chore: support for additional media (#3247)

## About the changes
Add new methods to simplify the creation of schemas for endpoints with
additional media types (other than `application/json`)

This is a follow-up on exporting an endpoint as `text/csv`

src/lib/openapi/util/create-response-schema.test.ts

@@ -1,4 +1,9 @@
-import { createResponseSchema } from './create-response-schema';
+import {
+    createResponseSchema,
+    createResponseSchemas,
+    schemaNamed,
+    schemaTyped,
+} from './create-response-schema';
 
 test('createResponseSchema', () => {
     expect(createResponseSchema('schemaName')).toMatchInlineSnapshot(`
@@ -14,3 +19,28 @@ test('createResponseSchema', () => {
         }
     `);
 });
+
+test('createResponseSchemaWithDifferentMedia', () => {
+    expect(
+        createResponseSchemas('my-schema', {
+            'application/json': schemaNamed('schemaName'),
+            'text/css': schemaTyped('string'),
+        }),
+    ).toMatchInlineSnapshot(`
+      {
+        "content": {
+          "application/json": {
+            "schema": {
+              "$ref": "#/components/schemas/schemaName",
+            },
+          },
+          "text/css": {
+            "schema": {
+              "type": "string",
+            },
+          },
+        },
+        "description": "my-schema",
+      }
+  `);
+});

src/lib/openapi/util/create-response-schema.ts

@@ -1,18 +1,39 @@
 import { OpenAPIV3 } from 'openapi-types';
 
+export const createResponseSchemas = (
+    description: string,
+    content: { [media: string]: OpenAPIV3.MediaTypeObject },
+): OpenAPIV3.ResponseObject => {
+    return {
+        description,
+        content: content,
+    };
+};
+
+export const schemaNamed = (schemaName: string): OpenAPIV3.MediaTypeObject => {
+    return {
+        schema: {
+            $ref: `#/components/schemas/${schemaName}`,
+        },
+    };
+};
+
+export const schemaTyped = (
+    type: OpenAPIV3.NonArraySchemaObjectType,
+): OpenAPIV3.MediaTypeObject => {
+    return {
+        schema: {
+            type,
+        },
+    };
+};
+
 export const createResponseSchema = (
     schemaName: string,
 ): OpenAPIV3.ResponseObject => {
-    return {
+    return createResponseSchemas(schemaName, {
-        description: schemaName,
+        'application/json': schemaNamed(schemaName),
-        content: {
+    });
-            'application/json': {
-                schema: {
-                    $ref: `#/components/schemas/${schemaName}`,
-                },
-            },
-        },
-    };
 };
 
 export const resourceCreatedResponseSchema = (