diff --git a/doc/api/cli.markdown b/doc/api/cli.markdown index 52e3f2709c3543..e03773d1e71dd0 100644 --- a/doc/api/cli.markdown +++ b/doc/api/cli.markdown @@ -36,7 +36,8 @@ The output of this option is less detailed than this document. ### `-e`, `--eval "script"` -Evaluate the following argument as JavaScript. +Evaluate the following argument as JavaScript. The modules which are +predefined in the REPL can also be used in `script`. ### `-p`, `--print "script"` diff --git a/lib/internal/bootstrap_node.js b/lib/internal/bootstrap_node.js index 2960234fa08e36..195dfbc0fb89d6 100644 --- a/lib/internal/bootstrap_node.js +++ b/lib/internal/bootstrap_node.js @@ -105,6 +105,9 @@ // User passed '-e' or '--eval' arguments to Node without '-i' or // '--interactive' preloadModules(); + + const internalModule = NativeModule.require('internal/module'); + internalModule.addBuiltinLibsToObject(global); evalScript('[eval]'); } else if (process.argv[1]) { // make process.argv[1] into a full path diff --git a/lib/internal/module.js b/lib/internal/module.js index 9918c73626658a..a12af12f3e3d7e 100644 --- a/lib/internal/module.js +++ b/lib/internal/module.js @@ -1,6 +1,10 @@ 'use strict'; -exports = module.exports = { makeRequireFunction, stripBOM }; +exports = module.exports = { + makeRequireFunction, + stripBOM, + addBuiltinLibsToObject +}; exports.requireDepth = 0; @@ -46,3 +50,47 @@ function stripBOM(content) { } return content; } + +exports.builtinLibs = ['assert', 'buffer', 'child_process', 'cluster', + 'crypto', 'dgram', 'dns', 'domain', 'events', 'fs', 'http', 'https', 'net', + 'os', 'path', 'punycode', 'querystring', 'readline', 'repl', 'stream', + 'string_decoder', 'tls', 'tty', 'url', 'util', 'v8', 'vm', 'zlib']; + +function addBuiltinLibsToObject(object) { + // Make built-in modules available directly (loaded lazily). + exports.builtinLibs.forEach((name) => { + // Goals of this mechanism are: + // - Lazy loading of built-in modules + // - Having all built-in modules available as non-enumerable properties + // - Allowing the user to re-assign these variables as if there were no + // pre-existing globals with the same name. + + const setReal = (val) => { + // Deleting the property before re-assigning it disables the + // getter/setter mechanism. + delete object[name]; + object[name] = val; + }; + + Object.defineProperty(object, name, { + get: () => { + const lib = require(name); + + // Disable the current getter/setter and set up a new + // non-enumerable property. + delete object[name]; + Object.defineProperty(object, name, { + get: () => lib, + set: setReal, + configurable: true, + enumerable: false + }); + + return lib; + }, + set: setReal, + configurable: true, + enumerable: false + }); + }); +} diff --git a/lib/repl.js b/lib/repl.js index 82555497ebf4ba..d802ff304c035a 100644 --- a/lib/repl.js +++ b/lib/repl.js @@ -64,10 +64,7 @@ function hasOwnProperty(obj, prop) { // This is the default "writer" value if none is passed in the REPL options. exports.writer = util.inspect; -exports._builtinLibs = ['assert', 'buffer', 'child_process', 'cluster', - 'crypto', 'dgram', 'dns', 'domain', 'events', 'fs', 'http', 'https', 'net', - 'os', 'path', 'punycode', 'querystring', 'readline', 'stream', - 'string_decoder', 'tls', 'tty', 'url', 'util', 'v8', 'vm', 'zlib']; +exports._builtinLibs = internalModule.builtinLibs; const BLOCK_SCOPED_ERROR = 'Block-scoped declarations (let, ' + @@ -565,23 +562,7 @@ REPLServer.prototype.createContext = function() { this.lines = []; this.lines.level = []; - // make built-in modules available directly - // (loaded lazily) - exports._builtinLibs.forEach((name) => { - Object.defineProperty(context, name, { - get: () => { - var lib = require(name); - this.last = context[name] = lib; - return lib; - }, - // allow the creation of other globals with this name - set: (val) => { - delete context[name]; - context[name] = val; - }, - configurable: true - }); - }); + internalModule.addBuiltinLibsToObject(context); Object.defineProperty(context, '_', { configurable: true, diff --git a/test/parallel/test-cli-eval.js b/test/parallel/test-cli-eval.js index d1db3a815f5df5..a58c023eb6d835 100644 --- a/test/parallel/test-cli-eval.js +++ b/test/parallel/test-cli-eval.js @@ -53,6 +53,13 @@ child.exec(nodejs + ' --eval "require(\'' + filename + '\')"', assert.equal(status.code, 42); }); +// Check that builtin modules are pre-defined. +child.exec(nodejs + ' --print "os.platform()"', + function(status, stdout, stderr) { + assert.strictEqual(stderr, ''); + assert.strictEqual(stdout.trim(), require('os').platform()); + }); + // module path resolve bug, regression test child.exec(nodejs + ' --eval "require(\'./test/parallel/test-cli-eval.js\')"', function(status, stdout, stderr) {