Additional test and readme updates

README.md

@@ -569,6 +569,21 @@ Determines whether the validator should validate responses. Also accepts respons
   }
   ```
 
+  **onError:**
+
+  A function that will be invoked on response validation error, instead of the default handling. Useful if you want to log an error or emit a metric, but don't want to actually fail the request. Receives the validation error and offending response body.
+
+  For example:
+
+  ```
+  validateResponses: {
+    onError: (error, body) => {
+      console.log(`Response body fails validation: `, error);
+      console.debug(body);
+    }
+  }
+  ```
+
 ### ▪️ validateSecurity (optional)
 
 Determines whether the validator should validate securities e.g. apikey, basic, oauth2, openid, etc

test/response.validation.on.error.spec.ts

@@ -16,8 +16,11 @@ describe(packageJson.name, () => {
       {
         apiSpec: apiSpecPath,
         validateResponses: {
-          onError: function() {
+          onError: function(_err, body) {
             onErrorArgs = Array.from(arguments);
+            if (body[0].id === 'bad_id_throw') {
+              throw new Error('error in onError handler');
+            }
           }
         },
       },
@@ -29,8 +32,10 @@ describe(packageJson.name, () => {
         });
         app.get(`${app.basePath}/pets`, (req, res) => {
           let json = {};
-          if ((req.query.mode = 'bad_type')) {
+          if (req.query.mode === 'bad_type') {
             json = [{ id: 'bad_id', name: 'name', tag: 'tag' }];
+          } else if (req.query.mode === 'bad_type_throw') {
+            json = [{ id: 'bad_id_throw', name: 'name', tag: 'tag' }];
           }
           return res.json(json);
         });
@@ -73,4 +78,16 @@ describe(packageJson.name, () => {
         expect(r.body).is.an('array').with.length(3);
         expect(onErrorArgs).to.equal(null);
       }));
+
+  it('returns error if custom error handler throws', async () =>
+    request(app)
+      .get(`${app.basePath}/pets?mode=bad_type_throw`)
+      .expect(500)
+      .then((r: any) => {
+        const data = [{ id: 'bad_id_throw', name: 'name', tag: 'tag' }];
+        expect(r.body.message).to.equal('error in onError handler');
+        expect(onErrorArgs.length).to.equal(2);
+        expect(onErrorArgs[0].message).to.equal('.response[0].id should be integer');
+        expect(onErrorArgs[1]).to.eql(data);
+      }));
 });