test(core): pin optional-by-default requestBody behavior (#2028)

PR #3263 changed packages/core/src/getters/body.ts to treat
`requestBody.required !== true` as optional, fixing the OpenAPI 3.0
optional-by-default behavior reported in #2028. That PR's title and
description don't mention #2028, so the rule isn't traceable from the
issue.

Lock down two specific cases that were not explicitly covered in
body.test.ts:

- The exact shape from #2028: an inline requestBody whose content schema
  is a $ref to components/schemas, with no `required` field. This
  case fails under the pre-#3263 `required !== undefined` rule and
  passes under the current `required !== true` rule.
- A $ref requestBody marked `required: false` (the explicit-false
  branch of components/requestBodies).

Author: wadakatu

packages/core/src/getters/body.test.ts

@@ -156,6 +156,71 @@ describe('getBody', () => {
 
     expect(result.isOptional).toBe(false);
   });
+
+  // Regression: #2028 — when an OpenAPI 3.0 spec leaves `required` off the
+  // requestBody, orval used to emit a required body parameter. The fix in
+  // PR #3263 treats `required !== true` as optional. This test pins the
+  // exact shape from #2028: an inline requestBody whose content schema is a
+  // `$ref` to components/schemas (not a $ref on the requestBody itself).
+  it('treats inline request bodies with a $ref schema and no required flag as optional (#2028)', () => {
+    const context = createContext();
+    context.spec.components = {
+      ...context.spec.components,
+      schemas: {
+        ...context.spec.components?.schemas,
+        BodyDto: {
+          type: 'object',
+          properties: {
+            x: { type: 'string' },
+          },
+        },
+      },
+    };
+
+    const result = getBody({
+      requestBody: {
+        content: {
+          'application/json': {
+            schema: { $ref: '#/components/schemas/BodyDto' },
+          },
+        },
+      },
+      operationName: 'createThing',
+      context,
+    });
+
+    expect(result.isOptional).toBe(true);
+  });
+
+  it('treats referenced request bodies marked required: false as optional', () => {
+    const context = createContext();
+    context.spec.components = {
+      ...context.spec.components,
+      requestBodies: {
+        SearchPetsBody: {
+          required: false,
+          content: {
+            'application/json': {
+              schema: {
+                type: 'object',
+                properties: {
+                  query: { type: 'string' },
+                },
+              },
+            },
+          },
+        },
+      },
+    };
+
+    const result = getBody({
+      requestBody: { $ref: '#/components/requestBodies/SearchPetsBody' },
+      operationName: 'searchPets',
+      context,
+    });
+
+    expect(result.isOptional).toBe(true);
+  });
 });
 
 describe('getBodiesByContentType', () => {