core: added logCollector test util

packages/core/src/testUtils/index.js

@@ -27,6 +27,7 @@ import { render } from '@testing-library/react';
 
 export { default as Keyboard } from './Keyboard';
 export { default as mockBreakpoint } from './mockBreakpoint';
+export * from './logCollector';
 
 export function wrapInTestApp(Component, initialRouterEntries) {
   const Wrapper = Component instanceof Function ? Component : () => Component;

packages/core/src/testUtils/logCollector.js

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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.
+ */
+
+/* eslint-disable no-console */
+
+// If the callback function is async this one will be too.
+export function withLogCollector(logsToCollect, callback) {
+  if (typeof logsToCollect === 'function') {
+    callback = logsToCollect;
+    logsToCollect = ['log', 'warn', 'error'];
+  }
+  const logs = {
+    log: [],
+    warn: [],
+    error: [],
+  };
+
+  const origLog = console.log;
+  const origWarn = console.warn;
+  const origError = console.error;
+
+  if (logsToCollect.includes('log')) {
+    console.log = message => {
+      logs.log.push(message);
+    };
+  }
+  if (logsToCollect.includes('warn')) {
+    console.warn = message => {
+      logs.warn.push(message);
+    };
+  }
+  if (logsToCollect.includes('error')) {
+    console.error = message => {
+      logs.error.push(message);
+    };
+  }
+
+  const restore = () => {
+    console.log = origLog;
+    console.warn = origWarn;
+    console.error = origError;
+  };
+
+  try {
+    const ret = callback();
+
+    if (!ret || !ret.then) {
+      restore();
+      return logs;
+    }
+
+    return ret.then(
+      () => {
+        restore();
+        return logs;
+      },
+      error => {
+        restore();
+        throw error;
+      },
+    );
+  } catch (error) {
+    restore();
+    throw error;
+  }
+}