fix: allow snake_case metadata keys in error catalogs

herodotpb/proto/ory/herodot/v1/herodot.proto

@@ -62,7 +62,7 @@ message ErrorSpec {
   // period, e.g. "The self-service flow has expired. Start a new flow."
   // Values that vary go into metadata, explanations into the comment.
   string message = 2;
-  // The documented ErrorInfo.metadata keys, in lowerCamelCase.
+  // The documented ErrorInfo.metadata keys, matching [a-z][a-zA-Z0-9_-]*.
   repeated string metadata_keys = 3;
 }
 

v2/cmd/protoc-gen-herodot/catalog.go

@@ -22,7 +22,7 @@ import (
 var (
 	domainPattern      = regexp.MustCompile(`^[a-z0-9]([a-z0-9-]*[a-z0-9])?(\.[a-z0-9]([a-z0-9-]*[a-z0-9])?)+$`)
 	reasonPattern      = regexp.MustCompile(`^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$`)
-	metadataKeyPattern = regexp.MustCompile(`^[a-z][a-zA-Z0-9]*$`)
+	metadataKeyPattern = regexp.MustCompile(`^[a-z][a-zA-Z0-9_-]*$`)
 )
 
 const maxReasonLength = 63
@@ -157,7 +157,7 @@ func loadReason(domain string, v *protogen.EnumValue, codes *codeTable) (*reason
 	keys := map[string]bool{}
 	for _, k := range spec.GetMetadataKeys() {
 		if !metadataKeyPattern.MatchString(k) {
-			return nil, fmt.Errorf("metadata key %q is not lowerCamelCase", k)
+			return nil, fmt.Errorf("invalid metadata key %q: must match %s", k, metadataKeyPattern)
 		}
 		if keys[k] {
 			return nil, fmt.Errorf("duplicate metadata key %q", k)

v2/cmd/protoc-gen-herodot/main_test.go

@@ -191,7 +191,7 @@ func TestValidation(t *testing.T) {
 		{"message with surrounding whitespace", map[string]string{"a.proto": catalog("a", "a.com",
 			`X = 1 [(ory.herodot.v1.value).reason = {code: NOT_FOUND, message: "Not found. "}];`)}, "single line"},
 		{"metadata key", map[string]string{"a.proto": catalog("a", "a.com",
-			`X = 1 [(ory.herodot.v1.value).reason = {code: NOT_FOUND, message: "Message.", metadata_keys: ["flow_id"]}];`)}, `metadata key "flow_id" is not lowerCamelCase`},
+			`X = 1 [(ory.herodot.v1.value).reason = {code: NOT_FOUND, message: "Message.", metadata_keys: ["flow.id"]}];`)}, `invalid metadata key "flow.id"`},
 		{"duplicate metadata key", map[string]string{"a.proto": catalog("a", "a.com",
 			`X = 1 [(ory.herodot.v1.value).reason = {code: NOT_FOUND, message: "Message.", metadata_keys: ["a", "a"]}];`)}, `duplicate metadata key "a"`},
 		{"duplicate reason across files", map[string]string{
@@ -326,3 +326,24 @@ func TestOptionImport(t *testing.T) {
 	require.Len(t, response.File, 1)
 	assert.Contains(t, response.File[0].GetContent(), `herodot.Define("keto.ory.com", "NAMESPACE_NOT_FOUND", herodot.CodeNotFound`)
 }
+
+func TestMetadataKeys(t *testing.T) {
+	t.Parallel()
+	for _, key := range []string{"flow_id", "flowId", "flow-id", "a", "limit_per_request", "http2Status"} {
+		t.Run(key, func(t *testing.T) {
+			t.Parallel()
+			source := catalog("a", "a.com", `X = 1 [(ory.herodot.v1.value).reason = {code: NOT_FOUND, message: "Message.", metadata_keys: ["`+key+`"]}];`)
+			out, err := run(t, "lang=json", false, compile(t, map[string]string{"a.proto": source}, "a.proto")...)
+			require.NoError(t, err)
+			assert.Contains(t, out["a.com.errors.json"], `"`+key+`"`)
+		})
+	}
+	for _, key := range []string{"", "FlowId", "1flow", "_flow", "flow.id", "flow id", "flow/id", "flöw"} {
+		t.Run("invalid="+key, func(t *testing.T) {
+			t.Parallel()
+			source := catalog("a", "a.com", `X = 1 [(ory.herodot.v1.value).reason = {code: NOT_FOUND, message: "Message.", metadata_keys: ["`+key+`"]}];`)
+			_, err := run(t, "lang=json", false, compile(t, map[string]string{"a.proto": source}, "a.proto")...)
+			require.ErrorContains(t, err, "invalid metadata key")
+		})
+	}
+}

v2/options.go

@@ -42,9 +42,8 @@ func Cause(err error) Option {
 	return optionFunc(func(d *errorData) { d.cause = err })
 }
 
-// Metadata adds an ErrorInfo metadata entry. Keys are lowerCamelCase and
-// documented in the catalog. A later entry with the same key replaces an
-// earlier one.
+// Metadata adds an ErrorInfo metadata entry. Keys are documented in the catalog.
+// A later entry with the same key replaces the earlier one.
 func Metadata(key, value string) Detail {
 	return metadataDetail{key: key, value: value}
 }