fix(linter): avoid no-unreachable false positive after conditional loop#22869
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Pull request overview
Fixes an eslint(no-unreachable) false positive where an infinite while (true) inside a conditional branch incorrectly caused code after the conditional to be treated as unreachable, despite an alternate reachable control-flow path (e.g. the if false branch).
Changes:
- Adjusts infinite-loop reachability propagation to avoid overriding blocks that still have a reachable incoming
NormalorJumpedge from outside the infinite-loop exit path. - Adds a regression test covering a conditionally-executed
while (true)that returns, followed by reachable code.
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…op (#22869) `no-unreachable` was treating the normal exit from a `while (true)` loop as making the following block unreachable even when that block also had another reachable incoming path, such as the false branch of an enclosing `if`. This keeps the infinite-loop propagation from overriding blocks that remain reachable through another `Normal` or `Jump` edge, and adds a regression case for a conditionally-run infinite loop that returns inside the loop body. ```mermaid flowchart TD A["enter function"] --> B{"if condition"} B -- true / Jump --> C["while (true)"] C --> D["return inside loop"] D -. "loop normal exit is unreachable" .-> E["statement after if"] B -- false / Jump --> E E["return after if"] --> F["function exit"] classDef reachable fill:#d7f7df,stroke:#1b7f3a,color:#102914; classDef blocked fill:#fde2e2,stroke:#b42318,color:#4a1111; class A,B,C,D,E,F reachable; class D blocked; ``` The key point is that the infinite-loop pass starts from the loop's synthetic normal exit and may mark that path unreachable, but it must stop when the target block has another reachable incoming `Normal` or `Jump` edge. In this case, the post-`if` return is still reachable through the `if` condition's false branch, so reporting it as unreachable is a false positive. fixes #22868
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# Oxlint ### 🚀 Features - e4b1f46 linter/typescript: Implement `method-signature-style` rule (#22679) (Mikhail Baev) - bc462ca linter/vue: Implement no-reserved-component-names rule (#22741) (bab) - ef9e751 linter/vue: Implement component-definition-name-casing rule (#22818) (bab) - d67f51a linter/vue: Implement require-prop-type-constructor rule (#22708) (bab) - 1444f82 linter/promise/spec-only: Add `Promise.try` to `Promise` static methods (#22812) (Ben Saufley) - 8422e8b linter/jsdoc: Implement `require-yields-description` rule (#22805) (Mikhail Baev) - fe93f97 linter/eslint: Implement `prefer-named-capture-group` rule (#22759) (Sebastian Poxhofer) - 1a7798b linter: Add suggestion for `unicorn/no-new-array` (#22682) (Sysix) ### 🐛 Bug Fixes - 760a9f9 linter: Report errors when writing to the filesystem (#22881) (camc314) - e5a2748 linter: Avoid no-unreachable false positive after conditional loop (#22869) (camc314) - 39d92d6 linter/arrow-body-style: Preserve comments within function (#22854) (Sysix) - 3d13e29 parser: Reject `declare` in an already-ambient context (TS1038) (#22850) (Boshen) - 5152854 parser: Reject statements in ambient contexts (TS1036) (#22849) (Boshen) - 2eafea6 parser: Reject function implementations in ambient contexts (TS1183) (#22845) (Boshen) - c645615 parser: Reject incompatible class member modifiers (#22843) (Boshen) - 4a1ca4a linter/export: Detect duplicate explicit exports (#22798) (camc314) - 0a9a735 linter/no-loop-func: Allow safe let closures (#22811) (camc314) - 1599f11 linter: Align lsp extends default plugins (#22788) (camc314) - db32ec9 linter/no-accumulating-spread: Use loop as primary span (#22800) (camc314) - 33ec6b4 linter/consistent-test-it: Avoid adjacent describe leakage (#22796) (camc314) - 2606069 linter/no-array-sort: Unwrap parenthesized sort args (#22794) (camc314) - 9f2f709 linter/no-array-sort: Skip non compare fn sort arguments (#22752) (Gaurav Dubey) - 27268a0 linter/no-else-return: Preserve statement boundary in fixer (#22687) (camc314) - d9cb6d8 linter/no-empty-function: Allow functions callbacks with `allow: functions` (#22764) (camc314) - a40a314 linter/no-shadow-restricted-names: Ignore enum members (#22762) (camc314) - 82366d9 linter/no-cond-assign: Align ternary handling (#22761) (camc314) ### 📚 Documentation - 5e113ba linter: Add license notices for ported ESLint plugins (#22768) (Boshen) # Oxfmt ### 🚀 Features - d75cbbf oxfmt: Format `parser:json` files by `oxc_formatter_json` (#22709) (leaysgur) - 49db054 formatter_json: Implement `oxc_formatter_json` (json variant only) (#22641) (leaysgur) - 9c71f2e ast, codegen, formatter: Add `WithClauseKeyword::as_str` helper and use it (#22791) (camc314) ### 🐛 Bug Fixes - d3cdd62 oxfmt: Skip formatting for whitespace-only file (#22780) (leaysgur) - 23f0cc8 formatter: Don't move comments inside variable declaration in for in loop (#22776) (leaysgur) - f200c40 formatter: Don't move comments inside variable declaration in for of loop (#22773) (Leonabcd123) ### 📚 Documentation - 845f393 oxfmt,formatter,formatter_json,formatter_core: Add/update AGENTS.md (#22873) (leaysgur)
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no-unreachablewas treating the normal exit from awhile (true)loop as making the following block unreachable even when that block also had another reachable incoming path, such as the false branch of an enclosingif.This keeps the infinite-loop propagation from overriding blocks that remain reachable through another
NormalorJumpedge, and adds a regression case for a conditionally-run infinite loop that returns inside the loop body.flowchart TD A["enter function"] --> B{"if condition"} B -- true / Jump --> C["while (true)"] C --> D["return inside loop"] D -. "loop normal exit is unreachable" .-> E["statement after if"] B -- false / Jump --> E E["return after if"] --> F["function exit"] classDef reachable fill:#d7f7df,stroke:#1b7f3a,color:#102914; classDef blocked fill:#fde2e2,stroke:#b42318,color:#4a1111; class A,B,C,D,E,F reachable; class D blocked;The key point is that the infinite-loop pass starts from the loop's synthetic normal exit and may mark that path unreachable, but it must stop when the target block has another reachable incoming
NormalorJumpedge. In this case, the post-ifreturn is still reachable through theifcondition's false branch, so reporting it as unreachable is a false positive.fixes #22868