`allowArbitraryExtensions` does not work as expected

[indooorsman]

🔎 Search Terms

allowArbitraryExtensions

🕗 Version & Regression Information

• This is unexpected error from Typescript@5.0

⏯ Playground Link

https://codesandbox.io/p/sandbox/typescript-playground-export-forked-mfz7rg?file=/index.ts:10,28

💻 Code

import {} from "./app.css";

export {};

my tsconfig.json

{
  "compileOnSave": false,
  "compilerOptions": {
    "module": "ESNext",
    "target": "ESNext",
    "lib": [
      "ESNext",
      "DOM",
      "DOM.Iterable"
    ],
    "moduleResolution": "bundler",
    "customConditions": [
      "dev"
    ],
    "jsx": "react-jsx",
    "declaration": true,
    "emitDeclarationOnly": true,
    "isolatedModules": true,
    "strict": true,
    "allowJs": true,
    "skipDefaultLibCheck": true,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "allowArbitraryExtensions": true,
    "allowImportingTsExtensions": true,
    "resolveJsonModule": true,
    "sourceMap": false,
    "rootDirs": [
      "./src",
      "./esm"
    ],
    "outDir": "./esm"
  },
  "include": [
    "./src/**/*"
  ]
}

🙁 Actual behavior

I have set allowArbitraryExtensions to true, but it still throw error when import a .css file.
As mentioned in document:

you can suppress the error with the new --allowArbitraryExtensions compiler option.

🙂 Expected behavior

should not throw error

Additional information about the issue

[MartinJohns]

You're missing the app.d.css.ts file.

[indooorsman]

doesn't it mean any errors about this file with unknown extension would be suppressed ?

…

________________________________ 发件人: Martin Johns ***@***.***> 发送时间: Friday, August 25, 2023 4:23:17 PM 收件人: microsoft/TypeScript ***@***.***> 抄送: indooorsman ***@***.***>; Author ***@***.***> 主题: Re: [microsoft/TypeScript] `allowArbitraryExtensions` does not work as expected (Issue #55507) You're missing the app.d.css.ts file. ― Reply to this email directly, view it on GitHub<#55507 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ABFRA3O73WC455ZKZLSNL2TXXBOHLANCNFSM6AAAAAA355TP4M>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[fatcerberus]

Not sure where you got that idea.

#51435, where this was implemented:

Add --allowArbitraryExtensions, a flag for allowing arbitrary extensions on import paths

And, correspondingly, the .d.ext.ts files needed to describe the shape of whatever it is [you’re] importing.

You still need types for the file you’re importing, as with any other import. The flag just prevents the import from failing on the basis of the file extension alone.

[indooorsman]

Got it, thanks for the explanation

…

________________________________ 发件人: Bruce Pascoe ***@***.***> 发送时间: Friday, August 25, 2023 9:07:30 PM 收件人: microsoft/TypeScript ***@***.***> 抄送: indooorsman ***@***.***>; Author ***@***.***> 主题: Re: [microsoft/TypeScript] `allowArbitraryExtensions` does not work as expected (Issue #55507) Not sure where you got that idea. #51435<#51435>, where this was implemented: Add --allowArbitraryExtensions, a flag for allowing arbitrary extensions on import paths And, correspondingly, the .d.ext.ts files needed to describe the shape of whatever it is [you’re] importing. You still need types for the file you’re importing, as with any other import. The flag just prevents the import from failing on the basis of the file extension alone. ― Reply to this email directly, view it on GitHub<#55507 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ABFRA3MEKW2N4XEXGAZFMALXXCPRFANCNFSM6AAAAAA355TP4M>. You are receiving this because you authored the thread.Message ID: ***@***.***>