Allow ts-loader to be used more than once

[nicojs]

Expected Behaviour

Given this webpack config:

const path = require('path');
module.exports = {
    mode: 'development',
    entry: [
        './src/index.ts',
        './test/index.spec.ts'
    ],
    module: {
        rules: [
            {
                test: /\.ts$/,
                loader: 'ts-loader',
                options: { configFile: 'src/tsconfig.json' },
                include: path.resolve(__dirname, 'src')
            },
            {
                test: /\.ts$/,
                loader: 'ts-loader',
                options: { configFile: 'test/tsconfig.json' },
                include: path.resolve(__dirname, 'test')
            }
        ]
    }
}

I would expect files in the test directory to be transpiled with test/tsconfig.json, while files in the src directory are transpiled using src/tsconfig.json

Actual Behaviour

Both test and src files seems to be transpiled using the src/tsconfig.json file, which results in errors. In my demo application:

ERROR in C:\z\github\nicojs\ts-loader-issue\test\index.spec.ts
./test/index.spec.ts
[tsl] ERROR in C:\z\github\nicojs\ts-loader-issue\test\index.spec.ts(1,1)
      TS2582: Cannot find name 'describe'. Do you need to install type definitions for a test runner? Try `npm i @types/jest` or `npm i @types/mocha`  and then add `jest` or `mocha` to the types field in your tsconfig.

Steps to Reproduce the Problem

1. Create a src/tsconfig.json file and a test/tsconfig.json file.
2. Add the config above in your webpack.conf.js file
3. Install @types/mocha (for example)
4. Add types: [] in src/tsconfig.json, types: ['mocha'] in test/tsconfig.json.
5. Create a file: test/index.spec.ts. Add a call to describe: describe('foo');
6. Run webpack

Location of a Minimal Repository that Demonstrates the Issue.

https://github.com/nicojs/ts-loader-issue

Note: Tried to do this as a workaround for #851

[johnnyreilly]

Does the instance option help at all? https://github.com/TypeStrong/ts-loader/blob/master/README.md#instance-string

[nicojs]

@johnnyreilly thanks for the workaround. It works like a charm:

const path = require('path');
module.exports = {
    mode: 'development',
    entry: [
        './src/index.ts',
        './test/index.spec.ts'
    ],
    module: {
        rules: [
            {
                test: /\.ts$/,
                loader: 'ts-loader',
                options: { instance: 'src', configFile: 'src/tsconfig.json' },
                include: path.resolve(__dirname, 'src')
            },
            {
                test: /\.ts$/,
                loader: 'ts-loader',
                options: { instance: 'test', configFile: 'test/tsconfig.json' },
                include: path.resolve(__dirname, 'test')
            }
        ]
    }
}

Could have been better documented though. I'm also surprised that it had to be explicitly enabled.