Merge pull request #46 from tiaanduplessis/master

Author: Larry Botha

lib/create-form.js

@@ -83,7 +83,9 @@ export const createForm = (config) => {
       isValidating.set(true);
       return Promise.resolve()
         .then(() => validateFn({[field]: value}))
-        .then((errs) => util.update(errors, field, errs[field]))
+        .then((errs) =>
+          util.update(errors, field, !util.isNullish(errs) ? errs[field] : ''),
+        )
         .finally(() => {
           isValidating.set(false);
         });

lib/util.js

@@ -17,8 +17,12 @@ function cloneDeep(object) {
   return JSON.parse(JSON.stringify(object));
 }
 
+function isNullish(value) {
+  return value === undefined || value === null;
+}
+
 function isEmpty(object) {
-  return Object.keys(object).length <= 0;
+  return isNullish(object) || Object.keys(object).length <= 0;
 }
 
 function getValues(object) {
@@ -127,4 +131,5 @@ export const util = {
   reach,
   subscribeOnce,
   update,
+  isNullish,
 };

test/lib.spec.js

@@ -257,6 +257,29 @@ describe("createForm", () => {
         .then(errors => expect(errors.email).toBe("this email is invalid"))
         .then(done);
     });
+
+    it("assigns empty string to field if validateFn returns undefined", done => {
+      const value = "[email protected]";
+      const event = {
+        target: {
+          name: "email",
+          value
+        }
+      };
+      const instance = createForm({
+        initialValues: {
+          email: ""
+        },
+        validate: values => undefined,
+        onSubmit: values => console.log(values)
+      });
+
+      instance
+        .handleChange(event)
+        .then(() => subscribeOnce(instance.errors))
+        .then(errors => expect(errors.email).toBe(""))
+        .then(done);  
+    })
   });
 
   describe("handleSubmit", () => {