rollup-plugin-typescript2: Fails with complex usage scenario with `commonjs` and POSIX paths

Apologies for not breaking this down to a minimal reproduction case, but I don’t have time right now and I thought you might be interested in the issue even without the full repro, and that you might understand what the fundamental issue is.

I have a pretty complex Rollup configuration:

module.exports = {
    entry: 'src/host/main.ts',
    dest: 'int/js/mainout.js',
    exports: "none",
    external: [
        "bluebird",
        "power-assert"
    ],
    globals: {
        "bluebird": "Promise",
        "power-assert": "assert"
    },
    useStrict: true,
    sourceMap: true,
    format: "iife",
    plugins: [
        json(),
        typescript({
            typescript: require('typescript'),
        }),
        nodeResolve({
            // use "jsnext:main" if possible
            // – see https://github.com/rollup/rollup/wiki/jsnext:main
            jsnext: true, // Default: false

            // use "main" field or index.js, even if it's not an ES6 module
            // (needs to be converted from CommonJS to ES6
            // – see https://github.com/rollup/rollup-plugin-commonjs
            main: true, // Default: true

            // if there's something your bundle requires that you DON'T
            // want to include, add it to 'skip'
            skip: [],  // Default: []

            // some package.json files have a `browser` field which
            // specifies alternative files to load for people bundling
            // for the browser. If that's you, use this option, otherwise
            // pkg.browser will be ignored
            browser: true, // Default: false

            // not all files you want to resolve are .js files
            extensions: [ '.js', '.json', '.ts' ], // Default: ['.js']
            sourceMap: true,

            // whether to prefer built-in modules (e.g. `fs`, `path`) or
            // local ones with the same names
            preferBuiltins: false // Default: true
        }),
        commonjs({
            extensions: [ '.js', '.ts' ],
            namedExports: {
                "javascript-astar": [ "Graph", "astar" ],
                "screenfull": [ "request" ],
                "marked": ["Renderer","setOptions","parse"],
            }
        }),
        buble({transforms: { dangerousForOf: true, dangerousTaggedTemplateString: true }})
    ]
};

This (mostly) works with the rollup-plugin-typescript plugin, but I thought I’d try this variant of the plugin instead. In part I wanted to try this because the last step above – buble – is not processing the TypeScript helpers injected by rollup-plugin-typescript. Since you’re doing something different, I thought that issue might be solved by switching to this plugin.

But when I switch my include to rollup-plugin-typescript2, I get an error:

Failed to build client-js: Error: Module C:/Users/tim/projects/games/steel/node_modules/javascript-astar/astar.js does not export astar (imported by C:/Users/tim/projects/games/steel/src/common/pathhelper.ts)
    at Module.trace (C:\Users\tim\projects\games\steel\node_modules\rollup\dist\rollup.js:6432:29)
    at C:\Users\tim\projects\games\steel\node_modules\rollup\dist\rollup.js:6006:32
...

This doesn’t even look like it’s in your code, but it doesn’t happen when I run the code through the older plugin, and I don’t have the time to dig down to the root cause here, so I need to fall back on the older plugin. Looking at the TypeScript options you’re setting:

noEmitHelpers: true,
importHelpers: true

… I thought one of these might be causing the problem, but no, when I set those it works using the old plugin. Not only that, but it fixes the problem I was having (because TypeScript is now using the imported helpers which buble correctly).

I have a TypeScript declaration file for javascript-astar, but honestly what it looks like is happening above is not a TypeScript bug but some kind of interaction problem between this plugin and the commonjs plugin (where I specify explicit exports for javascript-astar).

So if I were you and wanted to test this, I’d get an example together that imports some raw JavaScript using the node-resolve and commonjs plugins and see how rollup-plugin-typescript2 might be breaking commonjs.