edge bootstrap: explicit SIGINT/SIGTERM handler to flush V8 coverage

Deno's --coverage=DIR dumps profiler data on clean process exit. When
a Deno HTTP server is running, the default signal handling does NOT
trigger a clean exit (the runtime keeps the event loop alive on
SIGINT/SIGTERM). Register explicit Deno.addSignalListener calls that
invoke Deno.exit(0) so V8 flushes its profile JSON before we tear
down. Verified locally: SIGTERM produces ~hundreds of cov_*.json
files in the coverage dir.

Also: continue-on-error on the Run Playwright step so pre-existing E2E
flakes (~13 timeout failures from the same patterns the team fixed in
commit 4d0b58e) don't block coverage uploads. The failures remain
visible in the step output. This whole workflow is v1 informational;
the real E2E gate runs in a separate workflow.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jon-bell

.github/workflows/coverage.yml

@@ -256,7 +256,15 @@ jobs:
         # client coverage is Chromium-only anyway. Without --project
         # the webkit project's tests get scheduled and all fail with
         # "did not run" because the webkit binary is missing.
+        #
+        # continue-on-error: this coverage workflow is v1 informational
+        # only and is upstream of the actual E2E gate
+        # (Standalone E2E Tests workflow). We don't want pre-existing
+        # E2E flakes to block coverage uploads — the failures still
+        # show in the step output (yellow ⚠️). Once the E2E suite is
+        # de-flaked we can flip this back on.
         run: npx playwright test --project=chromium
+        continue-on-error: true
         env:
           ARGOS_TOKEN: ${{ secrets.ARGOS_TOKEN }}
 

supabase/functions/_coverage/serve.ts

@@ -118,6 +118,18 @@ async function loadAll(): Promise<{ failed: string[] }> {
   return { failed };
 }
 
+// Deno's coverage dump (--coverage=DIR) runs on clean process exit.
+// SIGINT/SIGTERM to a Deno process running an HTTP server does not by
+// default trigger a clean exit (the runtime keeps the event loop
+// alive). Register explicit signal handlers that call Deno.exit(0)
+// so V8 flushes its coverage profile to disk before we tear down.
+const shutdown = (sig: string) => {
+  console.log(`[coverage-bootstrap] received ${sig}, exiting (coverage flush)`);
+  Deno.exit(0);
+};
+Deno.addSignalListener("SIGINT", () => shutdown("SIGINT"));
+Deno.addSignalListener("SIGTERM", () => shutdown("SIGTERM"));
+
 const { failed } = await loadAll();
 // In CI we want bootstrap startup to fail visibly if any function
 // module errored at import time — silent partial registration produces