Trouble with __dirname

[neelance]

My tests have to read (and optionally write) some files relative to the test's .js file. For getting the correct path I used __dirname before switching to mocha-webpack. Now I'm having a hard time making __dirname work. I tried the node.__dirname options in the webpack config, but with no success. Do you have any idea on how to solve this? Mocha-webpack works great otherwise, great job!

[zinserjan]

Seems that there is no way to get this behavior with webpack without doing something special. Webpack replaces the __dirname and __filename with constant strings.

Let's do the same. I modified webpack's NodeStuffPlugin plugin to get the desired effect.

NodePathReplacePlugin.js

/**
 * Modified NodeStuffPlugin to replace __filename and __dirname with absolute path
 * @see https://github.com/webpack/webpack/blob/ca8b693c2c17bd06778476381fae23b3b21c0475/lib/NodeStuffPlugin.js
 */
function NodePathReplacePlugin() {}
module.exports = NodePathReplacePlugin;
NodePathReplacePlugin.prototype.apply = function(compiler) {

    function setModuleConstant(expressionName, fn) {
        compiler.parser.plugin("expression " + expressionName, function() {
            this.state.current.addVariable(expressionName, JSON.stringify(fn(this.state.module)));
            return true;
        });
    }

    setModuleConstant("__filename", function(module) {
        return module.resource;
    });

    setModuleConstant("__dirname", function(module) {
        return module.context;
    });

};

Just require it in your webpack config and add it the plugins sections
webpack-config.js

var NodePathReplacePlugin = require('./NodePathReplacePlugin');

module.exports = {
....
  plugins: [
    new NodePathReplacePlugin()
  ]
....
}

[neelance]

Cool, thanks!

[0xR]

This works indeed!

Can this be part of mocha-webpack itself? That way I don't have to add this plugin I don't quite understand to my codebase.