[Init] Initial commit - NetMesh terminal manager

application/state/themeTransition.test.ts

@@ -0,0 +1,129 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import {
+  THEME_TRANSITION_ATTR,
+  THEME_TRANSITION_MS,
+  runThemeTransition,
+} from "./themeTransition.ts";
+
+function createRoot() {
+  const attributes = new Map<string, string>();
+  return {
+    attributes,
+    ownerDocument: { startViewTransition: undefined },
+    setAttribute: (name: string, value: string) => attributes.set(name, value),
+    removeAttribute: (name: string) => attributes.delete(name),
+    getAttribute: (name: string) => attributes.get(name) ?? null,
+  } as unknown as HTMLElement;
+}
+
+test("runThemeTransition applies tokens and clears fallback marker after duration", async () => {
+  const root = createRoot();
+  let applied = false;
+
+  runThemeTransition(() => {
+    applied = true;
+  }, root);
+
+  assert.equal(applied, true);
+  assert.equal(root.getAttribute(THEME_TRANSITION_ATTR), "true");
+
+  await new Promise((resolve) => setTimeout(resolve, THEME_TRANSITION_MS + 60));
+  assert.equal(root.getAttribute(THEME_TRANSITION_ATTR), null);
+});
+
+test("runThemeTransition cancels a pending fallback reset when invoked again", () => {
+  const root = createRoot();
+  let count = 0;
+
+  runThemeTransition(() => {
+    count += 1;
+  }, root);
+  runThemeTransition(() => {
+    count += 2;
+  }, root);
+
+  assert.equal(count, 3);
+  assert.equal(root.getAttribute(THEME_TRANSITION_ATTR), "true");
+});
+
+test("runThemeTransition uses view transition API when available", async () => {
+  const root = createRoot();
+  let applied = false;
+  let finished = false;
+  const doc = {
+    startViewTransition: (callback: () => void) => {
+      callback();
+      return {
+        finished: Promise.resolve().then(() => {
+          finished = true;
+        }),
+        skipTransition: () => {},
+      };
+    },
+  };
+  (root as { ownerDocument: typeof doc }).ownerDocument = doc;
+
+  runThemeTransition(() => {
+    applied = true;
+  }, root);
+
+  assert.equal(applied, true);
+  assert.equal(root.getAttribute(THEME_TRANSITION_ATTR), null);
+  await new Promise((resolve) => setTimeout(resolve, 0));
+  assert.equal(finished, true);
+});
+
+test("runThemeTransition handles skipped view transitions", async () => {
+  const root = createRoot();
+  let applied = false;
+  let rejectFinished!: (reason: unknown) => void;
+  const doc = {
+    startViewTransition: (callback: () => void) => {
+      callback();
+      return {
+        finished: new Promise<void>((_, reject) => {
+          rejectFinished = reject;
+        }),
+        skipTransition: () => {},
+      };
+    },
+  };
+  (root as { ownerDocument: typeof doc }).ownerDocument = doc;
+
+  runThemeTransition(() => {
+    applied = true;
+  }, root);
+
+  rejectFinished(new DOMException("Transition was skipped", "AbortError"));
+  await new Promise((resolve) => setTimeout(resolve, 0));
+
+  assert.equal(applied, true);
+  assert.equal(root.getAttribute(THEME_TRANSITION_ATTR), null);
+});
+
+test("runThemeTransition can apply without animation for heavy tab switches", () => {
+  const root = createRoot();
+  let applied = false;
+  let startViewTransitionCalled = false;
+  const doc = {
+    startViewTransition: (callback: () => void) => {
+      startViewTransitionCalled = true;
+      callback();
+      return {
+        finished: Promise.resolve(),
+        skipTransition: () => {},
+      };
+    },
+  };
+  (root as { ownerDocument: typeof doc }).ownerDocument = doc;
+
+  runThemeTransition(() => {
+    applied = true;
+  }, { root, mode: "instant" });
+
+  assert.equal(applied, true);
+  assert.equal(startViewTransitionCalled, false);
+  assert.equal(root.getAttribute(THEME_TRANSITION_ATTR), null);
+});