[compiler] More precise errors for invalid import/export/namespace statements #33748
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This was referenced Jul 9, 2025
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| reason: `The 'eval' function is not supported`, | ||
| description: | ||
| 'Eval is an anti-pattern in JavaScript, and the code executed cannot be evaluated by React Compiler', | ||
| severity: ErrorSeverity.InvalidJS, |
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might be a nit, but should we make a new severity category for eval? It's not technically invalid JS but more something that we can't statically analyze, so maybe a new category would be more accurate. Super minor though.
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Yeah i was on the fence about this. I'll add an UnsupportedJS variant.
This was referenced Jul 9, 2025
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) * Error for `eval()` * More specific error message for `with (expr) { ... }` syntax * More specific error message for class declarations --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33746). * #33752 * #33751 * #33750 * #33748 * #33747 * __->__ #33746
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Supports inline enum declarations in both Flow and TS by treating the node as pass-through (enums can't capture values mutably). Related, this PR extends the set of type-related declarations that we ignore. Previously we threw a todo for things like DeclareClass or DeclareVariable, but these are type related and can simply be dropped just like we dropped TypeAlias. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33747). * #33753 * #33752 * #33751 * #33750 * #33748 * __->__ #33747
…atements import, export, and TS namespace statements can only be used at the top-level of a module, which is enforced by parsers already. Here we add a backup validation of that. As of this PR, we now have only major statement type (class declarations) listed as a todo.
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We use this variant for syntax we intentionally don't support: with statements, eval, and inline class declarations. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33750). * #33753 * #33752 * #33751 * __->__ #33750 * #33748
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) * Error for `eval()` * More specific error message for `with (expr) { ... }` syntax * More specific error message for class declarations --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33746). * #33752 * #33751 * #33750 * #33748 * #33747 * __->__ #33746 DiffTrain build for [4a3ff8e](4a3ff8e)
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) * Error for `eval()` * More specific error message for `with (expr) { ... }` syntax * More specific error message for class declarations --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33746). * #33752 * #33751 * #33750 * #33748 * #33747 * __->__ #33746 DiffTrain build for [4a3ff8e](4a3ff8e)
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We use this variant for syntax we intentionally don't support: with statements, eval, and inline class declarations. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33750). * #33753 * #33752 * #33751 * __->__ #33750 * #33748 DiffTrain build for [96c61b7](96c61b7)
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We use this variant for syntax we intentionally don't support: with statements, eval, and inline class declarations. --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33750). * #33753 * #33752 * #33751 * __->__ #33750 * #33748 DiffTrain build for [96c61b7](96c61b7)
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import, export, and TS namespace statements can only be used at the top-level of a module, which is enforced by parsers already. Here we add a backup validation of that. As of this PR, we now have only major statement type (class declarations) listed as a todo.
Stack created with Sapling. Best reviewed with ReviewStack.