internal/labels: switch config to YAML

Switch to YAML from JSON so we can add comments and include
multiline text.

For #64.

Change-Id: Ibbfaf4ec66d8f7bc064d21257943166b26617770
Reviewed-on: https://go-review.googlesource.com/c/oscar/+/636715
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

internal/devtools/cmd/labeleval/main.go

@@ -12,7 +12,7 @@ Usage:
 	labeleval categoryconfig issueconfig
 
 Categoryconfig defines the list of categories to use.
-It is a JSON file that matches the type
+It is a YAML file that matches the type
 
 	struct {
 	  Categories []labels.Category
@@ -34,13 +34,12 @@ There are four results of evaluating an issue:
 A typical run will use the category config from the internal/labels package and the list
 of issues in this package. From repo root:
 
-	go run ./internal/devtools/cmd/labeleval internal/labels/static/categories.json internal/devtools/cmd/labeleval/issues.txt
+	go run ./internal/devtools/cmd/labeleval internal/labels/static/categories.yaml internal/devtools/cmd/labeleval/issues.txt
 */
 package main
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"flag"
 	"fmt"
@@ -61,6 +60,7 @@ import (
 	"golang.org/x/oscar/internal/secret"
 	"golang.org/x/oscar/internal/storage"
 	"golang.org/x/sync/errgroup"
+	"gopkg.in/yaml.v3"
 )
 
 var (
@@ -110,7 +110,7 @@ func run(ctx context.Context, categoryconfigFile, issueConfigFile string) error
 		Categories []labels.Category
 	}
 
-	if err := readJSONFile(categoryconfigFile, &categoryConfig); err != nil {
+	if err := readYAMLFile(categoryconfigFile, &categoryConfig); err != nil {
 		return err
 	}
 	knownCategories := map[string]bool{}
@@ -270,14 +270,14 @@ func newGeminiClient(ctx context.Context, lg *slog.Logger) (*gemini.Client, erro
 	return c, nil
 }
 
-func readJSONFile(filename string, p any) error {
+func readYAMLFile(filename string, p any) error {
 	f, err := os.Open(filename)
 	if err != nil {
 		return err
 	}
 	defer f.Close()
-	dec := json.NewDecoder(f)
-	dec.DisallowUnknownFields()
+	dec := yaml.NewDecoder(f)
+	dec.KnownFields(true)
 	return dec.Decode(p)
 }
 

internal/labels/labels.go

@@ -19,6 +19,7 @@ import (
 
 	"golang.org/x/oscar/internal/github"
 	"golang.org/x/oscar/internal/llm"
+	"gopkg.in/yaml.v3"
 	"rsc.io/markdown"
 )
 
@@ -168,13 +169,14 @@ var config struct {
 var staticFS embed.FS
 
 func init() {
-	f, err := staticFS.Open("static/categories.json")
+	f, err := staticFS.Open("static/categories.yaml")
 	if err != nil {
 		log.Fatal(err)
 	}
 	defer f.Close()
-	dec := json.NewDecoder(f)
-	dec.DisallowUnknownFields()
+
+	dec := yaml.NewDecoder(f)
+	dec.KnownFields(true)
 	if err := dec.Decode(&config); err != nil {
 		log.Fatal(err)
 	}

internal/labels/static/categories.yaml

@@ -0,0 +1,56 @@
+# File of categories used to classify GitHub issues.
+# The category name is distinct from the name of the label used on the issue tracker.
+# The description of a label should match the description on the issue tracker.
+categories:
+  - name: bug
+    label: BUGLABEL
+    description: "Issues describing a bug in the Go implementation."
+  - name: languageProposal
+    label: LANGPROPLABEL
+    description: Issues describing a requested change to the Go language specification.
+  - name: libraryProposal
+    label: LIBPROPLABEL
+    description: Issues describing a requested change to the Go standard library or x/ libraries, but not to a tool
+  - name: toolProposal
+    label: TOOLPROPLABEL
+    description: Issues describing a requested change to a Go tool or command-line program.
+  - name: implementation
+    label: IMPLABEL
+    description: Issues describing a semantics-preserving change to the Go implementation.
+  - name: accessRequest
+    label: accessRequestLABEL
+    description: Issues requesting builder or gomote access.
+  - name: pkgsiteRemovalRequest
+    label: pkgsite/package-removal
+    description: Issues for package removal. See https://pkg.go.dev/about#removing-a-package
+    # We don't label issues posted by gopherbot, so this label is probably unnecessary.
+  - name: automation
+    label: automationLABEL
+    description: Issues created by gopherbot or watchflakes automation.
+  - name: backport
+    label: backportLABEL
+    description: Issues created for requesting a backport of a change to a previous Go version.
+  - name: builders
+    label: Builders
+    description: x/build issues (builders, bots, dashboards)
+  - name: question
+    label: questionLABEL
+    description: Issues that are questions about using Go.
+    # It may be too challenging for the LLM to decide is something is WAI. Consider removing this.
+  - name: workingAsIntended
+    label: WorkingAsIntended
+    description: Issues describing something that is working as it is supposed to.
+  - name: featureRequest
+    label: FeatureRequestLABEL
+    description: Issues asking for a new feature that does not need a proposal.
+  - name: documentation
+    label: Documentation
+    description: Issues describing a change to documentation.
+    # The LLM never seems to pick invalid.
+  - name: invalid
+    label: invalidLABEL
+    description: Issues that are empty, incomplete, or spam.
+    # The LLM never seems to pick other.
+  - name: other
+    label: otherLABEL
+    description: None of the above.