fix: null typecheck in parameter validation (#849)

Author: attilaorosz

src/ActionParameterHandler.ts

@@ -64,7 +64,7 @@ export class ActionParameterHandler<T extends BaseDriver> {
     // check cases when parameter is required but its empty and throw errors in this case
     if (param.required) {
       const isValueEmpty = value === null || value === undefined || value === '';
-      const isValueEmptyObject = typeof value === 'object' && Object.keys(value).length === 0;
+      const isValueEmptyObject = typeof value === 'object' && value !== null && Object.keys(value).length === 0;
 
       if (param.type === 'body' && !param.name && (isValueEmpty || isValueEmptyObject)) {
         // body has a special check and error message

test/ActionParameterHandler.spec.ts

@@ -115,6 +115,26 @@ describe('ActionParameterHandler', () => {
 
       expect(processedValue).to.be.eq(undefined);
     });
+
+    it('handle - null provided', async () => {
+      try {
+        const param = buildParamMetadata('id', 'param', true);
+        const action = {
+          request: {
+            params: {
+              id: null,
+            },
+          },
+          response: {},
+        };
+
+        await actionParameterHandler.handle(action, param);
+      } catch (error) {
+        expect(error.toString()).to.be.eq(
+          'ParamRequiredError: Parameter "id" is required for request on undefined undefined'
+        );
+      }
+    });
   });
   describe('negative', () => {
     it('handle - throws error if the parameter is required', async () => {