fix(runner): rebuild PR-pinned demos when the PR gets a new commit (DEV-3338)

runner/pipeline/demo-routes-version.test.mjs

@@ -53,6 +53,10 @@ globalThis.fetch = async (input, init) => {
   if (url.startsWith("https://login.invalid") && init?.headers?.Authorization === "Bearer test-token") {
     return Response.json({ email: AUTHOR, sub: "u1" });
   }
+  // A PR build looks up the PR's current commit (DEV-3338).
+  if (url.startsWith("https://pkg.pr.new/") && init?.method === "HEAD") {
+    return new Response(null, { headers: { "x-commit-key": "handsontable:handsontable:abc1234" } });
+  }
   // Anything else is a test escaping its sandbox. A throw inside
   // authenticate's try/catch reads as 401, inside fetchVersionCatalog as 502 —
   // both fail the asserting test loudly instead of reaching a live registry.

runner/pipeline/fixtures/worker-harness.mjs

@@ -49,6 +49,9 @@ export function parseDemosInsert(sql, binds) {
  */
 export function fakeD1(seedRows = [], seedTokens = [], { buildCacheHit = true } = {}) {
   const writes = [];
+  // The build_cache keys asked for, in order — the only observable of what a
+  // build is keyed on, since the fake answers every lookup alike.
+  const cacheLookups = [];
   const demos = new Map(seedRows.map((row) => [row.id, row]));
   const tokens = new Map(seedTokens.map((row) => [row.id, { ...row }]));
   const prepare = (sql) => {
@@ -60,8 +63,13 @@ export function fakeD1(seedRows = [], seedTokens = [], { buildCacheHit = true }
           // and so a route that forgets to write a change cannot appear to.
           return row ? { ...row } : null;
         }
-        if (/FROM demos WHERE id = \?/.test(sql)) return demos.get(binds[0]) ?? null;
+        if (/FROM demos WHERE id = \?/.test(sql)) {
+          // A copy, as D1 returns: a caller holding a row must not see later writes.
+          const row = demos.get(binds[0]);
+          return row ? { ...row } : null;
+        }
         if (/FROM build_cache/.test(sql)) {
+          cacheLookups.push(binds[0]);
           return buildCacheHit ? { r2_prefix: "demos/_prior-identical-build/" } : null;
         }
         return null;
@@ -71,7 +79,7 @@ export function fakeD1(seedRows = [], seedTokens = [], { buildCacheHit = true }
         const inserted = parseDemosInsert(sql, binds);
         if (inserted) demos.set(inserted.id, inserted);
         applyTokenWrite(tokens, sql, binds);
-        return { success: true, meta: {} };
+        return { success: true, meta: { changes: applyPrRefreshWrite(demos, sql, binds) } };
       },
       async all() {
         if (/FROM api_tokens ORDER BY created_at DESC/.test(sql)) {
@@ -85,7 +93,36 @@ export function fakeD1(seedRows = [], seedTokens = [], { buildCacheHit = true }
     });
     return { bind: (...binds) => bound(binds), ...bound([]) };
   };
-  return { db: { prepare }, writes, demos, tokens };
+  return { db: { prepare }, writes, demos, tokens, cacheLookups };
+}
+
+/**
+ * Apply the PR-refresh claim (pr-refresh.ts) and its undo to the `demos` map,
+ * honouring the claim's WHERE clause and answering `meta.changes` — the claim is
+ * only atomic because of that condition, so a fake that always applied it would
+ * pass a double-scheduling bug.
+ */
+function applyPrRefreshWrite(demos, sql, binds) {
+  if (/UPDATE demos SET build_status='building', build_error=NULL, ht_attempt_sha=\?/.test(sql)) {
+    // Each condition applies only while the SQL still says it.
+    const [sha, now, id, staleBefore, notSha, version] = binds;
+    const row = demos.get(id);
+    const staleClause = /build_status!='building' OR updated_at<\?/.test(sql);
+    const busy = row?.build_status === "building" && !(staleClause && row.updated_at < staleBefore);
+    const retry = /COALESCE\(ht_attempt_sha,''\)!=\?/.test(sql) && (row?.ht_attempt_sha ?? "") === notSha;
+    const moved = /AND ht_version=\?/.test(sql) && row?.ht_version !== version;
+    if (!row || busy || retry || moved) return 0;
+    Object.assign(row, { build_status: "building", build_error: null, ht_attempt_sha: sha, updated_at: now });
+    return 1;
+  }
+  if (/UPDATE demos SET build_status=\?, ht_attempt_sha=\?, updated_at=\? WHERE id=\?/.test(sql)) {
+    const [status, sha, updatedAt, id] = binds;
+    const row = demos.get(id);
+    if (!row) return 0;
+    Object.assign(row, { build_status: status, ht_attempt_sha: sha, updated_at: updatedAt });
+    return 1;
+  }
+  return undefined;
 }
 
 /**
@@ -238,7 +275,7 @@ export const AUTHOR = "dev@handsontable.com";
  * under test on the browser routes.
  */
 export function makeEnv(seedRows = [], seedTokens = [], seedArtifacts = {}, opts = {}) {
-  const { db, writes, demos, tokens } = fakeD1(seedRows, seedTokens, opts);
+  const { db, writes, demos, tokens, cacheLookups } = fakeD1(seedRows, seedTokens, opts);
   const artifacts = fakeR2(seedArtifacts);
   const buildJobs = fakeBuildJobs();
   const env = {
@@ -256,7 +293,7 @@ export function makeEnv(seedRows = [], seedTokens = [], seedArtifacts = {}, opts
     // Not the production host, so the Sentry gate in index.ts stays inert.
     PREVIEW_HOST: "localhost:8787",
   };
-  return { env, writes, demos, artifacts, tokens, scheduled: buildJobs.scheduled };
+  return { env, writes, demos, artifacts, tokens, cacheLookups, scheduled: buildJobs.scheduled };
 }
 
 export const ctx = {

runner/pipeline/mcp-routes.test.mjs

@@ -250,7 +250,17 @@ test("an MCP rebuild derives the bare ref from a pkg.pr.new-pinned payload and r
   // package.json asks for (bare ref in D1, exact URL in the snapshot), and the
   // sentinel is repaired rather than re-stored.
   const { env, writes, artifacts } = makeEnv([demoRow({ ht_version: "latest" })]);
-  const res = await worker.fetch(patchRequest("abc123", { files: filesWith(PR_URL) }), env, ctx);
+  // The build looks up the PR's current commit (DEV-3338); answer it here, not over the network.
+  const realFetch = globalThis.fetch;
+  globalThis.fetch = async (url, init) => String(url).startsWith("https://pkg.pr.new/")
+    ? new Response(null, { headers: { "x-commit-key": "handsontable:handsontable:abc1234" } })
+    : realFetch(url, init);
+  let res;
+  try {
+    res = await worker.fetch(patchRequest("abc123", { files: filesWith(PR_URL) }), env, ctx);
+  } finally {
+    globalThis.fetch = realFetch;
+  }
   assert.equal(res.status, 200);
   const body = await res.json();
   assert.equal(body.rebuilt, true);