js-eval: remove h>, simplify stuff

.github/workflows/pull_request.yml

@@ -4,19 +4,14 @@ on: [push, pull_request]
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
 
-    strategy:
-      matrix:
-        node-version: [10.x, 12.x]
-
     steps:
     - uses: actions/checkout@v1
-    - name: Use Node.js ${{ matrix.node-version }}
+    - name: Tests
       uses: actions/setup-node@v1
       with:
-        node-version: ${{ matrix.node-version }}
+        node-version: 15.x
     - name: npm install and test
       run: |
         npm install

src/plugins/js-eval/jsEvalPlugin.js

@@ -1,34 +1,34 @@
 const cp = require('child_process');
+const crypto = require('crypto');
+const { setTimeout } = require('timers/promises');
 const babel = require('@babel/core');
 const babelGenerator = require('@babel/generator').default;
-const jsEval = require('./jsEval');
 const processTopLevelAwait = require('./processTopLevelAwait');
 const { transformPlugins } = require('./babelPlugins');
 
-const helpMsg = `n> node stable, h> node --harmony, b> babel, s> node vm.Script, m> node vm.SourceTextModule, e> engine262`;
-
-// default jseval run command
-const CMD = ['node', '--no-warnings', '/run/run.js'];
-const CMD_SHIMS = [
-  'node',
-  '-r',
-  '/run/node_modules/airbnb-js-shims/target/es2019',
-  '--no-warnings',
-  '/run/run.js',
-];
-const CMD_HARMONY = [
-  'node',
-  '--harmony',
-  '--experimental-vm-modules',
-  '--experimental-modules',
-  '--no-warnings',
-  '/run/run.js',
-];
-
-const jsEvalPlugin = async ({ mentionUser, respond, message, selfConfig = {} }) => {
-  if (!/^[nhbsme?]>/.test(message)) return;
-  const mode = message[0];
+const helpMsg = `n> node stable, b> babel, s> node vm.Script, m> node vm.SourceTextModule, e> engine262`;
+
+const timeoutMs = 5000;
+const envs = {
+  e: 'engine262',
+  s: 'script',
+  m: 'module',
+  n: 'node-cjs',
+  b: 'node-cjs',
+};
+
+module.exports = async function jsEvalPlugin({
+  mentionUser,
+  respond,
+  message,
+  selfConfig = {},
+}) {
+  const mode = message.charAt(0);
+
   if (mode === '?') return respond((mentionUser ? `${mentionUser}, ` : '') + helpMsg);
+
+  if (!envs[mode]) return;
+
   let code = message.slice(2);
 
   const hasMaybeTLA = /\bawait\b/.test(code);
@@ -53,18 +53,56 @@ const jsEvalPlugin = async ({ mentionUser, respond, message, selfConfig = {} })
   }
 
   try {
-    const result = await jsEval(
-      code,
-      mode === 'e'
-        ? 'engine262'
-        : mode === 's'
-        ? 'script'
-        : mode === 'm'
-        ? 'module'
-        : 'node-cjs',
-      selfConfig.timer || 5000,
-      mode === 'b' ? CMD_SHIMS : mode === 'n' ? CMD : CMD_HARMONY,
-    );
+    const name = `jseval-${crypto.randomBytes(8).toString('hex')}`;
+    const args = [
+      'run',
+      '-i',
+      '--rm',
+      `--name=${name}`,
+      `--net=none`,
+      `-eJSEVAL_ENV=${envs[mode]}`,
+      `-eJSEVAL_TIMEOUT=${timeoutMs}`,
+      'brigand/js-eval',
+      'node',
+      '--experimental-vm-modules', // used by m>
+      '--experimental-modules',
+      '--no-warnings',
+      '/run/run.js',
+    ];
+
+    const timeoutCtrl = new AbortController();
+    let data = '';
+
+    const result = await Promise.race([
+      new Promise((resolve, reject) => {
+        const proc = cp.spawn('docker', args);
+
+        proc.stdin.write(code);
+        proc.stdin.end();
+
+        proc.stdout.on('data', (chunk) => {
+          data += chunk;
+        });
+
+        proc.stderr.on('data', (chunk) => {
+          data += chunk;
+        });
+
+        proc.on('error', reject);
+
+        proc.on('exit', (status) => {
+          if (status !== 0) {
+            reject(new Error(data));
+          } else {
+            resolve(data.trim());
+          }
+        });
+      }).finally(() => timeoutCtrl.abort()),
+      setTimeout(timeoutMs + 10, timeoutCtrl).then(() => {
+        cp.execSync(`docker kill --signal=9 ${name}`);
+        throw Object.assign(new Error(data), { reason: 'timeout' }); // send data received so far in the error msg
+      }),
+    ]);
 
     let clean = result.trim();
 
@@ -92,5 +130,3 @@ if (process.env.NODE_ENV !== 'test') {
     });
   });
 }
-
-module.exports = jsEvalPlugin;

src/plugins/js-eval/run.js

@@ -1,12 +1,11 @@
 const { Script, SourceTextModule, createContext } = require('vm');
 const util = require('util');
 const builtinModules = require('module').builtinModules.filter(
-  (a) => !/^_|\//.test(a),
+  (s) => !/^_|\//.test(s),
 );
+const { setTimeout } = require('timers/promises');
 
-const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
-
-// copied from https://github.com/devsnek/docker-js-eval/run.js
+// code taken from https://github.com/devsnek/docker-js-eval/run.js
 
 const inspect = (val) => {
   try {
@@ -46,7 +45,7 @@ function exposeBuiltinInGlobal(name) {
   });
 }
 
-const run = async (code, environment, timeout) => {
+async function run(code, environment, timeout) {
   switch (environment) {
     case 'node-cjs': {
       const script = new Script(code);
@@ -71,18 +70,14 @@ const run = async (code, environment, timeout) => {
         throw new Error('Unable to resolve import');
       });
 
-      const [error, result] = await Promise.race([
-        module.evaluate({ timeout }).then((r) => [null, r]),
-        delay(Math.floor(timeout * 1.5)).then(() => [
-          new Error('The execution timed out'),
-          null,
-        ]),
+      const timeoutCtrl = new AbortController();
+      const result = await Promise.race([
+        module.evaluate({ timeout }).finally(() => timeoutCtrl.abort()),
+        setTimeout(Math.floor(timeout * 1.5), timeoutCtrl).then(() => {
+          throw new Error('The execution timed out');
+        }),
       ]);
 
-      if (error) {
-        throw error;
-      }
-
       return inspect(result);
     }
 
@@ -136,9 +131,9 @@ const run = async (code, environment, timeout) => {
     default:
       throw new RangeError(`Invalid environment: ${environment}`);
   }
-};
+}
 
-if (!module.parent) {
+if (require.main === module) {
   (async () => {
     let code = process.argv[2];
     if (!code) {

src/plugins/mdn/mdnPlugin.js

@@ -72,8 +72,8 @@ async function fixLanguage(origRes, lastRedirect) {
 
 async function fixRedirect(res) {
   const $ = cheerio.load(res.text);
-  const meta = $('meta[http-equiv="refresh"]').attr("content")
-  const reg = /url=\/l\/\?uddg=(.*)/
+  const meta = $('meta[http-equiv="refresh"]').attr('content');
+  const reg = /url=\/l\/\?uddg=(.*)/;
   const match = meta.match(reg);
   if (!match) {
     return res;