test(llm): add unit tests for tokenReferenceRule functionality

- Introduced tests for the tokenReferenceRule to validate its behavior in converting TokenReference components to markdown tables.
- Added scenarios for handling groups, including cases with known and unknown groups to ensure robustness of the normalization process.

Author: SeieunYoo

docs/app/_llms/rules/token-reference-rule.test.ts

@@ -0,0 +1,34 @@
+import { describe, expect, it } from "bun:test";
+import { normalizeLLMBodyWithRules } from "../normalize-llm-body";
+import { tokenReferenceRule } from "./token-reference-rule";
+
+describe("tokenReferenceRule", () => {
+  it("converts TokenReference with groups to a markdown table", () => {
+    const input = `<TokenReference groups={["radius"]} />`;
+
+    const actual = normalizeLLMBodyWithRules(input, [tokenReferenceRule]);
+
+    expect(actual).toContain("| Token |");
+    expect(actual).toContain("| --- |");
+    expect(actual).toContain("$radius.");
+  });
+
+  it("converts TokenReference without groups to all token tables with headings", () => {
+    const input = "<TokenReference />";
+
+    const actual = normalizeLLMBodyWithRules(input, [tokenReferenceRule]);
+
+    expect(actual).toContain("## ");
+    expect(actual).toContain("| Token |");
+    expect(actual).toContain("$radius.");
+    expect(actual).toContain("$color.");
+  });
+
+  it("keeps the original node when group is unknown", () => {
+    const input = `<TokenReference groups={["nonexistent"]} />`;
+
+    const actual = normalizeLLMBodyWithRules(input, [tokenReferenceRule]);
+
+    expect(actual).toContain("TokenReference");
+  });
+});