test/cartesian/ReferenceLine/ReferenceLine.spec.tsx (1)

32-36: Missing vi.useFakeTimers() in the test suite.

The coding guidelines require vi.useFakeTimers() in all tests due to Redux autoBatchEnhancer dependency on timers. This beforeEach block doesn't set up fake timers. While this is a pre-existing gap, it's worth addressing since you're already touching this file.

Proposed fix

   beforeEach(() => {
+    vi.useFakeTimers();
     consoleSpy = vi.spyOn(console, 'warn').mockImplementation((): void => undefined);
   });

As per coding guidelines: "Use vi.useFakeTimers() in all tests due to Redux autoBatchEnhancer dependency on timers and requestAnimationFrame"

test/component/Tooltip/Tooltip.multipleDataArrays.spec.tsx (1)

131-132: Hardcoded call index may be stale after the count bump.

Line 132 accesses spy.mock.calls[2][0] — previously this was the last call (count=3), but now with count=4 it's the second-to-last. The test still passes because the scale is identical, but consider using spy.mock.lastCall[0] or spy.mock.calls[spy.mock.calls.length - 1][0] to be resilient to future count changes.

Suggested improvement

       expect(spy).toHaveBeenCalledTimes(4);
-      const scale = spy.mock.calls[2][0];
+      const scale = spy.mock.lastCall[0];

test/state/selectors/selectAxisScale.spec.tsx (1)

40-40: Commented-out assertion reduces render-count verification coverage.

The call-count assertion is commented out instead of being updated to the new expected value. Per coding guidelines, selector call counts should be verified to spot unnecessary re-renders. If the count is now known (e.g., 3 as in the sibling test), update the assertion; otherwise, add a TODO explaining why it's deferred.

Proposed fix

-    // expect(spy).toHaveBeenCalledTimes(3);
+    expect(spy).toHaveBeenCalledTimes(3);

Based on learnings: "Verify the number of selector calls using the spy object from createSelectorTestCase to spot unnecessary re-renders and improve performance"

src/cartesian/CartesianAxis.tsx (2)

339-362: axisId added to TicksProps — verify JSDoc/type documentation.

The axisId field is added to TicksProps without a JSDoc comment. While this is an internal type (not public API), the coding guidelines ask to keep TypeScript definitions up-to-date for documentation purposes. Consider adding a brief comment.

As per coding guidelines: "JSDoc comments and TypeScript definitions in source files must be kept up-to-date as they are used to autogenerate API documentation via 'npm run omnidoc'."

---

45-48: axisId prop added to CartesianAxisProps without JSDoc.

Other props in this interface have comments. A brief JSDoc would be consistent and helpful for the autogenerated API docs.

As per coding guidelines: "JSDoc comments and TypeScript definitions in source files must be kept up-to-date as they are used to autogenerate API documentation via 'npm run omnidoc'."

Suggested addition

   axisType?: 'xAxis' | 'yAxis';
+  /** Unique identifier for this axis instance, used to track rendered ticks in state. */
   axisId?: AxisId;

test/cartesian/XAxis/XAxis.state.spec.tsx (1)

351-372: Missing toHaveBeenCalledTimes assertion on the spy.

The test validates the last-called value but does not verify how many times the selector was invoked. Adding this assertion helps catch unnecessary re-renders.

Proposed fix

     const { spy } = renderTestCase(state => selectRenderedTicksOfAxis(state, 'xAxis', 'foo'));
+    expect(spy).toHaveBeenCalledTimes(3);
     const expectedTicks: ReadonlyArray<TickItem> = [

Based on learnings: "Verify the number of selector calls using the spy object from createSelectorTestCase to spot unnecessary re-renders and improve performance."

src/cartesian/CartesianAxis.tsx (2)

45-49: Missing JSDoc on new axisId prop.

CartesianAxisProps.axisId is a new public-facing prop but lacks a JSDoc comment. As per coding guidelines, JSDoc should be kept up-to-date since it's used for auto-generated API documentation.

Add JSDoc

   axisType?: 'xAxis' | 'yAxis';
+  /**
+   * The unique identifier of the axis this component belongs to.
+   * Used internally to track rendered ticks per axis in the Redux store.
+   */
   axisId?: AxisId;

---

304-337: Potential unnecessary re-dispatches due to unstable ticks reference in the dependency array.

finalTicks is recomputed via getTicks(...) on every render of Ticks, producing a new array reference even when the tick content hasn't changed. This causes the useEffect cleanup + re-dispatch cycle on every render, which will trigger subscribers of the renderedTicks state to re-render as well.

Consider either:

1. Memoizing finalTicks in the Ticks component (e.g., via useMemo with stable inputs), or
2. Doing a shallow comparison of the previous ticks before dispatching inside the effect.

Option 2: Guard dispatch with shallow equality check

 function RenderedTicksReporter({
   ticks,
   axisType,
   axisId,
 }: {
   ticks: ReadonlyArray<TickItemType>;
   axisType: 'xAxis' | 'yAxis' | undefined;
   axisId: AxisId | undefined;
 }) {
   const dispatch = useAppDispatch();
+  const prevTicksRef = useRef<ReadonlyArray<TickItemType> | null>(null);
   useEffect(() => {
     if (axisId == null || axisType == null) {
       return noop;
     }
     // Filter out irrelevant internal properties before exposing externally
     const tickItems = ticks.map(tick => ({
       value: tick.value,
       coordinate: tick.coordinate,
       offset: tick.offset,
       index: tick.index,
     }));
+    // Skip dispatch if ticks haven't meaningfully changed
+    if (
+      prevTicksRef.current != null &&
+      prevTicksRef.current.length === ticks.length &&
+      prevTicksRef.current.every((t, i) => t.value === ticks[i].value && t.coordinate === ticks[i].coordinate)
+    ) {
+      return noop;
+    }
+    prevTicksRef.current = ticks;
     dispatch(setRenderedTicks({ ticks: tickItems, axisId, axisType }));
     return () => {
       dispatch(
         removeRenderedTicks({
           axisId,
           axisType,
         }),
       );
     };
   }, [dispatch, ticks, axisId, axisType]);

   return null;
 }

#!/bin/bash
# Check how finalTicks is produced and whether it could be memoized
rg -n "finalTicks" --type=ts --type=tsx -C3