feat: JSONC schema

schema/ValidatingConfiguration.md

@@ -19,8 +19,13 @@ npx ajv-cli validate -s ./markdownlint/schema/markdownlint-config-schema.json -d
 By default, any rule name is valid because of custom rules. To allow only
 built-in rules, use the
 [`markdownlint-config-schema-strict.json`][markdownlint-config-schema-strict]
-JSON Schema instead.
+schema instead.
+
+To allow trailing commas in a JSONC file, use the
+[`markdownlint-config-schema-jsonc.json`][markdownlint-config-schema-jsonc]
+schema instead. (This is based on the strict schema.)
 
 [json-schema]: https://json-schema.org
 [markdownlint-config-schema]: markdownlint-config-schema.json
 [markdownlint-config-schema-strict]: markdownlint-config-schema-strict.json
+[markdownlint-config-schema-jsonc]: markdownlint-config-schema-jsonc.json

schema/build-config-schema.mjs

@@ -12,6 +12,8 @@ const schemaName = "markdownlint-config-schema.json";
 const schemaUri = `https://raw.githubusercontent.com/DavidAnson/markdownlint/v${version}/schema/${schemaName}`;
 const schemaStrictName = "markdownlint-config-schema-strict.json";
 const schemaStrictUri = `https://raw.githubusercontent.com/DavidAnson/markdownlint/v${version}/schema/${schemaStrictName}`;
+const schemaJsoncName = "markdownlint-config-schema-jsonc.json";
+const schemaJsoncUri = `https://raw.githubusercontent.com/DavidAnson/markdownlint/v${version}/schema/${schemaJsoncName}`;
 
 // Schema scaffolding
 const schema = {
@@ -691,6 +693,15 @@ const schemaStrict = {
 const schemaFileStrict = path.join(__dirname(import.meta), schemaStrictName);
 await fs.writeFile(schemaFileStrict, JSON.stringify(schemaStrict, null, "  "));
 
+// Create and write JSONC schema
+const schemaJsonc = {
+  ...schemaStrict,
+  "$id": schemaJsoncUri,
+  "allowTrailingCommas": true
+};
+const schemaFileJsonc = path.join(__dirname(import.meta), schemaJsoncName);
+await fs.writeFile(schemaFileJsonc, JSON.stringify(schemaJsonc, null, "  "));
+
 // Write TypeScript declaration file
 const declarationStrictName = path.join(__dirname(import.meta), "..", "lib", "configuration-strict.d.ts");
 schemaStrict.title = "ConfigurationStrict";