chore(front-end): fix jest reporter

修复因 jest 使用 stderr 输出警告而导致的 CI 执行失败
microsoft/rushstack#1329

apps/front-end/jest.config.js

@@ -2,6 +2,7 @@
 const config = {
   verbose: true,
   setupFilesAfterEnv: ['<rootDir>/src/setupTests.ts'],
+  reporters: ['./src/JestReporter.js'],
   testMatch: ['**/src/**/*.test.ts?(x)'],
   transform: {
     '^.+\\.[jt]sx?$': 'babel-jest',

apps/front-end/src/JestReporter.js

@@ -0,0 +1,28 @@
+// This doesn't have types for some reason
+// eslint-disable-next-line @typescript-eslint/no-var-requires
+const { DefaultReporter } = require('@jest/reporters')
+
+/**
+ * The purpose of this custom reporter is to prevent Jest from logging to stderr
+ * when there are no errors.
+ */
+class JestReporter extends DefaultReporter {
+  _isLoggingError = false
+
+  log(message) {
+    if (this._isLoggingError) {
+      process.stderr.write(message + '\n')
+    } else {
+      process.stdout.write(message + '\n')
+    }
+  }
+
+  printTestFileFailureMessage(...args) {
+    this._isLoggingError = true
+    super.printTestFileFailureMessage(...args)
+    this._isLoggingError = false
+  }
+}
+
+// jest needs this format
+module.exports = JestReporter