Fix janoside#442

There was a race condition where multiple frontend requests could be sent trying to retrieve the mining summary data. The first request got the data and cleared it, the second request got an empty response, then encountered an error trying to work with it.

routes/internalApiRouter.js

@@ -203,7 +203,8 @@ router.get("/get-mempool-summary", asyncHandler(async (req, res, next) => {
  delete mempoolSummaryStatuses[statusId];
 
  } else {
- res.json({});
+ res.writeHead(204);
+ res.end("no summary for that id");
 
  next();
  }
@@ -275,7 +276,8 @@ router.get("/get-mining-summary", asyncHandler(async (req, res, next) => {
  delete miningSummaryStatuses[statusId];
 
  } else {
- res.json({});
+ res.writeHead(204);
+ res.end("no summary for that id");
 
  next();
  }

views/mempool-summary.pug

@@ -237,7 +237,7 @@ block endOfBody
  url: `./internal-api/get-mempool-summary?statusId=${statusId}`
 
  }).done((summaryResult) => {
- if (summaryResult.count) {
+ if (summaryResult && summaryResult.count) {
  summary = summaryResult;
 
  $("#json-content").text(JSON.stringify(summaryResult, null, 4));

views/mining-summary.pug

@@ -124,14 +124,15 @@ block endOfBody
  url: `./internal-api/get-mining-summary?statusId=${statusId}`
 
  }).done((summaryResult) => {
- summary = summaryResult;
+ if (summaryResult && summaryResult.overall) {
+ summary = summaryResult;
 
- $("#json-content").text(JSON.stringify(summary, null, 4));
+  $("#json-content").text(JSON.stringify(summary, null, 4));
 
- hljs.highlightAll();
-
- displaySummaryData(summary);
+ hljs.highlightAll();
 
+ displaySummaryData(summary);
+ }
  }).always(() => {
  // nothing
  });