Cursor rule

1---
2description: "Subagent task: Fix strict TypeScript errors in standalone feature files (batch C) and add to CORE_FILES"
3globs:
4  - "scripts/check-strict-core.js"
5  - "injected/src/features/exception-handler.js"
6  - "injected/src/features/favicon.js"
7  - "injected/src/features/gpc.js"
8  - "injected/src/features/navigator-interface.js"
9  - "injected/src/features/performance-metrics.js"
10---
11 
12# Strict TypeScript: Standalone Features C
13 
14## Task
15 
16Fix all strict-mode TypeScript errors in 5 standalone feature files and add them to `CORE_FILES`.
17 
18## Branch
19 
20```
21git checkout main && git pull origin main && git checkout -b cursor/strict/standalone-features-c
22```
23 
24## Files (13 errors total)
25 
26### `injected/src/features/exception-handler.js` (1 error)
27```
28(7,42): error TS7006: Parameter 'e' implicitly has an 'any' type.
29```
30 
31### `injected/src/features/favicon.js` (3 errors)
32```
33(25,13): error TS7034: Variable 'trailing' implicitly has type 'any'.
34(30,26): error TS7005: Variable 'trailing' implicitly has an 'any' type.
35(109,37): error TS2345: Argument of type '(link: HTMLLinkElement) => ...' is not assignable to parameter of type '(value: Element, ...) => ...'.
36```
37 
38### `injected/src/features/gpc.js` (1 error)
39```
40(5,10): error TS7006: Parameter 'args' implicitly has an 'any' type.
41```
42 
43### `injected/src/features/navigator-interface.js` (6 errors)
44```
45(13,10): error TS7006: Parameter 'args' implicitly has an 'any' type.
46(19,10): error TS7006: Parameter 'args' implicitly has an 'any' type.
47(23,30): error TS7006: Parameter 'args' implicitly has an 'any' type.
48(34,17): error TS2322: Type '(object: object, propertyName: string | symbol, descriptor: StrictPropertyDescriptor) => void' is not assignable to type '<T>(o: T, p: PropertyKey, attributes: PropertyDescriptor & ThisType<any>) => T'.
49(59,40): error TS7053: Element implicitly has an 'any' type (string index on {}).
50(64,17): error TS7053: Element implicitly has an 'any' type (string index on {}).
51```
52 
53### `injected/src/features/performance-metrics.js` (2 errors)
54```
55(50,21): error TS7006: Parameter 'callback' implicitly has an 'any' type.
56(54,26): error TS7006: Parameter 'callback' implicitly has an 'any' type.
57```
58 
59## Fix Patterns
60 
61- **TS7006** (Parameter implicitly any): Add `@param {Type}` JSDoc. For `args`, check parent class.
62- **TS7034/TS7005** (Variable implicitly any): Add explicit `/** @type {X} */` at declaration.
63- **TS2345** (Argument not assignable): In favicon.js, the `Array.from(elements).map(link => ...)` callback expects `Element` but the function types it as `HTMLLinkElement`. Cast inside the callback or use proper generic: `/** @type {HTMLLinkElement[]} */ (Array.from(elements))`.
64- **TS2322** (Type not assignable): In navigator-interface.js, `Object.defineProperty` return type mismatch. May need to cast the wrapped function or adjust the type assertion.
65- **TS7053** (No index signature): Cast config objects to `Record<string, unknown>` or define proper `@typedef`.
66 
67## Workflow
68 
691. `npm ci`
702. Add all 5 files to CORE_FILES in `scripts/check-strict-core.js`
713. Fix each file's errors
724. `npm run tsc-strict-core` — must pass
735. `npm run test-unit` — must pass
746. `npm run lint` — must pass (run `npm run lint-fix` first if needed)
757. Commit: `fix(types): add strict checking for standalone feature files (batch C)`
768. `git push -u origin cursor/strict/standalone-features-c`
77 
78## Constraints
79 
80- Do NOT use `any` — use `unknown`, specific types, or proper interfaces
81- Do NOT use `@ts-ignore` or `@ts-expect-error`
82- Do NOT modify files outside the assigned list (except `scripts/check-strict-core.js`)
83- Do NOT remove existing CORE_FILES entries
84- Preserve existing behavior — type fixes only, no logic changes
85