Validate function not called in redux-form - reactjs

Question

I am using redux-form 6.3 version and in this validate function getting called. below is my code. Please check what is issue in code.
Also is there any need to do changes related to validation in actions
import React, { Component } from 'react';
import { Field, reduxForm, initialize } from 'redux-form';
import { connect } from 'react-redux';
import * as actions from '../../actions';
const renderField = field => (
<div className="form-group">
<label>{field.input.label}</label>
<input {...field.input} value={field.value} onChange={(e)=> console.log(e.target.value) } />
{field.touched && field.error && <div className="error">{field.error}</div>}
</div>
);
const renderSelect = field => (
<div>
<label>{field.input.label}</label>
<select {...field.input}/>
{field.touched && field.error && <div className="error">{field.error}</div>}
</div>
);
function validate(formProps) {console.log("vvv---", formProps);
const errors = {};
if (!formProps.firstName) {
errors.firstName = 'Please enter a first name';
}
if (!formProps.lastName) {
errors.lastName = 'Please enter a last name';
}
if (!formProps.email) {
errors.email = 'Please enter an email';
}
if (!formProps.phoneNumber) {
errors.phoneNumber = 'Please enter a phone number'
}
if(!formProps.sex) {
errors.sex = 'You must enter your sex!'
}
return errors;
}
class ReduxFormTutorial extends Component {
componentDidMount() {
this.handleInitialize();
}
handleInitialize() {
const initData = {
"firstName": "Puneet",
"lastName": "Bhandari",
"sex": "male",
"email": "test#gmail.com",
"phoneNumber": "23424234"
};
this.props.initialize(initData);
}
handleFormSubmit(formProps) {
//console.log(formProps);
this.state = { firstName : null };
this.props.submitFormAction(formProps);
}
//our other functions will go here
render() {
const { fields : [firstName, lastName], handleSubmit } = this.props;
return (
<div>
<form onSubmit={handleSubmit(this.handleFormSubmit.bind(this))}>
<Field name="firstName" value="" type="text" component={renderField} label="First Name" />
<Field name="lastName" value="" type="text" component={renderField} label="Last Name"/>
<Field name="sex" component={renderSelect} label="Gender">
<option></option>
<option name="male">Male</option>
<option name="female">Female</option>
</Field>
<Field name="email" type="email" component={renderField} label="Email" />
<Field name="phoneNumber" type="tel" component={renderField} label="Phone Number"/>
<button action="submit">Save changes</button>
</form>
</div>
)
}
}
const form = reduxForm({
form: 'ReduxFormTutorial',
fields: [ 'firstName', 'lastName' ],
validate
});
function mapStateToProps(state) {
return {
user: state.user
};
}
export default connect(mapStateToProps, actions)(form(ReduxFormTutorial));