pass matching mime type to xmldom; test [dynamicxml] (#10830)

* feat: pass matching mime type to xmldom

If the `Content-Type` header contains one of the mime types supported by `DOMParser`, the first matching mime type will be used instead of `text/xml`.

The default is still `text/xml` for cases when the header is not present or none of the mime types from the list are present.

* factor out and add tests

---------

Co-authored-by: chris48s <git@chris-shaw.dev>

services/dynamic/dynamic-xml.service.js

@@ -1,4 +1,4 @@
-import { DOMParser } from '@xmldom/xmldom'
+import { DOMParser, MIME_TYPE } from '@xmldom/xmldom'
 import xpath from 'xpath'
 import { MetricNames } from '../../core/base-service/metric-helper.js'
 import { renderDynamicBadge, httpErrors } from '../dynamic-common.js'
@@ -10,6 +10,8 @@ import {
 } from '../index.js'
 import { createRoute } from './dynamic-helpers.js'
 
+const MIME_TYPES = Object.values(MIME_TYPE)
+
 const description = `
 The Dynamic XML Badge allows you to extract an arbitrary value from any
 XML Document using an XPath selector and show it on a badge.
@@ -70,6 +72,10 @@ export default class DynamicXml extends BaseService {
 
   static defaultBadgeData = { label: 'custom badge' }
 
+  getmimeType(contentType) {
+    return MIME_TYPES.find(mime => contentType.includes(mime)) ?? 'text/xml'
+  }
+
   transform({ pathExpression, buffer, contentType = 'text/xml' }) {
     // e.g. //book[2]/@id
     const pathIsAttr = (
@@ -136,11 +142,8 @@ export default class DynamicXml extends BaseService {
     })
 
     let contentType = 'text/xml'
-    if (
-      res.headers['content-type'] &&
-      res.headers['content-type'].includes('text/html')
-    ) {
-      contentType = 'text/html'
+    if (res.headers['content-type']) {
+      contentType = this.getmimeType(res.headers['content-type'])
     }
 
     const { values: value } = this.transform({

services/dynamic/dynamic-xml.spec.js

@@ -157,4 +157,19 @@ describe('DynamicXml', function () {
       values: ['Herman Melville - Moby-Dick'],
     })
   })
+
+  test(DynamicXml.prototype.getmimeType, () => {
+    // known types
+    given('text/html').expect('text/html')
+    given('application/xml').expect('application/xml')
+    given('application/xhtml+xml').expect('application/xhtml+xml')
+    given('image/svg+xml').expect('image/svg+xml')
+
+    // with character set
+    given('text/html; charset=utf-8').expect('text/html')
+
+    // should fall back to text/xml if mime type is not one of the known types
+    given('text/csv').expect('text/xml')
+    given('foobar').expect('text/xml')
+  })
 })