1 files changed, 40 insertions, 0 deletions
diff --git a/src/components/rich-text/node-format.test.ts b/src/components/rich-text/node-format.test.ts
new file mode 100644
index 0000000..476a0d9
--- /dev/null
+++ b/src/components/rich-text/node-format.test.ts
@@ -0,0 +1,40 @@
+import { describe, expect, test } from 'vitest';
+import {
+  IS_BOLD,
+  IS_CODE,
+  IS_HIGHLIGHT,
+  IS_ITALIC,
+  IS_STRIKETHROUGH,
+  IS_SUBSCRIPT,
+  IS_SUPERSCRIPT,
+  IS_UNDERLINE,
+} from './node-format';
+
+describe('node format bit flags', () => {
+  test('uses power-of-two values for unique bitmasks', () => {
+    const flags = [
+      IS_BOLD,
+      IS_ITALIC,
+      IS_STRIKETHROUGH,
+      IS_UNDERLINE,
+      IS_CODE,
+      IS_SUBSCRIPT,
+      IS_SUPERSCRIPT,
+      IS_HIGHLIGHT,
+    ];
+
+    for (const flag of flags) {
+      expect((flag & (flag - 1)) === 0).toBe(true);
+    }
+  });
+
+  test('can combine and detect individual flags with bitwise operations', () => {
+    const format = IS_BOLD | IS_ITALIC | IS_CODE;
+
+    expect((format & IS_BOLD) !== 0).toBe(true);
+    expect((format & IS_ITALIC) !== 0).toBe(true);
+    expect((format & IS_CODE) !== 0).toBe(true);
+    expect((format & IS_UNDERLINE) !== 0).toBe(false);
+  });
+});
+