feat(test-framework): add infinite loop protection (#42)

package.json

@@ -4,9 +4,11 @@
   "private": true,
   "dependencies": {
     "axios": "^0.17.1",
+    "babel-standalone": "^6.26.0",
     "codemirror": "^5.31.0",
     "jshint": "^2.9.5",
     "lodash": "^4.17.4",
+    "loop-protect": "^2.1.6",
     "react": "16.2.0",
     "react-codemirror2": "^3.0.7",
     "react-dom": "^16.0.0",

src/utils/regexp.js

@@ -2,4 +2,4 @@
 export const RESET_STATE = new RegExp('resetState\\(\\)')
 export const SUPPRESS_TESTS = new RegExp('\\/\\/\\s\\s?SUPPRESS\\s\\s?TESTS', 'i')
 export const DO_NOT_SAVE = new RegExp('\\/\\/\\s\\s?DO\\s\\s?NOT\\s\\s?SAVE', 'i')
-export const ERROR_TYPES = new RegExp('tests failed|WARNING:|Fail:|AssertionError|InternalError|RangeError|ReferenceError|EvalError|SyntaxError|TypeError|URIError')
+export const ERROR_TYPES = new RegExp('tests failed|WARNING:|Fail:|AssertionError|InternalError|RangeError|ReferenceError|EvalError|SyntaxError|TypeError|URIError|Error')

src/utils/test/challenge/eval-code-run-tests.js

@@ -1,8 +1,7 @@
 import executeTests from './execute-tests'
 import { SUPPRESS_TESTS } from '../../regexp'
 import TESTS from '../../../assets/testRef'
-
-// TODO: remove check for tests once all challenges have tests
+import loopProtect from './loop-protect'
 
 export default (code, id) => {
   try {
@@ -21,10 +20,10 @@ export default (code, id) => {
       tests = prepend + JSON.stringify(TESTS[id].tests)
       if (TESTS[id].tail) tail += TESTS[id].tail
     }
-
+    
     // eslint-disable-next-line
     eval(
-      code +
+      loopProtect(code) +
       tail +
       tests +
       executeTests

src/utils/test/challenge/loop-protect.js

@@ -0,0 +1,19 @@
+export default (code) => {
+  const timeout = 500
+  const Babel = require('babel-standalone')
+  const protect = require('loop-protect')
+
+  Babel.registerPlugin('loopProtection', protect(timeout))
+  const transform = source => Babel.transform(source, {
+    plugins: ['loopProtection'],
+  }).code
+
+  const error = `Error('Timed out after ${timeout}ms due to an infinite loop. Check your code and try again.')`
+  const _this = new RegExp(`if \\(Date\\.now\\(\\) - _LP > ${timeout}\\)\\s+break;`)
+  const withThis = `if (Date.now() - _LP > ${timeout}) throw new ${error}`
+
+  // use babel and loop-protect to transform user code
+  // into protected loops. Instead of simply breaking the
+  // loop, add replacement logic to throw error to warn user
+  return transform(code).replace(_this, withThis)
+}

yarn.lock

@@ -919,6 +919,10 @@ babel-runtime@6.26.0, babel-runtime@^6.18.0, babel-runtime@^6.22.0, babel-runtim
     core-js "^2.4.0"
     regenerator-runtime "^0.11.0"
 
+babel-standalone@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-standalone/-/babel-standalone-6.26.0.tgz#15fb3d35f2c456695815ebf1ed96fe7f015b6886"
+
 babel-template@^6.16.0, babel-template@^6.24.1, babel-template@^6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-template/-/babel-template-6.26.0.tgz#de03e2d16396b069f46dd9fff8521fb1a0e35e02"
@@ -4032,6 +4036,10 @@ longest@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/longest/-/longest-1.0.1.tgz#30a0b2da38f73770e8294a0d22e6625ed77d0097"
 
+loop-protect@^2.1.6:
+  version "2.1.6"
+  resolved "https://registry.yarnpkg.com/loop-protect/-/loop-protect-2.1.6.tgz#03840f79591121c37a53a87fb9aff2841e488c2d"
+
 loose-envify@^1.0.0, loose-envify@^1.1.0, loose-envify@^1.3.1:
   version "1.3.1"
   resolved "https://registry.yarnpkg.com/loose-envify/-/loose-envify-1.3.1.tgz#d1a8ad33fa9ce0e713d65fdd0ac8b748d478c848"