test(auth): add unit tests for ltProxyAuth and ltProxyHandler

- Add tests to validate ltProxyAuth behavior for valid, invalid, and missing API keys
- Add tests to verify ltProxyHandler correctly proxies requests and returns responses

src/__tests__/ltProxyAuth.test.ts

@@ -0,0 +1,63 @@
+// deno-lint-ignore-file require-await
+import { assertEquals } from 'https://deno.land/std@0.204.0/assert/mod.ts';
+import type { IContext } from 'http-kernel/Interfaces/mod.ts';
+import { ltProxyAuth } from '../ltProxyAuth.ts';
+
+Deno.test('ltProxyAuth: accepts valid API key', async () => {
+    Deno.env.set('API_KEYS', 'valid123');
+
+    const req = new Request('http://localhost/?apiKey=valid123');
+    const ctx: IContext = {
+        req,
+        params: {},
+        query: { apiKey: 'valid123' },
+        state: {},
+    };
+
+    const response = await ltProxyAuth(
+        ctx,
+        async () => new Response('OK', { status: 200 }),
+    );
+
+    assertEquals(response.status, 200);
+    assertEquals(await response.text(), 'OK');
+});
+
+Deno.test('ltProxyAuth: rejects invalid API key', async () => {
+    Deno.env.set('API_KEYS', 'valid123');
+
+    const req = new Request('http://localhost/?apiKey=invalid456');
+    const ctx: IContext = {
+        req,
+        params: {},
+        query: { apiKey: 'invalid456' },
+        state: {},
+    };
+
+    const response = await ltProxyAuth(
+        ctx,
+        async () => new Response('SHOULD NOT HAPPEN'),
+    );
+
+    assertEquals(response.status, 403);
+    assertEquals(await response.text(), 'Forbidden – Invalid API key');
+});
+
+Deno.test('ltProxyAuth: rejects missing API key', async () => {
+    Deno.env.set('API_KEYS', 'valid123');
+
+    const req = new Request('http://localhost/');
+    const ctx: IContext = {
+        req,
+        params: {},
+        query: {},
+        state: {},
+    };
+
+    const response = await ltProxyAuth(
+        ctx,
+        async () => new Response('SHOULD NOT HAPPEN'),
+    );
+
+    assertEquals(response.status, 403);
+});

src/__tests__/ltProxyHandler.test.ts

@@ -0,0 +1,44 @@
+// deno-lint-ignore-file require-await
+import { ltProxyHandler } from '../ltProxyHandler.ts';
+import { assertEquals } from 'https://deno.land/std@0.204.0/assert/mod.ts';
+import type { IContext } from 'http-kernel/Interfaces/mod.ts';
+
+Deno.test('ltProxyHandler: proxies request and returns response', async () => {
+    const expectedResponse = new Response('Mocked LT Response', {
+        status: 200,
+        headers: {
+            'content-type': 'text/plain',
+            'x-mocked': 'true',
+        },
+    });
+
+    // Backup and mock global fetch
+    const originalFetch = globalThis.fetch;
+    globalThis.fetch = async () => expectedResponse;
+
+    const req = new Request('http://localhost/v2/check?language=de-DE', {
+        method: 'POST',
+        body: new TextEncoder().encode('text=Hallo+Welt'),
+        headers: {
+            'content-type': 'application/x-www-form-urlencoded',
+        },
+    });
+
+    const ctx: IContext = {
+        req,
+        params: {},
+        query: {
+            language: 'de-DE',
+        },
+        state: {},
+    };
+
+    const response = await ltProxyHandler(ctx);
+
+    assertEquals(response.status, 200);
+    assertEquals(await response.text(), 'Mocked LT Response');
+    assertEquals(response.headers.get('x-mocked'), 'true');
+
+    // Restore fetch
+    globalThis.fetch = originalFetch;
+});