diff --git a/packages/api/src/context/readConfigFile.test.js b/packages/api/src/context/readConfigFile.test.js
new file mode 100644
index 000000000..26db8d884
--- /dev/null
+++ b/packages/api/src/context/readConfigFile.test.js
@@ -0,0 +1,33 @@
+/*
+  Copyright 2020-2021 Lowdefy, Inc
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+
+import { getFileExtension } from '@lowdefy/node-utils';
+
+jest.mock('@lowdefy/node-utils', () => {
+  return {
+    getFileExtension,
+    readFile: jest.fn(),
+  };
+});
+
+test('readConfigFile', async () => {
+  const nodeUtils = await import('@lowdefy/node-utils');
+  nodeUtils.mockImplementation(() => Promise.resove('config value'));
+  const createReadConfigFile = (await import('./readConfigFile.js')).default;
+  const readConfigFile = createReadConfigFile({ buildDirectory: '/build' });
+  const res = await readConfigFile('file');
+  expect(res).toEqual('config value');
+});
diff --git a/packages/utils/helpers/src/cachedPromises.js b/packages/utils/helpers/src/cachedPromises.js
index 63de5868d..1a56d46b6 100644
--- a/packages/utils/helpers/src/cachedPromises.js
+++ b/packages/utils/helpers/src/cachedPromises.js
@@ -14,10 +14,10 @@
   limitations under the License.
 */
 
-function cachedPromises(getter) {
+function createCachedPromises(getter) {
   const cache = new Map();
 
-  function getCachedPromise(key) {
+  function cachedPromises(key) {
     if (cache.has(key)) {
       return Promise.resolve(cache.get(key));
     }
@@ -26,7 +26,7 @@ function cachedPromises(getter) {
     return Promise.resolve(promise);
   }
 
-  return getCachedPromise;
+  return cachedPromises;
 }
 
-export default cachedPromises;
+export default createCachedPromises;
diff --git a/packages/utils/helpers/src/cachedPromises.test.js b/packages/utils/helpers/src/cachedPromises.test.js
new file mode 100644
index 000000000..38d44243e
--- /dev/null
+++ b/packages/utils/helpers/src/cachedPromises.test.js
@@ -0,0 +1,52 @@
+/*
+  Copyright 2020-2021 Lowdefy, Inc
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+
+import createCachedPromises from './cachedPromises.js';
+import wait from './wait.js';
+
+test('cachedPromises calls getter with key', async () => {
+  const getter = jest.fn(() => Promise.resolve('value'));
+  const cachedGetter = createCachedPromises(getter);
+  const promise = cachedGetter('key');
+  expect(`${promise}`).toEqual('[object Promise]');
+  const result = await promise;
+  expect(result).toEqual('value');
+  expect(getter.mock.calls).toEqual([['key']]);
+});
+
+test('cachedPromises only calls getter once', async () => {
+  const getter = jest.fn(() => Promise.resolve('value'));
+  const cachedGetter = createCachedPromises(getter);
+  const result1 = await cachedGetter('key');
+  expect(result1).toEqual('value');
+  const result2 = await cachedGetter('key');
+  expect(result2).toEqual('value');
+  expect(getter.mock.calls).toEqual([['key']]);
+});
+
+test('getter is called once if first call has not yet resolved', async () => {
+  const getter = jest.fn(async () => {
+    await wait(10);
+    return 'value';
+  });
+  const cachedGetter = createCachedPromises(getter);
+  const promise1 = cachedGetter('key');
+  const promise2 = cachedGetter('key');
+  expect(getter.mock.calls).toEqual([['key']]);
+  await promise1;
+  await promise2;
+  expect(getter.mock.calls).toEqual([['key']]);
+});