test(errors): add tests for ErrorToI18nKeyMapper

Signed-off-by: Erik Michelson <github@erik.michelson.eu>

frontend/src/api/common/error-to-i18n-key-mapper.spec.ts

@@ -0,0 +1,57 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { ApiError } from './api-error'
+import { ErrorToI18nKeyMapper } from './error-to-i18n-key-mapper'
+
+describe('ErrorToI18nKeyMapper', () => {
+  it('returns fallback with namespace when no mapper is defined', () => {
+    const mapper = new ErrorToI18nKeyMapper(new Error('test'), 'namespace')
+    const result = mapper.orFallbackI18nKey('fallback')
+    expect(result).toEqual('namespace.fallback')
+  })
+
+  it('returns fallback without namespace when no mapper is defined and absolute key should be used', () => {
+    const mapper = new ErrorToI18nKeyMapper(new Error('test'), 'namespace')
+    const result = mapper.orFallbackI18nKey('fallback', true)
+    expect(result).toEqual('fallback')
+  })
+
+  it('returns undefined when no mapper is defined and no fallback defined', () => {
+    const mapper = new ErrorToI18nKeyMapper(new Error('test'), 'namespace')
+    const result = mapper.orFallbackI18nKey(undefined)
+    expect(result).toEqual(undefined)
+  })
+
+  it('maps an error by its error message to an i18n key', () => {
+    const mapper = new ErrorToI18nKeyMapper(new Error('test'), 'namespace')
+    const result = mapper
+      .withBackendErrorName('BackendError', 'backendError')
+      .withErrorMessage('test', 'testError')
+      .withHttpCode(418, 'teapot')
+      .orFallbackI18nKey('fallback')
+    expect(result).toEqual('namespace.testError')
+  })
+
+  it('maps an API error by its error name to an i18n key', () => {
+    const mapper = new ErrorToI18nKeyMapper(new ApiError(500, 'BackendError'), 'namespace')
+    const result = mapper
+      .withBackendErrorName('BackendError', 'backendError')
+      .withErrorMessage('test', 'testError')
+      .withHttpCode(418, 'teapot')
+      .orFallbackI18nKey('fallback')
+    expect(result).toEqual('namespace.backendError')
+  })
+
+  it('maps an API error by its status code to an i18n key', () => {
+    const mapper = new ErrorToI18nKeyMapper(new ApiError(418, 'Coffee'), 'namespace')
+    const result = mapper
+      .withBackendErrorName('BackendError', 'backendError')
+      .withErrorMessage('test', 'testError')
+      .withHttpCode(418, 'teapot')
+      .orFallbackI18nKey('fallback')
+    expect(result).toEqual('namespace.teapot')
+  })
+})