fix: fix custom http resolvers for AsyncAPI widget

Signed-off-by: David Weber <david.weber@w3tec.ch>

.changeset/blue-hats-admire.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-api-docs': patch
+---
+
+Fix custom http resolvers for AsyncAPI widget.

plugins/api-docs/src/components/AsyncApiDefinitionWidget/AsyncApiDefinition.tsx

@@ -143,18 +143,33 @@ const useStyles = makeStyles(theme => ({
   },
 }));
 
-const fetchResolver = {
-  order: 199, // Use 199 as the built-in http resolver is 200
-  canRead: /^https?:\/\//,
-  async read(file: any) {
-    const response = await fetch(file.url);
+const httpsFetchResolver = {
+  schema: 'https',
+  order: 1,
+  canRead: true,
+  async read(uri: any) {
+    const response = await fetch(uri.toString());
+    return response.text();
+  },
+};
+
+const httpFetchResolver = {
+  schema: 'http',
+  order: 1,
+  canRead: true,
+  async read(uri: any) {
+    const response = await fetch(uri.toString());
     return response.text();
   },
 };
 
 const config = {
   parserOptions: {
-    resolve: { fetch: fetchResolver },
+    __unstable: {
+      resolver: {
+        resolvers: [httpsFetchResolver, httpFetchResolver],
+      },
+    },
   },
 };