fix: Fix scalar variables not applying after re-selecting a part colored by a vector component

doc/changelog.d/162.fixed.md

@@ -0,0 +1 @@
+Fix scalar variables not applying after re-selecting a part colored by a vector component

src/ansys/visor/visor-client/src/aggregate/AggregateVariableInfo.tsx

@@ -84,15 +84,11 @@ export class AggregateVariableInfo {
 
         for (let i = 0; i < actorNodes.length; i++) {
             const node = actorNodes[i];
-            const variable = node.variableCollection.getVariable(variableInfo.id);
-            let thisComponentId: number | null = node.variableComponent;
-
-            if (variable != null) {
-                if (variable.getRangeInfo(node.variableComponent) == null) {
-                    // Default to the first component option.
-                    thisComponentId = variable.componentOptions[0].id;
-                }
-            }
+            const thisComponentId = AggregateVariableInfo.#resolveNodeComponentId(
+                node,
+                variableInfo,
+                obj.#componentOptions
+            );
 
             if (i === 0) {
                 obj.#displayComponentId = thisComponentId;
@@ -117,6 +113,37 @@ export class AggregateVariableInfo {
         return obj;
     }
 
+    /**
+     * The node's component when it names an option of this variable and has a range, else the variable's first option.
+     *
+     * A node holds one component, belonging to the variable it is coloured by,
+     * and it is read here for every variable in its collection.  A component
+     * with a range but no option (component 0 of a one-component variable,
+     * whose only option is the magnitude) is therefore replaced too.
+     *
+     * @param node - Scene node whose configured component is read.
+     * @param variableInfo - Variable the component is resolved for.
+     * @param componentOptions - The variable's options, keyed by component ID string.
+     * @returns The component ID to display for this node.
+     */
+    static #resolveNodeComponentId(
+        node: VisorSceneNodeExtended,
+        variableInfo: VisorVariableInfo,
+        componentOptions: ReadonlyMap<string, AggregateVariableComponentInfo>
+    ): number | null {
+        const componentId: number | null = node.variableComponent;
+        const variable = node.variableCollection.getVariable(variableInfo.id);
+        const firstOptionId = (variable ?? variableInfo).componentOptions[0].id;
+
+        if (componentId == null || !componentOptions.has(componentId.toString())) {
+            return firstOptionId;
+        }
+        if (variable != null && variable.getRangeInfo(componentId) == null) {
+            return firstOptionId;
+        }
+        return componentId;
+    }
+
     /**
      * Gets the variable's unique identifier.
      *

src/ansys/visor/visor-client/src/jest-tests/AggregateVariableInfo.test.tsx

@@ -255,7 +255,7 @@ describe('AggregateVariableInfo', () => {
         expect(component.displayVariableMax).toBe(5);
     });
 
-    test('warns when a displayed component has range data but no component option', async () => {
+    test('falls back to the first option when a displayed component has range data but no component option', async () => {
         const warningSpy = jest.spyOn(console, 'warn').mockImplementation(() => {});
 
         const variable = createVariable({
@@ -280,9 +280,9 @@ describe('AggregateVariableInfo', () => {
 
         const result = selection.currentVariableInfo!;
 
-        expect(result.displayComponentId).toBe(999);
-        expect(result.currentComponentInfo).toBeUndefined();
-        expect(warningSpy).toHaveBeenCalledWith("invalid componentId: '999'");
+        expect(result.displayComponentId).toBe(-1);
+        expect(result.currentComponentInfo).toBe(result.componentOptions.get('-1'));
+        expect(warningSpy).not.toHaveBeenCalled();
     });
 
     test('setDisplayComponentId selects a component by number', async () => {

src/ansys/visor/visor-client/src/jest-tests/VariableRecordProjection.test.tsx

@@ -670,3 +670,73 @@ describe('the range trigger is sent for an edit and never for a delivery', () =>
         expect(rangeSends(triggerSender)).toEqual([]);
     });
 });
+
+/** Sets a panel `<select>` to a value and lets its change handler settle. */
+async function chooseOption(select: HTMLSelectElement, value: string): Promise<void> {
+    select.value = value;
+    await act(async () => {
+        fireEvent.change(select);
+        await new Promise((resolve) => setTimeout(resolve, 0));
+    });
+}
+
+/** The panel `<select>` holding an option with the given value. */
+function selectHolding(container: HTMLElement, value: string): HTMLSelectElement {
+    return container.querySelector(`select option[value="${value}"]`)!
+        .parentElement as HTMLSelectElement;
+}
+
+describe('re-selection carries the node component only where it names an option', () => {
+    test('a scalar is applied after re-selecting a part coloured by a vector component X', async () => {
+        const { frontend, renderer } = makeFrontend();
+        const part = frontend.sceneGraph.descendantActorNodesOrSelfDictionary[PART_A_ID];
+        frontend.setTreeViewUtil(makeTreeViewUtilDouble([part]));
+        await frontend.setAppStateAsync(
+            {
+                scene: {
+                    variableStates: {
+                        [VELOCITY_ID]: velocityRecord(),
+                        [PRESSURE_ID]: pressureRecord(),
+                    },
+                },
+            },
+            false
+        );
+        await part.setColorVariableAsync(VELOCITY_ID, -1);
+
+        let container: HTMLElement = null!;
+        await act(async () => {
+            container = render(
+                <Panel_TopRight visorState={frontend} onLoad={() => {}} />
+            ).container;
+        });
+        const util = await frontend.panelTopRightUtilPromise;
+        const warningSpy = jest.spyOn(console, 'warn').mockImplementation(() => {});
+        try {
+            await chooseOption(selectHolding(container, '0'), '0');
+            await act(async () => {
+                await util.refreshSelectionAsync();
+            });
+            renderer.sendPartColorVariableAsync.mockClear();
+
+            await chooseOption(selectHolding(container, PRESSURE_ID), PRESSURE_ID);
+
+            expect(renderer.sendPartColorVariableAsync.mock.calls).toEqual([
+                [
+                    1,
+                    {
+                        variableId: 'POINT::pressure::1',
+                        variableType: 'POINT',
+                        variableName: 'pressure',
+                        component: -1,
+                        min: 2,
+                        max: 8,
+                    },
+                ],
+            ]);
+            expect(warningSpy).not.toHaveBeenCalledWith("invalid componentId: '0'");
+        } finally {
+            warningSpy.mockRestore();
+        }
+    });
+});