Agents must have a temp dir of their own, or risk interference with other agents in other threads

Author: rwaldron

.eslintrc.json

@@ -7,7 +7,8 @@
   },
   "extends": "eslint:recommended",
   "parserOptions": {
-    "sourceType": "module"
+    "sourceType": "module",
+    "ecmaVersion": 2017
   },
   "globals": {
     "assert": true,
@@ -16,6 +17,7 @@
     "sinon": true
   },
   "rules": {
-    "no-console": [0]
+    "no-console": [0],
+    "no-empty-pattern": [0]
   }
 }

lib/ConsoleAgent.js

@@ -2,16 +2,27 @@
 const fs = require('fs');
 const path = require('path');
 const cp = require('child_process');
-const temp = require('temp');
 const recast = require('recast');
+const uniqueTempDir = require('unique-temp-dir');
 
-const Agent = require('./Agent.js');
-const ErrorParser = require('./parseError.js');
+const Agent = require('./Agent');
+const ErrorParser = require('./parseError');
 const inception = require('./inception');
-const {getDependencies, hasModuleSpecifier, rawSource} = require('./dependencies.js');
-const writeSources = require('./write-sources.js');
+const writeSources = require('./write-sources');
+const {
+  getDependencies,
+  // escapeModuleSpecifier,
+  hasModuleSpecifier,
+  rawSource
+} = require('./dependencies');
 
 const cpSym = Symbol('cp');
+const tpSym = Symbol('tp');
+
+function generateTempFileName() {
+  const now = Date.now();
+  return `f-${now}-${process.pid}-${(Math.random() * 0x100000000 + 1).toString(36)}.js`;
+}
 
 class ConsoleAgent extends Agent {
   constructor(options) {
@@ -21,6 +32,7 @@ class ConsoleAgent extends Agent {
     // Promise for the child process created by the most
     // recent invocation of `evalScript`
     this[cpSym] = null;
+    this[tpSym] = uniqueTempDir();
   }
 
   createChildProcess(args = [], options = {}) {
@@ -32,8 +44,8 @@ class ConsoleAgent extends Agent {
   }
 
   evalScript(code, options = {}) {
-    let tempfile = temp.path({ suffix: '.js' });
-    let temppath = path.dirname(tempfile);
+    let tempfile = path.join(this[tpSym], generateTempFileName());
+    let temppath = this[tpSym];
 
     let hasDependencies = false;
     let sourcecode;
@@ -113,12 +125,13 @@ class ConsoleAgent extends Agent {
       // 3. Add the prepped source to list of sources that will be written
       //
       dependencies.forEach(file => {
+        let absname = path.join(temppath, file);
         let rawsource = rawSource.get(path.basename(file));
         let jspart = rawsource.split(/\/\*---[\r\n]+[\S\s]*[\r\n]+---\*\//)[1];
 
-        if (path.join(temppath, file) !== tempfile) {
+        if (absname !== tempfile) {
           sources.push([
-            path.join(temppath, file),
+            absname,
             `${preamble}\n${jspart ? jspart : rawsource}`
           ]);
         }

lib/dependencies.js

@@ -4,6 +4,9 @@ const fs = require('fs');
 const path = require('path');
 const rawSourceCache = new Map();
 
+function escapeModuleSpecifier(string) {
+  return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}
 
 function hasModuleSpecifier(source) {
   const dynamicImport = /import\((\s*)('(.+)'|"(.*)")(\s*)\)/g.exec(source);
@@ -73,6 +76,7 @@ function getDependencies(file, accum = []) {
 }
 
 module.exports = {
+  escapeModuleSpecifier,
   getDependencies,
   hasModuleSpecifier,
   rawSource: {

lib/promisify.js

@@ -0,0 +1,14 @@
+module.exports = function(api) {
+  return function(...args) {
+    return new Promise((resolve, reject) => {
+      args.push((error, result) => {
+        if (error) {
+          return reject(error);
+        }
+        return resolve(result);
+      });
+      api(...args);
+    });
+  };
+};
+

lib/write-sources.js

@@ -1,30 +1,37 @@
 'use strict';
 
 const fs = require('fs');
+const path = require('path');
+
+const promisify = require('./promisify');
+const mkdir = promisify(fs.mkdir);
+const stat = promisify(fs.stat);
 const writeFile = promisify(fs.writeFile);
 
-module.exports = function(sources) {
+module.exports = async function(sources) {
+  let {0: [file]} = sources;
+  let dir = path.dirname(file);
+
+  await safeMkdir(dir);
   /*
     first: path to output file
     second: contents
    */
-  return Promise.all(
-    // TODO: Can we use built-in fs-promise?
+  return await Promise.all(
     sources.map(args => writeFile(...args))
   );
 };
 
-function promisify(api) {
-  return function(...args) {
-    return new Promise(function(resolve, reject) {
-      args.push(function(error, result) {
-        if (error) {
-          return reject(error);
-        }
-        return resolve(result);
-      });
-      api(...args);
-    });
-  };
+async function safeMkdir(dir) {
+  try {
+    await stat(dir);
+  } catch (error) {
+    if (error.code === 'ENOENT') {
+      try {
+        await mkdir(dir);
+      } catch ({}) {
+        // suppressed?
+      }
+    }
+  }
 }
-