fix(client): pass logs incrementally from test worker

client/src/client/workers/test-evaluator.js

@@ -2,14 +2,38 @@ import chai from 'chai';
 import '@babel/polyfill';
 import __toString from 'lodash/toString';
 
-const oldLog = self.console.log.bind(self.console);
-self.console.log = function proxyConsole(...args) {
-  self.postMessage({
-    type: 'LOG',
-    data: args.map(arg => JSON.stringify(arg)).join(' ')
-  });
-  return oldLog(...args);
-};
+const __utils = (() => {
+  const MAX_LOGS_SIZE = 64 * 1024;
+
+  let logs = [];
+  function flushLogs() {
+    if (logs.length) {
+      self.postMessage({
+        type: 'LOG',
+        data: logs.join('\n')
+      });
+      logs = [];
+    }
+  }
+
+  const oldLog = self.console.log.bind(self.console);
+  self.console.log = function proxyConsole(...args) {
+    logs.push(args.map(arg => JSON.stringify(arg)).join(' '));
+    if (logs.join('\n').length > MAX_LOGS_SIZE) {
+      flushLogs();
+    }
+    return oldLog(...args);
+  };
+
+  function postResult(data) {
+    flushLogs();
+    self.postMessage(data);
+  }
+
+  return {
+    postResult
+  };
+})();
 
 self.onmessage = async e => {
   /* eslint-disable no-unused-vars */
@@ -38,11 +62,11 @@ self.onmessage = async e => {
     if (typeof testResult === 'function') {
       await testResult(fileName => __toString(e.data.sources[fileName]));
     }
-    self.postMessage({
+    __utils.postResult({
       pass: true
     });
   } catch (err) {
-    self.postMessage({
+    __utils.postResult({
       err: {
         message: err.message,
         stack: err.stack

client/src/templates/Challenges/redux/index.js

@@ -215,6 +215,8 @@ export const challengeDataSelector = state => {
   return challengeData;
 };
 
+const MAX_LOGS_SIZE = 64 * 1024;
+
 export const reducer = handleActions(
   {
     [types.fetchIdToNameMapComplete]: (state, { payload }) => ({
@@ -259,19 +261,17 @@ export const reducer = handleActions(
     }),
     [types.initLogs]: state => ({
       ...state,
-      logsOut: []
+      logsOut: ''
     }),
     [types.updateLogs]: (state, { payload }) => ({
       ...state,
-      logsOut: [...state.logsOut, payload]
+      logsOut: (state.logsOut + '\n' + payload).slice(-MAX_LOGS_SIZE)
     }),
     [types.logsToConsole]: (state, { payload }) => ({
       ...state,
       consoleOut:
         state.consoleOut +
-        (state.logsOut.length
-          ? '\n' + payload + '\n' + state.logsOut.join('\n')
-          : '')
+        (state.logsOut ? '\n' + payload + '\n' + state.logsOut : '')
     }),
     [types.updateChallengeMeta]: (state, { payload }) => ({
       ...state,