add a test for xpack.banner config deprecations

x-pack/plugins/banners/server/config.test.ts

@@ -0,0 +1,38 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+import { config } from './config';
+import { getDeprecationsFor } from '../../../../src/core/server/test_utils';
+
+function applyDeprecations(settings?: Record<string, any>) {
+  return getDeprecationsFor({ provider: config.deprecations!, settings, path: 'xpack.banners' });
+}
+
+describe('deprecations', () => {
+  it('replaces xpack.banners.placement from "header" to "top"', () => {
+    const { migrated } = applyDeprecations({
+      placement: 'header',
+    });
+    expect(migrated.xpack.banners.placement).toBe('top');
+  });
+  it('logs a warning message about xpack.banners.placement renaming', () => {
+    const { messages } = applyDeprecations({
+      placement: 'header',
+    });
+    expect(messages).toMatchInlineSnapshot(`
+      Array [
+        "The \`header\` value for xpack.banners.placement has been replaced by \`top\`",
+      ]
+    `);
+  });
+  it('do not rename other placement values', () => {
+    const { migrated, messages } = applyDeprecations({
+      placement: 'disabled',
+    });
+    expect(migrated.xpack.banners.placement).toBe('disabled');
+    expect(messages.length).toBe(0);
+  });
+});