Remove redundant primitive types from intersections #23751
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weswigham
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weswigham
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Looks like a straightforward refactor of TypeIncludes -> TypeFlags plus the small change to simplify intersections. One comment about a typo on the test, though, which may impact that strictNullChecks case.
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| // @strict | |||
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// @strict: true
This isn't setting any compiler options as is and becomes just a comment in the output. Though I guess it's heartening to know that nothing in this change actually relies on strict. 😛
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I don't think so. We have hundreds of tests that include // @strict: true and they definitely behave differently if you remove the comment.
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....this comment isn't // @strict: true, it's just // @strict. This comment does nothing.
src/compiler/checker.ts
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| return includes; | ||
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| function removeRedundantPrimtiveTypes(types: Type[], includes: TypeFlags) { |
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Typo: should be removeRedundantPrimitiveTypes
This PR removes primitive types
string,number, andsymbolfrom intersections that also contain literal types from the same domain. For examplestring & 'a'is reduced to just'a'. Likewise,10 | numberis reduced to just10.The PR eliminates the
TypeIncludesenum from the type checker in favor of just usingTypeFlags. This allows us to more efficiently compute the combined flags during the construction of a union or intersection type.