fix: adapt to js-yaml v5 breaking changes

- Add skipLibCheck for Uint8Array<ArrayBuffer> generic type (requires TS 5.7+)
- Replace removed 'replacer' option with pre-dump data transformation

Author: jorgeazevedo

src/riff-raff-yaml-file/index.ts

@@ -270,14 +270,23 @@ export class RiffRaffYamlFile {
    */
   toYAML(riffRaffProjectName: RiffRaffProjectName = UnknownRiffRaffProjectName): string {
     // Add support for ES6 Set and Map. See https://github.com/nodeca/js-yaml/issues/436.
-    const replacer = (_key: string, value: unknown) => {
+    // js-yaml v5 removed the `replacer` option, so we transform the data before dumping.
+    const transformValue = (value: unknown): unknown => {
       if (value instanceof Set) {
-        // eslint-disable-next-line @typescript-eslint/no-unsafe-return -- this is how `js-yaml` is typed
-        return Array.from(value);
+        return Array.from(value).map(transformValue);
       }
       if (value instanceof Map) {
-        // eslint-disable-next-line @typescript-eslint/no-unsafe-return -- this is how `js-yaml` is typed
-        return Object.fromEntries(value);
+        return Object.fromEntries(
+          Array.from(value.entries()).map(([k, v]) => [k, transformValue(v)]),
+        );
+      }
+      if (Array.isArray(value)) {
+        return value.map(transformValue);
+      }
+      if (value !== null && typeof value === "object") {
+        return Object.fromEntries(
+          Object.entries(value).map(([k, v]) => [k, transformValue(v)]),
+        );
       }
       return value;
     };
@@ -288,7 +297,7 @@ export class RiffRaffYamlFile {
       throw new Error(`No Riff-Raff project found with name: ${riffRaffProjectName}`);
     }
 
-    const yaml = dump(content, { replacer });
+    const yaml = dump(transformValue(content));
 
     const comments = [
       "This file was generated by @guardian/cdk, do not edit it directly.",

tsconfig.json

@@ -9,7 +9,8 @@
     "sourceMap": true,
     "inlineSourceMap": false,
     "inlineSources": true,
-    "outDir": "lib"
+    "outDir": "lib",
+    "skipLibCheck": true
   },
   "include": ["src/**/*"],
   "exclude": ["node_modules", "src/**/*.test.ts", "src/**/__snapshots__/**"]