fix: allow null values for default property (#227)

Author: Christian Compton

src/plugins/validation/2and3/semantic-validators/walker-ibm.js

@@ -52,7 +52,7 @@ module.exports.validate = function({ jsSpec, resolvedSpec }, config) {
 
     // check for and flag null values - they are not allowed by the spec and are likely mistakes
     Object.keys(obj).forEach(key => {
-      if (obj[key] === null) {
+      if (key !== 'default' && obj[key] === null) {
         messages.addMessage(
           [...path, key],
           'Null values are not allowed for any property.',

test/plugins/validation/2and3/walker-ibm.test.js

@@ -97,7 +97,7 @@ describe('validation plugin - semantic - walker-ibm', () => {
     expect(res.warnings.length).toEqual(0);
   });
 
-  it('should return an error when a property contains a null value', () => {
+  it('should return an error when a non-default property contains a null value', () => {
     const spec = {
       paths: {
         '/pets': {
@@ -131,6 +131,29 @@ describe('validation plugin - semantic - walker-ibm', () => {
     expect(res.warnings.length).toEqual(0);
   });
 
+  it('should not return an error when the default property contains a null value', () => {
+    const spec = {
+      paths: {
+        '/pets': {
+          get: {
+            parameters: [
+              {
+                name: 'tags',
+                in: 'query',
+                default: null,
+                type: 'string'
+              }
+            ]
+          }
+        }
+      }
+    };
+
+    const res = validate({ jsSpec: spec }, config);
+    expect(res.errors.length).toEqual(0);
+    expect(res.warnings.length).toEqual(0);
+  });
+
   it('should complain if a description sibling to a $ref matches the referenced schema description', async () => {
     const spec = {
       paths: {