Fix partial query enabled check and add error handler

lib/middlewares/partial-query.ts

@@ -8,16 +8,22 @@ export interface PartialQueryOptions extends MiddlewareOptions {};
 export function partialJsonQuery(filterString: string) {
   return async (req: NextApiRequest, res: NextApiResponse, next: Function) => {
     const resultBuffer = await getStream.buffer(req.locals.result.data);
-    const resultData = mask(JSON.parse(resultBuffer as any), filterString);
+    // Below code is prone to errors if the body did not contain valid JSON data
+    try {
+      const resultData = mask(JSON.parse(resultBuffer as any), filterString);
 
-    const resultReadable = new Readable();
-    resultReadable.push(JSON.stringify(resultData));
-    resultReadable.push(null);
+      const resultReadable = new Readable();
+      resultReadable.push(JSON.stringify(resultData));
+      resultReadable.push(null);
 
-    req.locals.result = {
-      headers: { 'content-type': 'application/json' },
-      data: resultReadable,
-    };
-    next();
+      req.locals.result = {
+        headers: { 'content-type': 'application/json' },
+        data: resultReadable,
+      };
+    } catch(_) {
+      // Handle errors here if _necessary_ in the future
+    } finally {
+      next();
+    }
   };
 }

pages/api/v1/[..._path].ts

@@ -75,7 +75,7 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
   // Request made
   try {
     const startTime = performance.now();
-    const isPartialQueryEnabled = !!apiRoute.partialQuery.enabled || requestUrl.searchParams.has('diode-filter');
+    const isPartialQueryEnabled = !!apiRoute.partialQuery.enabled && requestUrl.searchParams.has('diode-filter');
     const apiResponse = await axios.request({
       method: apiRoute.method,
       url: requestUrl.toString(),
@@ -95,6 +95,11 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
     req.locals.result = apiResponse;
 
     if (isPartialQueryEnabled && apiResponse.headers['content-type'].includes('application/json')) {
+      /**
+       * get() is used instead of getAll() as only the filter configured
+       * either in dashboard or the incoming query param is used.
+       * Not both to avoid confusion
+       */
       await runMiddleware(req, res, middlewares.partialJsonQuery(requestUrl.searchParams.get('diode-filter')));
     }