Use of import attributes triggers an error incorrectly

[wojtekmaj]

Use of import attributes triggers an error in tsgo (7.0.0-dev.20250528.1), while the latest vintage 😁 TypeScript (5.8.3) does not.

tsconfig.json

{
  "compilerOptions": {
    "isolatedModules": true,
    "lib": ["es2023"],
    "module": "nodenext",
    "moduleDetection": "force",
    "noEmit": true,
    "noUncheckedIndexedAccess": true,
    "resolveJsonModule": true,
    "skipLibCheck": true,
    "strict": true,
    "target": "es2022",
    "verbatimModuleSyntax": true
  }
}

Error:

src/(redacted).ts:3:49 - error TS2856: Import attributes are not allowed on statements that compile to
CommonJS 'require' calls.

3 import redacted from '../data/redacted.json' with { type: 'json' };

Out of curiosity, I changed module to node16 to see if it makes any difference. To my surprise, I got:

src/(redacted).ts:3:49 - error TS2823: Import attributes are only supported when the '--module' option
is set to 'esnext', 'nodenext', or 'preserve'.

...so it suggests me to set module to what it originally was to get rid of the error!

[jakebailey]

Do you have a repo we could test?

[wojtekmaj]

Sure! Here's a minimal repro.

repro.zip

wojciech.maj@MacBook-Pro repro % npm i

added 9 packages, and audited 10 packages in 631ms

found 0 vulnerabilities
wojciech.maj@MacBook-Pro repro % node --run test:strada
wojciech.maj@MacBook-Pro repro % node --run test:corsa 
src/index.ts:1:32 - error TS2856: Import attributes are not allowed on statements that compile to CommonJS 'require' calls.

1 import data from './data.json' with { type: 'json' };
                                 ~~~~~~~~~~~~~~~~~~~~~

Found 1 error in src/index.ts:1

[nf-wbeck]

Setting module to preserve worked to avoid the inconsistent error, though I'm only using tsgo, with separate config, strictly for type checking at the momment; tsc is still used for building.

[wojtekmaj]

Can't reproduce it with the recent version:

PS C:\server> yarn tsc
src/(redacted).ts:3:49 - error TS2856: Import attributes are not allowed on statements that compile to
CommonJS 'require' calls.

3 import redacted from '../data/redacted.json' with { type: 'json' };
                                               ~~~~~~~~~~~~~~~~~~~~~

Found 1 errors in 1 file.

Errors  Files
     2  src/(redacted).ts:3

PS C:\server> yarn up @typescript/native-preview -R
➤ YN0000: · Yarn 4.9.1
➤ YN0000: ┌ Resolution step
➤ YN0085: │ + @typescript/native-preview@npm:7.0.0-dev.20250619.1, and 7 more.
➤ YN0085: │ - @typescript/native-preview-darwin-arm64@npm:7.0.0-dev.20250528.1, and 7 more.
➤ YN0000: └ Completed in 1s 967ms
➤ YN0000: ┌ Fetch step
➤ YN0013: │ 7 packages were added to the project, and 7 were removed (+ 11.24 MiB).
➤ YN0000: └ Completed in 2s 268ms
➤ YN0000: ┌ Link step
➤ YN0008: │ server@workspace:. must be rebuilt because its dependency tree changed
➤ YN0000: └ Completed in 1s 283ms
➤ YN0000: · Done in 5s 610ms
PS C:\server> yarn tsc
PS C:\server>

[jakebailey]

Yes, this was fixed in #1070.