Q:

Can't receive Async response in componentDidMount with Redux

lately i'm facing a tough issue with React/Redux (Thunk): i've created my Store with Action and Reducer properly, in my Component i trigger the Async function in componentDidMount method in order to update the state, But the State doesn't seems to be changing, although it does changed in componentDidUpdate and mapStateToProps functions !  Why ?  Here is my code :
export const getAllInterventions = () => {
return dispatch => {
    dispatch(getAllDataStart());
    axios.get('/interventions.json')
        .then(res => {
            dispatch(getAllDataSuccess(res.data));
        })
        .catch(err => {
            dispatch(getAllDataFail(err));
        });
};

My reducer : 
case actionTypes. GET_ALL_INTERVENTIONS_SUCCESS:
        return {
            ...state,
            interventions: interventions: action.interventions
        };

My Component: 
    componentDidMount() {
    this.props.getAllInterventions();
    console.log('DidMount: ', this.props.inter); /*Empty Array Or Undefined */
}

const mapStateToProps = state => {
console.log('mapStateToProps', state);
return {
    inter: state.interventions,
    error: state.error
};

A:

Your action and state changes are both asynchronous, doing console.log right after will always return before those changes are actually completed.  
Your state is being updated, which is why it works when you console.log in the mapStateToProps. 
I suggest setting up redux-devtools, you'll be able to easily track your actions/state.