fix: add TypeScript decorator support to SWC transform #757
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Enable decorator parsing in SWC configuration to support codebases using TypeScript decorators (TypeORM, NestJS, class-validator, custom decorators). Without this fix, projects importing files with decorators fail with: "Unexpected token `@`. Expected identifier..." syntax errors. Changes: - Add `decorators: true` to parser options for TypeScript and ECMAScript - Add `legacyDecorator: true` for TypeScript's experimentalDecorators - Add `decoratorMetadata: true` for emitDecoratorMetadata support
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@technopahadi is attempting to deploy a commit to the Vercel Labs Team on Vercel. A member of the Team first needs to authorize it. |
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Fixes #756 |
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ijjk
reviewed
Jan 10, 2026
Read experimentalDecorators and emitDecoratorMetadata from tsconfig.json to match Next.js behavior. Decorators are now only enabled when explicitly configured in the project's tsconfig. - Add getDecoratorOptionsForDirectory() to read tsconfig settings - Update applySwcTransform and Next.js loader to use tsconfig options - Handle JSONC format (comments, trailing commas) in tsconfig parsing
ijjk
reviewed
Jan 10, 2026
Replace manual regex-based JSONC parsing with json5 library for more robust handling of comments and trailing commas in tsconfig.json files.
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ijjk
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Jan 12, 2026
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@technopahadi could you commit the sign-off from here https://github.com/vercel/workflow/pull/757/checks?check_run_id=60157121285 |
ijjk
approved these changes
Jan 12, 2026
I, Rishabh <rishabh.pugalia@gmail.com>, hereby add my Signed-off-by to this commit: e2f9304 I, Rishabh <rishabh.pugalia@gmail.com>, hereby add my Signed-off-by to this commit: 3faee5d I, Rishabh <rishabh.pugalia@gmail.com>, hereby add my Signed-off-by to this commit: 9dbbda6 Signed-off-by: Rishabh <rishabh.pugalia@gmail.com>
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@ijjk Done |
VaguelySerious
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Jan 16, 2026
* fix: add TypeScript decorator support to SWC transform Enable decorator parsing in SWC configuration to support codebases using TypeScript decorators (TypeORM, NestJS, class-validator, custom decorators). Without this fix, projects importing files with decorators fail with: "Unexpected token `@`. Expected identifier..." syntax errors. Changes: - Add `decorators: true` to parser options for TypeScript and ECMAScript - Add `legacyDecorator: true` for TypeScript's experimentalDecorators - Add `decoratorMetadata: true` for emitDecoratorMetadata support * fix: conditionally enable decorators based on tsconfig compilerOptions Read experimentalDecorators and emitDecoratorMetadata from tsconfig.json to match Next.js behavior. Decorators are now only enabled when explicitly configured in the project's tsconfig. - Add getDecoratorOptionsForDirectory() to read tsconfig settings - Update applySwcTransform and Next.js loader to use tsconfig options - Handle JSONC format (comments, trailing commas) in tsconfig parsing * fix: use json5 for parsing tsconfig in decorator options Replace manual regex-based JSONC parsing with json5 library for more robust handling of comments and trailing commas in tsconfig.json files. * bump * apply fix * DCO Remediation Commit for JJ Kasper <jj@jjsweb.site> I, JJ Kasper <jj@jjsweb.site>, hereby add my Signed-off-by to this commit: aa1dc36 I, JJ Kasper <jj@jjsweb.site>, hereby add my Signed-off-by to this commit: e25f174 Signed-off-by: JJ Kasper <jj@jjsweb.site> * DCO Remediation Commit for Rishabh <rishabh.pugalia@gmail.com> I, Rishabh <rishabh.pugalia@gmail.com>, hereby add my Signed-off-by to this commit: e2f9304 I, Rishabh <rishabh.pugalia@gmail.com>, hereby add my Signed-off-by to this commit: 3faee5d I, Rishabh <rishabh.pugalia@gmail.com>, hereby add my Signed-off-by to this commit: 9dbbda6 Signed-off-by: Rishabh <rishabh.pugalia@gmail.com> --------- Signed-off-by: JJ Kasper <jj@jjsweb.site> Signed-off-by: Rishabh <rishabh.pugalia@gmail.com> Co-authored-by: JJ Kasper <jj@jjsweb.site>
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Enable decorator parsing in SWC configuration to support codebases using
TypeScript decorators (TypeORM, NestJS, class-validator, custom decorators).
Without this fix, projects importing files with decorators fail with:
"Unexpected token
@. Expected identifier..." syntax errors.Changes:
decorators: trueto parser options for TypeScript and ECMAScriptlegacyDecorator: truefor TypeScript's experimentalDecoratorsdecoratorMetadata: truefor emitDecoratorMetadata support