From e999f2aae3e7f4952634e4b72acefd07d2d3e57a Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Sat, 28 Mar 2026 13:13:02 +0000
Subject: [PATCH] test: silence lit dev-mode warnings in ui suite

---
 ui/src/test-helpers/lit-warnings.setup.ts | 6 ++++++
 ui/vitest.config.ts                       | 3 +++
 2 files changed, 9 insertions(+)
 create mode 100644 ui/src/test-helpers/lit-warnings.setup.ts

diff --git a/ui/src/test-helpers/lit-warnings.setup.ts b/ui/src/test-helpers/lit-warnings.setup.ts
new file mode 100644
index 00000000000..6680350ef04
--- /dev/null
+++ b/ui/src/test-helpers/lit-warnings.setup.ts
@@ -0,0 +1,6 @@
+// Lit emits a one-time dev-mode warning in test builds. Pre-mark it as issued
+// so broad UI suites stay signal-heavy instead of repeating the same console.warn.
+const issuedWarnings = ((globalThis as { litIssuedWarnings?: Set<string> }).litIssuedWarnings ??=
+  new Set<string>());
+
+issuedWarnings.add("dev-mode");
diff --git a/ui/vitest.config.ts b/ui/vitest.config.ts
index 220967cfd1e..501f532fa3e 100644
--- a/ui/vitest.config.ts
+++ b/ui/vitest.config.ts
@@ -10,6 +10,7 @@ export default defineConfig({
           include: ["src/**/*.test.ts"],
           exclude: ["src/**/*.browser.test.ts", "src/**/*.node.test.ts"],
           environment: "jsdom",
+          setupFiles: ["./src/test-helpers/lit-warnings.setup.ts"],
         },
       }),
       defineProject({
@@ -17,12 +18,14 @@ export default defineConfig({
           name: "unit-node",
           include: ["src/**/*.node.test.ts"],
           environment: "jsdom",
+          setupFiles: ["./src/test-helpers/lit-warnings.setup.ts"],
         },
       }),
       defineProject({
         test: {
           name: "browser",
           include: ["src/**/*.browser.test.ts"],
+          setupFiles: ["./src/test-helpers/lit-warnings.setup.ts"],
           browser: {
             enabled: true,
             provider: playwright(),