[optimizer] validate the syntax of bundled node_modules #59972
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| export const checks: DisallowedSyntaxCheck[] = [ | ||
| /** | ||
| * es2015 | ||
| */ | ||
| // https://github.com/estree/estree/blob/master/es2015.md#functions | ||
| { | ||
| name: '[es2015] generator function', | ||
| nodeType: ['FunctionDeclaration', 'FunctionExpression'], | ||
| test: (n: estree.FunctionDeclaration | estree.FunctionExpression) => !!n.generator, |
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I would be surprised if we were to be the first project to have such needs. Isn't there no oss tools performing such checks atm?
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I looked around and didn't find anything, but I would be shocked if we could find something that would integrate with the webpack parser so tightly in order to avoid parsing the bundles all over again.
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Yea, from a quick glance, every webpack plugin integration (ie https://github.com/bitjourney/check-es-version-webpack-plugin/blob/master/index.js) are also using acorn at the end and parses the whole files again. None are doing the fine-grained checks you implemented though.
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Co-authored-by: spalger <spalger@users.noreply.github.com> Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com> # Conflicts: # renovate.json5
Co-authored-by: spalger <spalger@users.noreply.github.com> Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com> # Conflicts: # renovate.json5
Fixes #59833
In order to avoid including node_modules in the bundles that break IE compatibility (something that has been plaguing us lately) this webpack plugin checks the AST created by webpack for each node_module being included in the dll.
It does this using
acorn-walk, a module developed by the authors of the default parser webpack uses, to traverse all the nodes in the AST. The nodes are checked against theDisallowedSyntaxCheckobjects defined insrc/optimize/dynamic_dll_plugin/disallowed_syntax.ts. These checks are based on the syntax definitions described by https://github.com/estree/estree, the specification for the AST produced by acorn.Each
SyntaxCheckcan be triggered for one or moreestree.Node['type']. When a node of these types is found and either the check has notestmethod, or the test method returns true, then we throw an error indicating that the disallowed syntax was discovered in the node_module. This triggers webpack to report the module as failing to parse:Performance
In order to reduce the performance impact of this check, the validation is performed on the same AST that webpack is already generating. When switching between this branch and master (with an import in place to make sure the DLL needs to be rebuilt) I'm not seeing any meaningful difference in optimizer execution time.