bug(semantic): generic passed to typeof not counted as a reference
#4495
Labels
A-semantic
Area - Semantic
C-bug
Category - Bug
good first issue
Experience Level - Good for newcomers
Comments
DonIsaac
added
C-bug
11 tasks
Dunqing
pushed a commit
that referenced
this issue
Jul 31, 2024
> Re-creation of #4427 due to rebasing issues. Original attempt: #642 ----- Third time's the charm? Each time I attempt this rule, I find a bunch of bugs in `Semantic`, and I expect this attempt to be no different. Expect sidecar issues+PRs stemming from this PR here. ## Not Supported These are cases supported in the original eslint rule, but that I'm intentionally deciding not to support - export comments in scripts ```js /* exported a */ var a; ``` - global comments ```js /* global a */ var a; ``` ## Behavior Changes These are intentional deviations from the original rule's behavior: - logical re-assignments are not considered usages ```js // passes in eslint/no-unused-vars, fails in this implementation let a = 0; a ||= 1; let b = 0; b &&= 2; let c = undefined; c ??= [] ``` ## Known Limitations - Lint rules do not have babel or tsconfig information, meaning we can't determine if `React` imports are being used or not. The relevant tsconfig settings here are `jsx`, `jsxPragma`, and `jsxFragmentName`. To accommodate this, all imports to symbols named `React` or `h` are ignored in JSX files. - References to symbols used in JSDoc `{@link}` tags are not created, so symbols that are only used in doc comments will be reported as unused. See: #4443 - `.vue` files are skipped completely, since variables can be used in templates in ways we cannot detect > note: `.d.ts` files are skipped as well. ## Todo - [x] Skip unused TS enum members on used enums - [x] Skip unused parameters followed by used variables in object/array spreads - [x] Re-assignments to array/object spreads do not respect `destructuredArrayIgnorePattern` (related to: #4435) - [x] #4493 - [x] References inside a nested scope are not considered usages (#4447) - [x] Port over typescript-eslint test cases _(wip, they've been copied and I'm slowly enabling them)_ - [x] Handle constructor properties ```ts class Foo { constructor(public a) {} // `a` should be allowed } ``` - [x] Read references in sequence expressions (that are not in the last position) should not count as a usage ```js let a = 0; let b = (a++, 0); console.log(b) ``` > Honestly, is anyone even writing code like this? - [x] function overload signatures should not be reported - [x] Named functions returned from other functions get incorrectly reported as unused (found by @camc314) ```js function foo() { return function bar() { } } Foo()() ``` - [x] false positive for TS modules within ambient modules ```ts declare global { // incorrectly marked as unused namespace jest { } } ``` ## Blockers - #4436 - #4437 - #4446 - #4447 - #4494 - #4495 ## Non-Blocking Issues - #4443 - #4475 (prevents checks on exported symbols from namespaces)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
The text was updated successfully, but these errors were encountered: