test(street-level): harden KartaView tests (mutation score 51% → 95%)

A mutation review (91, then 130 mutants) found tests that could not fail
(quick presses with synchronous fakes, a no-flight check with a provider
that never posed), and untested paths. New and rewritten tests kill 123 of
130 mutants; the 7 survivors are equivalent or harmless redraws.

- viewer: held-back loads for quick presses, stale sharp/flat loads,
  close mid-load, ends checks for an older photo, WebGL retried per mount,
  focus handed back, look direction kept on ›.
- provider: id-ordered pages with out-of-order indexes, page and probe
  failures retried, overtaken lookups, cones re-centred on ‹ ›, leftover
  imagery filters hide no line or cone, coverage hints, tile cache.
- source: 429 backoff and Retry-After under mock timers, hang timeouts,
  the nearest query's parameters. policy: storage-host injection, FOV 360,
  longitudes past ±180. panorama: a stub WebGL context (angles, lost
  context, re-measuring). lineCoverage.test.mjs: tooHigh hint, passes().
- core: openImage({frame:false}) and openNearest leave the camera
  (with a posing provider and a default-open control), KartaView's legend
  and wording end to end; viewerHost supportsRenderModes.
- Fixed tick-count waits replaced by an until() poll.
- Browser gate fixture: odd photos archived (409 at storage2, served by
  the proxy), the first lookup rate-limited (429, Retry-After: 0); the
  line-click step asserts the camera stays and › skips the archived photo.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

scripts/fixtures/street-level/kartaView.mjs

@@ -6,7 +6,11 @@ import { metresApart, photoJpeg } from './mapillaryGraph.mjs';
  * the gate's KartaView steps need no network. One drive runs north along
  * KV_LINE; every tenth photo is a 360° one. Photos live on storage2 while
  * their `fileurl*` name storage1, as KartaView's API does, so the gate also
- * proves the provider builds addresses from `storage`.
+ * proves the provider builds addresses from `storage`. Every odd-indexed
+ * photo is archived (storage answers 409, the image proxy still serves it),
+ * so the nearest photo opened is even and › must skip the one after it. The
+ * first nearest-photo lookup is rate-limited (429, Retry-After: 0), as
+ * KartaView does under load.
  */
 
 export const KV_SEQUENCE_ID = '900001';
@@ -21,7 +25,15 @@ const SHOT = '2024-05-02 16:20:00.000';
 
 const CORS = Object.freeze({ 'Access-Control-Allow-Origin': '*' });
 
-/** The drive's photos, south to north; every tenth is 360°. */
+/** Lookups answered so far: the first one is rate-limited. */
+let nearestLookups = 0;
+
+/** Forget the lookups answered, so the next one is rate-limited again. */
+export function resetKartaViewFixture() {
+  nearestLookups = 0;
+}
+
+/** The drive's photos, south to north; every tenth is 360°, every odd one archived. */
 export function kartaViewPhotos() {
   const step = KV_SPACING_M / METRES_PER_DEG_LAT;
   const count = Math.floor((KV_LINE.north - KV_LINE.south) / step) + 1;
@@ -31,6 +43,7 @@ export function kartaViewPhotos() {
     lon: KV_LINE.lon,
     lat: Number((KV_LINE.south + i * step).toFixed(7)),
     isPano: i % 10 === 5,
+    archived: i % 2 === 1,
   }));
 }
 
@@ -127,10 +140,16 @@ export function answerKartaViewRequest({ method, url }) {
     return /^\/pr:sharp\/rs:fit:\d+:\d+\/[\w-]+$/.test(address.pathname)
       ? image
       : { ...raw(404, {}), known: false };
-  if (address.hostname === 'storage2.openstreetcam.org')
-    return address.pathname.includes(KV_SEQUENCE_ID)
-      ? image
-      : { ...raw(404, {}), known: false };
+  if (address.hostname === 'storage2.openstreetcam.org') {
+    if (!address.pathname.includes(KV_SEQUENCE_ID))
+      return { ...raw(404, {}), known: false };
+    const archived = photos.some(
+      (photo) =>
+        photo.archived && address.pathname.endsWith(`_${photo.id}.jpg`),
+    );
+    // An archived photo's file is gone from storage: KartaView answers 409.
+    return archived ? { ...raw(409, {}), known: true } : image;
+  }
   if (/^storage\d+\.openstreetcam\.org$/.test(address.hostname))
     // The wrong host the API names: KartaView answers 404 there.
     return { ...raw(404, {}), known: false };
@@ -148,6 +167,16 @@ export function answerKartaViewRequest({ method, url }) {
       known: true,
     };
   if (path === '/2.0/photo/') {
+    if (nearestLookups++ === 0)
+      return {
+        ...raw(429, {}),
+        headers: {
+          ...CORS,
+          'Retry-After': '0',
+          'Access-Control-Expose-Headers': 'Retry-After',
+        },
+        known: true,
+      };
     const q = address.searchParams;
     const at = { lat: Number(q.get('lat')), lon: Number(q.get('lng')) };
     const near = photos

scripts/format-scope.json

@@ -921,6 +921,7 @@
   "src/layers/streetLevel/providers/kartaview/panorama.test.mjs",
   "src/layers/streetLevel/providers/kartaview/viewer.test.mjs",
   "src/layers/streetLevel/providers/kartaview/provider.test.mjs",
+  "src/layers/streetLevel/lineCoverage.test.mjs",
   "src/testSupport/kartaViewFakes.mjs",
   "src/testSupport/googleStreetViewFakes.mjs",
   "server/providers/mapillary.js",

scripts/qa-street-level.mjs

@@ -850,7 +850,7 @@ async function main() {
         },
       );
       await step(
-        'KartaView: a click on a line opens the nearest photo, cones follow its drive, and › steps along it',
+        'KartaView: a click on a line opens the nearest photo where the camera is, cones follow its drive, and › steps along it, past an archived photo',
         async ({ skip }) => {
           const along = Array.from({ length: 9 }, (_, i) => [
             KV_LINE.lon,
@@ -871,6 +871,17 @@ async function main() {
           if (!handle && !fixtures) return skip('no KartaView line in view');
           assert.ok(handle, 'a KartaView line is pickable');
           const at = await handle.jsonValue();
+          const camera = () =>
+            page.evaluate(() => {
+              const c = window.__godsEyeView.viewer.camera.positionCartographic;
+              return {
+                lon: (c.longitude * 180) / Math.PI,
+                lat: (c.latitude * 180) / Math.PI,
+                height: c.height,
+              };
+            });
+          const parked = await camera();
+          // The first lookup is rate-limited (fixtures): it waits and retries.
           await page.mouse.click(at.x, at.y);
           await page.waitForFunction(
             () => {
@@ -894,10 +905,22 @@ async function main() {
             }),
             'the photo is on screen',
           );
+          // A line click picks a spot: the camera stays where it was.
+          await sleep(1500);
+          const now = await camera();
+          assert.ok(
+            Math.abs(now.lon - parked.lon) < 1e-6 &&
+              Math.abs(now.lat - parked.lat) < 1e-6 &&
+              Math.abs(now.height - parked.height) < 0.5,
+            `the camera did not move: ${JSON.stringify({ parked, now })}`,
+          );
           if (fixtures) {
-            assert.ok(
-              photos.some((photo) => photo.id === street.imageId),
-              `${street.imageId} is a fixture photo`,
+            const opened = photos.find((photo) => photo.id === street.imageId);
+            assert.ok(opened, `${street.imageId} is a fixture photo`);
+            assert.equal(
+              opened.archived,
+              false,
+              'the nearest photo that storage still has',
             );
             assert.ok(
               await uiUntil(
@@ -922,12 +945,21 @@ async function main() {
             ),
             '› opened the next photo',
           );
-          if (fixtures)
+          if (fixtures) {
+            const skipped = photos.find(
+              (photo) => photo.id === String(Number(before) + 1),
+            );
+            assert.equal(
+              skipped?.archived,
+              true,
+              'the photo after is archived',
+            );
             assert.equal(
               (await ui()).street.imageId,
-              String(Number(before) + 1),
-              'the next photo along the drive',
+              String(Number(before) + 2),
+              '› skipped the archived photo to the next one along the drive',
             );
+          }
         },
       );
       if (fixtures)