Support mkdir at mountpoints (#1120)

prelude/bootstrap.js

@@ -453,6 +453,8 @@ function payloadFileSync(pointer) {
   ancestor.exists = fs.exists;
   ancestor.accessSync = fs.accessSync;
   ancestor.access = fs.access;
+  ancestor.mkdirSync = fs.mkdirSync;
+  ancestor.mkdir = fs.mkdir;
 
   var windows = process.platform === 'win32';
 
@@ -1241,6 +1243,40 @@ function payloadFileSync(pointer) {
     accessFromSnapshot(path, callback);
   };
 
+  // ///////////////////////////////////////////////////////////////
+  // mkdir /////////////////////////////////////////////////////////
+  // ///////////////////////////////////////////////////////////////
+
+  function mkdirFailInSnapshot(path_, cb) {
+    var cb2 = cb || rethrow;
+    return cb2(
+      new Error('Cannot mkdir in a snapshot. Try mountpoints instead.')
+    );
+  }
+
+  fs.mkdirSync = function mkdirSync(path) {
+    if (!insideSnapshot(path)) {
+      return ancestor.mkdirSync.apply(fs, arguments);
+    }
+    if (insideMountpoint(path)) {
+      return ancestor.mkdirSync.apply(fs, translateNth(arguments, 0, path));
+    }
+
+    return mkdirFailInSnapshot(path);
+  };
+
+  fs.mkdir = function mkdir(path) {
+    if (!insideSnapshot(path)) {
+      return ancestor.mkdir.apply(fs, arguments);
+    }
+    if (insideMountpoint(path)) {
+      return ancestor.mkdir.apply(fs, translateNth(arguments, 0, path));
+    }
+
+    var callback = dezalgo(maybeCallback(arguments));
+    mkdirFailInSnapshot(path, callback);
+  };
+
   // ///////////////////////////////////////////////////////////////
   // promises ////////////////////////////////////////////////////////
   // ///////////////////////////////////////////////////////////////

test/test-1120-mkdir-mountpoints/main.js

@@ -0,0 +1,27 @@
+#!/usr/bin/env node
+
+'use strict';
+
+const path = require('path');
+const assert = require('assert');
+const utils = require('../utils.js');
+
+assert(!module.parent);
+assert(__dirname === process.cwd());
+
+const target = process.argv[2] || 'host';
+const input = './test-x-index.js';
+const output = './run-time/test-output.exe';
+
+let right;
+utils.mkdirp.sync(path.dirname(output));
+
+utils.pkg.sync(['--target', target, '--output', output, input]);
+
+right = utils.spawn.sync('./' + path.basename(output), [], {
+  cwd: path.dirname(output),
+});
+
+assert.strictEqual(right, 'hello.txt\n');
+
+utils.vacuum.sync(path.dirname(output));

test/test-1120-mkdir-mountpoints/test-x-index.js

@@ -0,0 +1,18 @@
+'use strict';
+
+var fs = require('fs');
+var path = require('path');
+
+var myDirectory = path.dirname(process.execPath);
+
+process.pkg.mount(
+  path.join(__dirname, 'plugins-D-ext'),
+  path.join(myDirectory, 'plugins-D-ext')
+);
+
+fs.mkdirSync('./plugins-D-ext/');
+fs.writeFileSync('./plugins-D-ext/hello.txt', 'hello world!');
+
+console.log(
+  fs.readdirSync(path.join(__dirname, './plugins-D-ext/')).join('\n')
+);