feat(oas3): respect optional responses in Operation Object

This is a change in OpenAPI 3.1.0

Author: kylef

packages/openapi3-parser/lib/context.js

@@ -36,6 +36,11 @@ class Context {
   hasScheme(id) {
     return this.state.hasScheme(id);
   }
+
+  // Versioning
+  isOpenAPIVersionLessThan(major, minor) {
+    return this.openapiVersion.major < major || (this.openapiVersion.major === major && this.openapiVersion.minor < minor);
+  }
 }
 
 module.exports = Context;

packages/openapi3-parser/lib/parser/oas/parseOperationObject.js

@@ -21,7 +21,6 @@ const parseReference = require('../parseReference');
 const parseRequestBodyObjectOrRef = parseReference('requestBodies', parseRequestBodyObject);
 
 const name = 'Operation Object';
-const requiredKeys = ['responses'];
 const unsupportedKeys = [
   'tags', 'externalDocs', 'callbacks', 'deprecated',
 ];
@@ -31,12 +30,16 @@ const isRequestBody = R.both(isMember, hasKey('requestBody'));
 
 function createTransactions(namespace, member, operation) {
   const requests = R.map(getValue, R.filter(isRequestBody, operation.content));
-  const responses = operation.get('responses');
+  const responses = R.or(operation.get('responses'), new namespace.elements.Array());
 
   if (requests.length === 0) {
     requests.push(new namespace.elements.HttpRequest());
   }
 
+  if (responses.length === 0) {
+    responses.push(new namespace.elements.HttpResponse());
+  }
+
   const transactions = [];
 
   requests.forEach((request) => {
@@ -123,6 +126,11 @@ function parseOperationObject(context, path, member) {
     ),
   ]));
 
+  const requiredKeys = [];
+  if (context.isOpenAPIVersionLessThan(3, 1)) {
+    requiredKeys.push('responses');
+  }
+
   const parseMember = R.cond([
     [hasKey('summary'), parseString(context, name, false)],
     [hasKey('description'), parseCopy(context, name, false)],

packages/openapi3-parser/test/unit/parser/oas/parseOperationObject-test.js

@@ -129,18 +129,6 @@ describe('Operation Object', () => {
     expect(parseResult).to.contain.warning("'Operation Object' contains invalid key 'invalid'");
   });
 
-  describe('missing required properties', () => {
-    it('provides error for missing responses', () => {
-      const operation = new namespace.elements.Member('get', {});
-
-      const parseResult = parse(context, path, operation);
-
-      expect(parseResult.length).to.equal(1);
-      expect(parseResult).to.contain.error("'Operation Object' is missing required property 'responses'");
-    });
-  });
-
-
   describe('#summary', () => {
     it('warns when summary is not a string', () => {
       const operation = new namespace.elements.Member('get', {
@@ -621,6 +609,26 @@ describe('Operation Object', () => {
   });
 
   describe('#responses', () => {
+    it('provides error for missing responses for OpenAPI 3.0', () => {
+      const operation = new namespace.elements.Member('get', {});
+
+      const parseResult = parse(context, path, operation);
+
+      expect(parseResult.length).to.equal(1);
+      expect(parseResult).to.contain.error("'Operation Object' is missing required property 'responses'");
+    });
+
+    it('does not require responses for OpenAPI >= 3.1', () => {
+      context.openapiVersion.minor = 1;
+      const operation = new namespace.elements.Member('get', {});
+
+      const parseResult = parse(context, path, operation);
+
+      expect(parseResult.length).to.equal(1);
+      const transition = parseResult.get(0);
+      expect(transition).to.be.instanceof(namespace.elements.Transition);
+    });
+
     it('returns a transition including a transaction', () => {
       const operation = new namespace.elements.Member('get', {
         responses: {