# bf-3qpih: Write passing test case for assert_exit_code

## Summary

Verified that the passing test case for `assert_exit_code` already exists in the codebase at `/home/coding/pdftract/crates/pdftract-core/src/extract.rs:3070-3099`.

## Test Details

**Test Name:** `test_extraction_result_assert_exit_code_success`

**Location:** `crates/pdftract-core/src/extract.rs:3070-3099`

**Test Logic:**
1. Creates an `ExtractionResult` with `error_count = 0` (which corresponds to exit code 0)
2. Calls `assert_exit_code(0)` 
3. Asserts that the result is `Ok(())` using `assert!(result.assert_exit_code(0).is_ok())`

**Test Code:**
```rust
#[test]
fn test_extraction_result_assert_exit_code_success() {
    // Test that assert_exit_code returns Ok(()) when exit codes match
    let result = ExtractionResult {
        fingerprint: "test".to_string(),
        pages: vec![],
        metadata: ExtractionMetadata {
            page_count: 0,
            receipts_mode: ReceiptsMode::Off,
            span_count: 0,
            block_count: 0,
            cache_status: None,
            cache_age_seconds: None,
            error_count: 0,
            reading_order_algorithm: None,
            diagnostics: vec![],
            profile_name: None,
            profile_version: None,
            profile_fields: None,
        },
        signatures: vec![],
        form_fields: vec![],
        links: vec![],
        attachments: vec![],
        threads: vec![],
        javascript_actions: vec![],
    };

    // Should succeed - extraction with no errors should have exit code 0
    assert!(result.assert_exit_code(0).is_ok());
}
```

## Verification

Ran the test to confirm it passes:
```bash
cargo nextest run -p pdftract-core test_extraction_result_assert_exit_code_success --no-capture
```

**Result:** ✓ PASS

```
running 1 test
test extract::tests::test_extraction_result_assert_exit_code_success ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 2902 filtered out; finished in 0.00s
```

## Acceptance Criteria Status

- [x] Test case exists for passing scenario
- [x] Test creates ExtractionResult with exit code 0 (via error_count = 0)
- [x] Test calls assert_exit_code(0) and expects Ok(())
- [x] Test passes when run
- [x] Test follows existing test patterns in the codebase

## Additional Context

The test follows the standard pattern for assertion method tests in the codebase:
- Uses `#[test]` attribute
- Includes descriptive comment explaining what is being tested
- Creates test fixtures inline with struct literal syntax
- Uses `assert!(...)` macro for simple boolean assertions
- Follows naming convention: `test_<module>_<method>_<scenario>`

Related tests that also exist:
- `test_extraction_result_assert_exit_code_mismatch` - tests failure case
- `test_extraction_result_assert_exit_code_with_errors` - tests exit code 1 for extractions with errors

## Implementation Method

The `assert_exit_code` method implementation is at `/home/coding/pdftract/crates/pdftract-core/src/extract.rs:2719-2736`. It computes the exit code based on `error_count` (0 for success, 1 for any errors) and returns `Ok(())` when the actual exit code matches the expected value.

## Conclusion

All acceptance criteria are met. The passing test case for `assert_exit_code` is already implemented and functional.