test(e2e): assert ultrasound spacing via ruler tool

The Data panel only renders Spacing for non-DICOM images
(ImageDataBrowser filters via isRegularImage), so a US DICOM
never produces a "Spacing: (...)" caption — earlier attempts
to assert against that surface failed on a clean CI run.

Drop a ruler at a known canvas-pixel offset and read the
measurement from the Annotations panel. With the spacing fix
the ruler reports ~49 mm at the shared 1200×800 viewport;
without the fix the 1 mm/px fallback would yield ~97 mm. A
wide ±8 mm tolerance absorbs runner-to-runner canvas jitter
while still excluding the fallback.

Author: PaulHax

tests/specs/ultrasound-spacing.e2e.ts

@@ -2,51 +2,37 @@ import { US_MULTIFRAME_DICOM } from './configTestUtils';
 import { openUrls } from './utils';
 import { volViewPage } from '../pageobjects/volview.page';
 
-const clickAt = async (x: number, y: number) => {
-  await browser
-    .action('pointer')
-    .move({ x: Math.round(x), y: Math.round(y) })
-    .down()
-    .up()
-    .perform();
-};
-
-// Offset between the two ruler clicks (in canvas pixels).
-// The measured ruler length in mm depends on this offset, the canvas size,
-// and the image spacing. With the US spacing fix the VTK spacing comes from
-// SequenceOfUltrasoundRegions (~0.5105 mm); without the fix it falls back to
-// 1.0 mm, which makes the measured length ~1.96x larger.
-const CLICK_DX = 0;
+// Vertical ruler in canvas pixels. The reported length in mm depends on
+// canvas size, image-fit zoom, and the applied spacing. With the fix the
+// VTK spacing comes from SequenceOfUltrasoundRegions (~0.5105 mm/image-px);
+// without the fix it falls back to 1 mm/image-px and the ruler reports
+// roughly 1.96× the with-fix value.
 const CLICK_DY = 100;
 
-// Calibrated length (mm) that the ruler reports when the US spacing fix is
-// active. Obtained by running this test once with the fix enabled.
-// Without the fix the VTK spacing falls back to 1.0 mm/pixel, which makes
-// the measured length grow to ~97 mm (~1.96x) and this assertion fails.
-const EXPECTED_LENGTH_MM = 49.35;
-const LENGTH_TOLERANCE_MM = 1.5;
+// At the shared viewport (1200×800), with the fix active the ruler reports
+// about 49 mm. Without the fix the same ruler reports about 97 mm. A wide
+// tolerance lets the assertion absorb minor canvas-size jitter between
+// runners while still excluding the 1 mm fallback.
+const EXPECTED_LENGTH_MM = 49;
+const LENGTH_TOLERANCE_MM = 8;
 
 describe('Ultrasound image spacing', () => {
   it('ruler length reflects physical spacing from SequenceOfUltrasoundRegions', async () => {
     await openUrls([US_MULTIFRAME_DICOM]);
+    await volViewPage.waitForViews();
 
-    // Activate the ruler tool
     const rulerBtn = await $('button span i[class~=mdi-ruler]');
     await rulerBtn.waitForClickable();
     await rulerBtn.click();
 
-    // Place the ruler on the first view's canvas
+    // element.click({ x, y }) offsets are measured from the element's center,
+    // so x:0 / y:0 is the canvas center.
     const views = await volViewPage.views;
     const canvas = views[0];
-    const loc = await canvas.getLocation();
-    const size = await canvas.getSize();
-    const cx = loc.x + size.width / 2;
-    const cy = loc.y + size.height / 2;
 
-    await clickAt(cx - CLICK_DX / 2, cy - CLICK_DY / 2);
-    await clickAt(cx + CLICK_DX / 2, cy + CLICK_DY / 2);
+    await canvas.click({ x: 0, y: -CLICK_DY / 2 });
+    await canvas.click({ x: 0, y: CLICK_DY / 2 });
 
-    // Open Annotations > Measurements to read the ruler length
     const annotationsTab = await $(
       'button[data-testid="module-tab-Annotations"]'
     );
@@ -56,7 +42,6 @@ describe('Ultrasound image spacing', () => {
     await measurementsTab.waitForClickable();
     await measurementsTab.click();
 
-    // The ruler details panel renders `{value}mm`; read the first length.
     let lengthMm = 0;
     await browser.waitUntil(
       async () => {
@@ -79,14 +64,7 @@ describe('Ultrasound image spacing', () => {
 
     console.log(`[ultrasound-spacing] measured ruler length: ${lengthMm} mm`);
 
-    if (EXPECTED_LENGTH_MM > 0) {
-      expect(lengthMm).toBeGreaterThan(
-        EXPECTED_LENGTH_MM - LENGTH_TOLERANCE_MM
-      );
-      expect(lengthMm).toBeLessThan(EXPECTED_LENGTH_MM + LENGTH_TOLERANCE_MM);
-    } else {
-      // Calibration mode: any positive value passes, actual number is logged.
-      expect(lengthMm).toBeGreaterThan(0);
-    }
+    expect(lengthMm).toBeGreaterThan(EXPECTED_LENGTH_MM - LENGTH_TOLERANCE_MM);
+    expect(lengthMm).toBeLessThan(EXPECTED_LENGTH_MM + LENGTH_TOLERANCE_MM);
   });
 });