feat: add refresh retry/timeout and tests

tests/refresh-client.test.js

@@ -0,0 +1,112 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { requestRefreshToken } from '../refresh-client.js';
+
+function mockResponse({ ok, status, jsonData, textData, headers }) {
+  const normalizedHeaders = {};
+  if (headers) {
+    for (const [key, value] of Object.entries(headers)) {
+      normalizedHeaders[key.toLowerCase()] = value;
+    }
+  }
+
+  return {
+    ok,
+    status,
+    json: async () => jsonData ?? {},
+    text: async () => textData ?? '',
+    headers: {
+      get: (name) => normalizedHeaders[name.toLowerCase()] ?? null
+    }
+  };
+}
+
+test('refresh retries on 500 then succeeds', async () => {
+  let calls = 0;
+  const fetchImpl = async () => {
+    calls += 1;
+    if (calls === 1) {
+      return mockResponse({ ok: false, status: 500, textData: 'boom' });
+    }
+    return mockResponse({
+      ok: true,
+      status: 200,
+      jsonData: { access_token: 'access', refresh_token: 'refresh' }
+    });
+  };
+
+  const data = await requestRefreshToken({
+    refreshUrl: 'https://example.com',
+    refreshToken: 'refresh_token',
+    clientId: 'client',
+    timeoutMs: 20,
+    maxRetries: 1,
+    retryDelayMs: 1,
+    fetchImpl
+  });
+
+  assert.equal(data.access_token, 'access');
+  assert.equal(calls, 2);
+});
+
+test('refresh does not retry on 400', async () => {
+  let calls = 0;
+  const fetchImpl = async () => {
+    calls += 1;
+    return mockResponse({ ok: false, status: 400, textData: 'bad request' });
+  };
+
+  await assert.rejects(
+    () => requestRefreshToken({
+      refreshUrl: 'https://example.com',
+      refreshToken: 'refresh_token',
+      clientId: 'client',
+      timeoutMs: 20,
+      maxRetries: 2,
+      retryDelayMs: 1,
+      fetchImpl
+    }),
+    (err) => err?.status === 400
+  );
+
+  assert.equal(calls, 1);
+});
+
+test('refresh retries on timeout abort', async () => {
+  let calls = 0;
+  const fetchImpl = async (url, options) => {
+    calls += 1;
+    return new Promise((resolve, reject) => {
+      if (!options?.signal) {
+        resolve(mockResponse({ ok: true, status: 200, jsonData: {} }));
+        return;
+      }
+      if (options.signal.aborted) {
+        const error = new Error('Aborted');
+        error.name = 'AbortError';
+        reject(error);
+        return;
+      }
+      options.signal.addEventListener('abort', () => {
+        const error = new Error('Aborted');
+        error.name = 'AbortError';
+        reject(error);
+      });
+    });
+  };
+
+  await assert.rejects(
+    () => requestRefreshToken({
+      refreshUrl: 'https://example.com',
+      refreshToken: 'refresh_token',
+      clientId: 'client',
+      timeoutMs: 5,
+      maxRetries: 1,
+      retryDelayMs: 1,
+      fetchImpl
+    }),
+    (err) => err?.name === 'AbortError'
+  );
+
+  assert.equal(calls, 2);
+});