
+				previousReleaseURL: "https://github.com/protocolbuffers/protobuf/releases/tag/v4.28.3",
+				releaseURL:         "https://github.com/protocolbuffers/protobuf/releases/tag/v4.29.0",
+			},
+		}
+		body := generatePRBody(created)
+		assert.Equal(t, "### protocolbuffers\n- go: [v1.36.5](https://github.com/protocolbuffers/protobuf-go/releases/tag/v1.36.5) → [v1.37.0](https://github.com/protocolbuffers/protobuf-go/releases/tag/v1.37.0)\n- java: [v4.28.3](https://github.com/protocolbuffers/protobuf/releases/tag/v4.28.3) → [v4.29.0](https://github.com/protocolbuffers/protobuf/releases/tag/v4.29.0)", body)
+	})
+
+	t.Run("empty created list", func(t *testing.T) {
+		t.Parallel()
+		assert.Empty(t, generatePRBody(nil))
+	})
+}
+
 type testWriter struct {
 	tb testing.TB
 }