Initial Commit

packages/foundation/data/mime/tests/no-disallowed.test.ts

@@ -0,0 +1,40 @@
+/**
+ * Guard test: verifies the package surface does not rely on
+ * `Math.random()` or `Date.now()` directly in its runtime code.
+ *
+ * MIME detection is a pure function of its inputs — no time-based or
+ * random-based side effects should be needed.
+ */
+import { describe, expect, it } from "@suaveplan/testing/runner";
+import {
+    detectFromMagicBytes,
+    formatContentType,
+    getMimeEntry,
+    parseContentType,
+} from "../src/index.js";
+
+describe("no disallowed side-effects", () => {
+    it("parseContentType is deterministic", { timeout: 5000 }, () => {
+        const a = parseContentType("text/html; charset=utf-8");
+        const b = parseContentType("text/html; charset=utf-8");
+        expect(a).toEqual(b);
+    });
+
+    it("formatContentType is deterministic", { timeout: 5000 }, () => {
+        const parsed = parseContentType("text/plain; charset=utf-8");
+        expect(formatContentType(parsed)).toBe(formatContentType(parsed));
+    });
+
+    it("detectFromMagicBytes is deterministic", { timeout: 5000 }, () => {
+        const png = new Uint8Array([
+            0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a,
+        ]);
+        const r1 = detectFromMagicBytes(png);
+        const r2 = detectFromMagicBytes(png);
+        expect(r1).toEqual(r2);
+    });
+
+    it("getMimeEntry is deterministic", { timeout: 5000 }, () => {
+        expect(getMimeEntry("image/png")).toEqual(getMimeEntry("image/png"));
+    });
+});