# bf-34v5a: Extract fixture discovery into standalone module

## Summary
Verified that fixture discovery code is already implemented as a standalone, reusable module at `crates/pdftract-cli/tests/fixture_discovery.rs`.

## Implementation Status

### Module Structure
- **File**: `crates/pdftract-cli/tests/fixture_discovery.rs` (516 lines)
- **Module type**: Standalone Rust module with comprehensive documentation
- **Test coverage**: 13 unit tests, all passing

### Public API Functions
The module provides the following public functions:

1. **`fixtures_root()`** - Returns the root fixtures directory path
2. **`discover_all_fixtures()`** - Recursively discovers all PDF files
3. **`discover_fixtures_by_category(category)`** - Discovers PDFs in a specific category
4. **`discover_fixtures_flat(dir)`** - Non-recursive discovery in a single directory
5. **`discover_fixtures_in_dir(dir)`** - Recursive discovery in a specific directory (internal)
6. **`fixture_categories()`** - Lists all fixture categories present
7. **`fixture_statistics()`** - Returns summary statistics about fixtures

### Usage in Test Code
The module is successfully imported and used by:
- `cli_invocation_fixtures.rs` - Uses `fixtures_root`, `discover_all_fixtures`, `discover_fixtures_by_category`, `discover_fixtures_in_dir`, `fixture_categories`
- `forms_integration.rs` - Uses `fixtures_root`, `discover_fixtures_by_category`, `discover_fixtures_flat`

### Key Features
- Path normalization (handles symlinks, relative paths, absolute paths)
- Recursive and non-recursive discovery modes
- Category-based filtering
- Sorted results for deterministic testing
- Comprehensive test coverage (13 tests)

## Test Results
All 50 tests passed across the fixture discovery ecosystem:
- `fixture_discovery.rs`: 13 tests passed
- `cli_invocation_fixtures.rs`: 18 tests passed
- `forms_integration.rs`: 19 tests passed

## Acceptance Criteria Verification

### ✅ Discovery code is in its own module/file
**Status**: COMPLETE
- File exists at `crates/pdftract-cli/tests/fixture_discovery.rs`
- Well-documented with module-level and function-level docs
- Clean, modular code structure

### ✅ Provides a clear public function for getting PDF fixtures
**Status**: COMPLETE
- Multiple public functions for different discovery needs
- Clear function names: `discover_all_fixtures()`, `discover_fixtures_by_category()`, etc.
- Comprehensive documentation with examples
- Return types are clearly documented (`Vec<PathBuf>`, `FixtureStats`, etc.)

### ✅ Is importable and usable from test code
**Status**: COMPLETE
- Successfully imported via `mod fixture_discovery;` in test files
- Functions imported via `use fixture_discovery::{...}` statements
- No compilation errors or import issues
- Used across multiple test files

## Verification Steps Performed
1. Reviewed `fixture_discovery.rs` implementation
2. Verified public API functions
3. Checked imports in `cli_invocation_fixtures.rs` and `forms_integration.rs`
4. Ran full test suite: 50/50 tests passed
5. Verified module documentation and examples

## Conclusion
The fixture discovery code is already fully extracted into a standalone, reusable module that meets all acceptance criteria. The module provides:
- Clean separation of concerns
- Comprehensive public API
- Full test coverage
- Clear documentation
- Reusable patterns for test code

No code changes were required - the implementation was already complete.

## Files Verified
- `crates/pdftract-cli/tests/fixture_discovery.rs`
- `crates/pdftract-cli/tests/cli_invocation_fixtures.rs`
- `crates/pdftract-cli/tests/forms_integration.rs`

## Test Commands Run
```bash
cargo test --test fixture_discovery --test cli_invocation_fixtures --test forms_integration
```

**Result**: 50/50 tests passed in 0.29s