fix(protocol): Fix inline timing metadata parsing and enhance test coverage for performance metrics and timing edge cases

readme.hints.md

@@ -265,4 +265,59 @@ Previously reported issues with these methods have been resolved:
    - Other tests are not executed but still counted
    - Both regular and parallel only tests supported
 
-These fixes ensure accurate test counts and proper TAP-compliant output for all test states.
+These fixes ensure accurate test counts and proper TAP-compliant output for all test states.
+
+## Test Timing Implementation
+
+### Timing Architecture
+
+Test timing is captured using `@push.rocks/smarttime`'s `HrtMeasurement` class, which provides high-resolution timing:
+
+1. **Timing Capture**:
+   - Each `TapTest` instance has its own `HrtMeasurement`
+   - Timer starts immediately before test function execution
+   - Timer stops after test completes (or fails/times out)
+   - Millisecond precision is used for reporting
+
+2. **Protocol Integration**:
+   - Timing is embedded in TAP output using Protocol V2 markers
+   - Inline format for simple timing: `ok 1 - test name ⟦TSTEST:time:123⟧`
+   - Block format for complex metadata: `⟦TSTEST:META:{"time":456,"file":"test.ts"}⟧`
+
+3. **Performance Metrics Calculation**:
+   - Average is calculated from sum of individual test times, not total runtime
+   - Slowest test detection prefers tests with >0ms duration
+   - Failed tests still contribute their execution time to metrics
+
+### Edge Cases and Considerations
+
+1. **Sub-millisecond Tests**:
+   - Very fast tests may report 0ms due to millisecond rounding
+   - Performance metrics handle this by showing "All tests completed in <1ms" when appropriate
+
+2. **Special Test States**:
+   - **Skipped tests**: Report 0ms (not executed)
+   - **Todo tests**: Report 0ms (not executed)
+   - **Failed tests**: Report actual execution time before failure
+   - **Timeout tests**: Report time until timeout occurred
+
+3. **Parallel Test Timing**:
+   - Each parallel test tracks its own execution time independently
+   - Parallel tests may have overlapping execution periods
+   - Total suite time reflects wall-clock time, not sum of test times
+
+4. **Hook Timing**:
+   - `beforeEach`/`afterEach` hooks are not included in individual test times
+   - Only the actual test function execution is measured
+
+5. **Retry Timing**:
+   - When tests retry, only the final attempt's duration is reported
+   - Each retry attempt emits separate `test:started` events
+
+### Parser Fix for Timing Metadata
+
+The protocol parser was fixed to correctly handle inline timing metadata:
+- Changed condition from `!simpleMatch[1].includes(':')` to check for simple key:value pairs
+- Excludes prefixed formats (META:, SKIP:, TODO:, EVENT:) while parsing simple formats like `time:250`
+
+This ensures timing metadata is correctly extracted and displayed in test results.