Monorepo example, using @rollup/plugin-alias

[desmap]

What happens and why it is wrong

Environment

I am trying to setup a monorepo with local packages. I am using pnpm workspaces but could also go with tsconfig's paths features. Whatever, I don't get it to work and would love to see an example where somebody gets a monorepo working with this plugin.

My problem is that I get this all the time:

index.ts → index.js...
[!] Error: Unexpected token (Note that you need plugins to import files that are not JavaScript)
../greeter/index.ts (2:6)
1: export default class {
2:   name: string
         ^
3:

note that the imported local package (greeter) has a index.js, index.mjs and index.d.ts file

Versions

• typescript: 3.9.7
• rollup: 2.23
• rollup-plugin-typescript2: 3.1.1

rollup.config.js

import alias from '@rollup/plugin-alias'
import typescript from 'rollup-plugin-typescript2'

module.exports = {
  input: 'index.ts',
  output: {
    file: 'index.js',
    format: 'module',
  },
  plugins: [
    alias({
      entries: [{ find: 'greeter', replacement: '../greeter' }],
    }),
    typescript(),
  ],
}

tsconfig.json

{
  "compilerOptions": {
    "target": "esnext",
    "moduleResolution": "node"
  }
}

package.json

{
  "name": "app",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "type": "module",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "typescript": "^3.9.7"
  },
  "dependencies": {
    "@rollup/plugin-alias": "^3.1.1",
    "greeter": "workspace:^1.0.0",
    "rollup-plugin-typescript2": "^0.27.1",
    "tslib": "^2.0.0"
  }
}

plugin output with verbosity 3

rpt2: built-in options overrides: {
    "noEmitHelpers": false,
    "importHelpers": true,
    "noResolve": false,
    "noEmit": false,
    "inlineSourceMap": false,
    "outDir": "~/test/app/node_modules/.cache/rollup-plugin-typescript2/placeholder",
    "moduleResolution": 2,
    "allowNonTsExtensions": true,
    "module": 5
}
rpt2: parsed tsconfig: {
    "options": {
        "target": 99,
        "moduleResolution": 2,
        "configFilePath": "~/test/app/tsconfig.json",
        "noEmitHelpers": false,
        "importHelpers": true,
        "noResolve": false,
        "noEmit": false,
        "inlineSourceMap": false,
        "outDir": "~/test/app/node_modules/.cache/rollup-plugin-typescript2/placeholder",
        "allowNonTsExtensions": true,
        "module": 5
    },
    "fileNames": [
        "~/test/app/index.ts"
    ],
    "typeAcquisition": {
        "enable": false,
        "include": [],
        "exclude": []
    },
    "raw": {
        "compilerOptions": {
            "target": "esnext",
            "moduleResolution": "node"
        },
        "compileOnSave": false
    },
    "errors": [],
    "wildcardDirectories": {
        "~/test/app": 1
    },
    "compileOnSave": false,
    "configFileSpecs": {
        "includeSpecs": [
            "**/*"
        ],
        "validatedIncludeSpecs": [
            "**/*"
        ],
        "wildcardDirectories": {
            "~/test/app": 1
        }
    }
}
rpt2: typescript version: 3.9.7
rpt2: tslib version: 1.11.2
rpt2: rollup version: 2.23.0
rpt2: rollup-plugin-typescript2 version: 0.27.1
rpt2: plugin options:
{
    "verbosity": 3,
    "check": true,
    "clean": false,
    "cacheRoot": "~/test/app/node_modules/.cache/rollup-plugin-typescript2",
    "include": [
        "*.ts+(|x)",
        "**/*.ts+(|x)"
    ],
    "exclude": [
        "*.d.ts",
        "**/*.d.ts"
    ],
    "abortOnError": true,
    "rollupCommonJSResolveHack": false,
    "useTsconfigDeclarationDir": false,
    "tsconfigOverride": {},
    "transformers": [],
    "tsconfigDefaults": {},
    "objectHashIgnoreUnknownHack": false,
    "cwd": "~/test/app",
    "typescript": "version 3.9.7"
}
rpt2: rollup config:
{
    "external": [],
    "input": "index.ts",
    "plugins": [
        {
            "name": "alias"
        },
        {
            "name": "rpt2"
        },
        {
            "name": "stdin"
        }
    ],
    "output": [
        {
            "file": "index.js",
            "format": "module",
            "plugins": []
        }
    ]
}
rpt2: tsconfig path: ~/test/app/tsconfig.json
rpt2: included:
[
    "*.ts+(|x)",
    "**/*.ts+(|x)"
]
rpt2: excluded:
[
    "*.d.ts",
    "**/*.d.ts"
]
rpt2: ^[[34mAmbient types:^[[39m
rpt2:     ~/test/node_modules/.pnpm/@types/[email protected]/node_modules/@types/estree/index.d.ts
rpt2: ^[[33mambient types changed, redoing all semantic diagnostics^[[39m
rpt2: ^[[34mtranspiling^[[39m '~/test/app/index.ts'
rpt2:     cache: '~/test/app/node_modules/.cache/rollup-plugin-typescript2/rpt2_4a23a64245ad76cbf88c568d3f033c4b438c240a/code/cache/02a6dc8db60bdf18980df68001d986771ff54b6f'
rpt2: ^[[33m    cache miss^[[39m
rpt2:     cache: '~/test/app/node_modules/.cache/rollup-plugin-typescript2/rpt2_4a23a64245ad76cbf88c568d3f033c4b438c240a/syntacticDiagnostics/cache/02a6dc8db60bdf18980df68001d986771ff54b6f'
rpt2: ^[[33m    cache miss^[[39m
rpt2:     cache: '~/test/app/node_modules/.cache/rollup-plugin-typescript2/rpt2_4a23a64245ad76cbf88c568d3f033c4b438c240a/semanticDiagnostics/cache/02a6dc8db60bdf18980df68001d986771ff54b6f'
rpt2: ^[[33m    cache miss^[[39m
rpt2: ^[[34mresolving^[[39m '../greeter' imported by '~/test/app/index.ts'
rpt2:     to '~/test/greeter/index.ts'

[ezolenko]

Could you try setting rollupCommonJSResolveHack option to true. This uses resolve() instead of typescript's resolver. Might cause other problems though.

[desmap]

just tried it but got again:

[!] Error: Unexpected token (Note that you need plugins to import files that are not JavaScript)
../greeter/index.ts (2:6)
1: export default class {
2:   name: string
         ^
3:
4:   greet() {

[desmap]

I think I found the solution:

alias({
  entries: [{ find: 'greeter', replacement: '../greeter/index.mjs' }],
                                                              ^
})

it needs to be ../greeter/index.mjs and not ../greeter nor ../greeter.js (so the "type": "module" didn't help).

Then it compiles flawlessly! I don't know why tho. ;)

[NicolasThierion]

I got the exact same issue, and I think I spotted the issue.
I have the following working directory:

├── packages
│   ├── core
│   │   ├── core.ts
│   │   ├── tsconfig.json
│   │   └──  rollup.config.js
│   └── utils
│       ├── package.json
│       └── utils.ts
├── README.md
├── rollup.config.js
├── tsconfig.json       # compilerOptions.rootDir = '.'
└── package.json

In core.ts, I have the following:

imports `../utils/utils.ts`

To my understanding, compiling core with rollup uses packages/core as the root directory, and automatically excludes any parent directory.

**My fix goes at rollup-plugin-typescript2/src/get-options-overrides.ts: 74 : **
I added a third parameter to createRollupFilter()

return createRollupFilter(included, excluded, { resolve: parsedConfig.options.rootDir });

This way, if compilerOptions.rootDir is specified in tsconfig.json, it is used to create the rollup file filter.

@ezolenko you will find the fix in my PR above.

[ezolenko]

PR is merged, build is in master. Could somebody with this problem verify if it works for them before I do a release?

[ezolenko]

Released in 0.29.0

[NicolasThierion]

Thank you!

[agilgur5]

it needs to be ../greeter/index.mjs and not ../greeter nor ../greeter.js (so the "type": "module" didn't help).

Then it compiles flawlessly! I don't know why tho. ;)

This is probably because at the time of this issue (and even now to some extent), Node's ESM support was not supported by all tooling.

Notably TS 4.7 is the first version of TS to officially support module: "nodenext", and 4.7 is still in beta for that matter (4.5 RC had originally implemented it before deferring it).
So tsc wouldn't have been able to resolve this properly at the time either (not necessarily a bug here then).

I got the exact same issue, and I think I spotted the issue.

As such I believe these are actually two different issues with different root causes -- just similar error messages (this is a very common Rollup error message). So there were kind of two issues in one on this thread, each a different monorepo issue.
Monorepos have other issues too (see the label), so trying to keep track of various issues/root causes/fixes etc.