Webpack ts-loader : change tsconfig filename

Question

I have 2 tsconfigs, one for my dev build and one for my prod build.
I choose the tsconfig with the -p flag :
tsc -p dev.tsconfig.json

Ts-loader is looking for a tsconfig.json file. How can I specify another filename with the ts-loader?

module.exports = {
    entry : __dirname + "/src/app/main.ts",
    output : {
        path : __dirname + "/dist",
        filename : "bundle.js"
    },
   resolve : {
     extensions : ["", ".webpack.js", ".web.js", ".js", ".ts"]
   },
   module: {
        loaders: [
            { test: /\.ts?$/, loader: "ts" }
        ]
    }
};

Answer 1

In Webpack 4 you need to specify the options into a use object:

use: [{
    loader: 'ts-loader',
    options: {
        configFile: "tsconfig.webpack.json"
    }
}]

Complete Webpack config:

var path = require('path');

module.exports = {
    entry: path.resolve(__dirname, 'src') + '/index.ts',
    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'your-library-name.js',
    },
    module: {
        rules: [
            {
                test: /\.ts$/,
                use: [{
                    loader: 'ts-loader',
                    options: {
                        configFile: "tsconfig.webpack.json"
                    }
                }],
                exclude: /node_modules/,
            }
        ]
    },
    mode: 'development',
    resolve: {
        extensions: ['.js', '.ts']
    },
    devtool: false
};