# TypeScript Error Fixes - Progress Report

## Summary

**Initial Errors**: 2,724
**Current Errors**: 2,469
**Fixed**: 255 errors (9.4% reduction)

## Phase 1: Quick Wins - COMPLETED ✅

### 1. Missing Catch Block Parameters (TS2304) - FIXED
Fixed ~50 catch blocks missing error parameter across the codebase:

**Files Fixed**:
- `src/api/auth.ts` - 5 catch blocks
- `src/api/client.ts` - 1 catch block
- `src/components/auth/AuthKitSync.tsx` - 1 catch block
- `src/components/equivalence/ImportWizard.tsx` - 2 catch blocks (changed `err` to `error`)
- `src/components/graph/EquivalenceImport.tsx` - 3 catch blocks
- All form components in `src/components/forms/` - ~15 catch blocks

**Method**: Global find/replace `} catch {` → `} catch (error) {`

### 2. Missing Logger Imports - FIXED
Added logger imports to 36 files that referenced `logger` but didn't import it:

**Import Pattern**: `import { logger } from '@/lib/logger';`

**Files Fixed**:
- Graph components: AggregateGroupNode, ClusterNode, DesignTokenBrowser.example, etc.
- Graph stories: GraphLayoutWorkerDemo, GraphToolbar, etc.
- Temporal stories: BranchExplorer, TemporalNavigator, TimelineView
- Hooks: useConfirmedDelete, useGraphLayoutWorker, useMCP, useQuadTreeCulling, useRealtime, etc.
- Utils: helpers.ts, screenshot.ts, browser.ts
- Workers: graphLayout.worker.ts

**Fixed Import Conflicts**: Corrected 6 files where logger import was inserted mid-import block:
- useMCP.ts, useQuadTreeCulling.ts, edgeBenchmark.ts
- useGraphLayoutWorker.ts, EquivalenceExport.tsx, ThumbnailPreview.tsx
- TemporalNavigator.stories.tsx

## Current Error Breakdown

| Error Code | Count | Description | Priority |
|------------|-------|-------------|----------|
| **TS4111** | 989 | Index signature access (use `obj['prop']`) | **HIGH** |
| **TS2322** | 646 | Type mismatch | **HIGH** |
| **TS6133** | 135 | Unused variables | **MEDIUM** |
| **TS2739** | 118 | Missing properties | **HIGH** |
| **TS2339** | 87 | Property doesn't exist | **HIGH** |
| **TS7006** | 76 | Implicit any parameter | **MEDIUM** |
| **TS2304** | 69 | Cannot find name (remaining) | **HIGH** |
| **TS2532** | 51 | Null safety | **HIGH** |
| **TS18048** | 48 | Possibly undefined | **HIGH** |
| **TS2345** | 45 | Argument type mismatch | **MEDIUM** |
| Other | <250 | Various | **LOW** |

## Phase 2: Remaining High-Priority Fixes

### 1. Index Signature Access (TS4111) - 989 errors ⏳

**Top Files**:
- `src/hooks/useSpecifications.ts` - 171 errors
- `src/hooks/useIntegrations.ts` - 155 errors
- `src/hooks/useTestRuns.ts` - 68 errors
- `src/hooks/useTestCases.ts` - 66 errors
- `src/hooks/useItems.ts` - 65 errors

**Fix Required**: Change `obj.property` → `obj['property']`

**Recommendation**: Bulk fix with careful sed/regex:
```bash
# Pattern to identify: accessing properties on API response objects
# These need bracket notation due to index signatures in OpenAPI types
```

### 2. Type Mismatches (TS2322) - 646 errors ⏳

Requires case-by-case analysis. Common patterns:
- Incorrect return types
- Missing null checks
- Wrong interface implementations

### 3. Unused Variables (TS6133) - 135 errors 🔄

**Fix Required**: Prefix with underscore `_variableName` or remove

**Sample Files**:
- `src/api/streaming.ts` - fetchNDJSON
- `src/api/websocket.ts` - batchSize, startBatching
- Component files with unused props/destructured variables

### 4. Missing Properties (TS2739) - 118 errors ⏳

Common in form components and API responses. Need to:
- Add missing required properties
- Make properties optional if appropriate
- Fix interface definitions

## Next Steps

### Immediate (Can be automated)

1. **Fix TS4111 (Index Signatures)** - 989 errors
   - Create script to convert dot notation to bracket notation
   - Focus on hook files first (useSpecifications, useIntegrations, etc.)
   - Estimated time: 2-3 hours

2. **Fix TS6133 (Unused Variables)** - 135 errors
   - Prefix with underscore or remove
   - Can be partially automated
   - Estimated time: 1 hour

### Manual Review Required

3. **Fix TS2322 (Type Mismatches)** - 646 errors
   - Requires understanding context
   - Fix incorrect type assignments
   - Estimated time: 4-6 hours

4. **Fix TS2739 (Missing Properties)** - 118 errors
   - Add missing properties to objects
   - Update interfaces
   - Estimated time: 2-3 hours

5. **Fix TS2532/TS18048 (Null Safety)** - 99 errors
   - Add null checks
   - Use optional chaining
   - Estimated time: 2-3 hours

## Tools & Scripts Created

1. `/tmp/add-logger-imports.sh` - Adds logger imports to files
2. `/tmp/fix-unused-vars.sh` - Template for fixing unused variables

## Build Status

- **typecheck**: ❌ FAILING (2,469 errors)
- **build**: Not tested (typecheck must pass first)

## Recommendations

1. **Continue with automated fixes first**: Index signatures (TS4111) and unused variables (TS6133) can be largely automated
2. **Use incremental approach**: Fix one file at a time, run typecheck, verify
3. **Consider type assertion strategy**: For API responses with index signatures, consider using type assertions or helper functions
4. **Update OpenAPI codegen**: If possible, improve generated types to avoid index signature issues

## Total Estimated Time Remaining

- Automated fixes: 3-4 hours
- Manual fixes: 8-12 hours
- **Total: 11-16 hours**

---

*Report generated: 2026-02-01*
*Status: Phase 1 Complete, Phase 2 In Progress*
