fix(#4189): add content type validation for mappings component (#4197)

Author: SteKoe

spring-boot-admin-server-ui/src/main/frontend/views/instances/mappings/index.spec.ts

@@ -1,4 +1,5 @@
 import { screen, waitFor } from '@testing-library/vue';
+import { shallowMount } from '@vue/test-utils';
 import { describe, expect, it, vi } from 'vitest';
 
 import Mappings from './index.vue';
@@ -77,6 +78,39 @@ describe('Mappings', () => {
     expect(element).toBeVisible();
   });
 
+  it.each`
+    contentType
+    ${'application/vnd.spring-boot.actuator.v2+json'}
+    ${'application/vnd.spring-boot.actuator.v3+json'}
+    ${'application/vnd.spring-boot.actuator.v2+json;charset=UTF-8'}
+    ${'application/vnd.spring-boot.actuator.v3+json;charset=UTF-8'}
+  `('should accept allowed content type headers', ({ contentType }) => {
+    const wrapper = shallowMount(Mappings, {
+      props: {
+        instance: createInstanceWithMappingsData(mappings),
+      },
+    });
+
+    expect(wrapper.vm.isSupportedContextType(contentType)).toBe(true);
+  });
+
+  it.each`
+    contentType
+    ${'application/vnd.spring-boot.actuator.v+json'}
+    ${'application/vnd.spring-boot.actuator.v34+json'}
+    ${'invalid'}
+    ${null}
+    ${undefined}
+  `('should reject content type headers', ({ contentType }) => {
+    const wrapper = shallowMount(Mappings, {
+      props: {
+        instance: createInstanceWithMappingsData(mappings),
+      },
+    });
+
+    expect(wrapper.vm.isSupportedContextType(contentType)).toBe(false);
+  });
+
   // Helpers
   function renderWithInstance(data) {
     render(Mappings, {

spring-boot-admin-server-ui/src/main/frontend/views/instances/mappings/index.vue

@@ -98,15 +98,21 @@ export default {
     hasServletFilters(context) {
       return context?.mappings?.servletFilters !== undefined;
     },
+    isSupportedContextType(contentType) {
+      const supportedContentTypes = [
+        'application/vnd.spring-boot.actuator.v3+json',
+        'application/vnd.spring-boot.actuator.v2+json',
+      ];
+
+      return !!supportedContentTypes.find((supportedContentType) =>
+        (contentType || '').includes(supportedContentType),
+      );
+    },
     async fetchMappings() {
       this.error = null;
       try {
         const res = await this.instance.fetchMappings();
-        const supportedContentTypes = [
-          'application/vnd.spring-boot.actuator.v3+json',
-          'application/vnd.spring-boot.actuator.v2+json',
-        ];
-        if (supportedContentTypes.includes(res.headers['content-type'])) {
+        if (this.isSupportedContextType(res.headers['content-type'])) {
           this.contexts = res.data.contexts;
         } else {
           this.isOldMetrics = true;