Update dataSource after updated a row

I’m trying to update my dataTable when an user has been edited.

At the moment, the dataSource is updated, but changes are not visible on front part. I mean, my console.log(this.dataSource) show good datas. But on the web page it’s not the case.

Here’s how I get my dataSource (ngOnInit) :

this.users.users().subscribe(data => {
    this.dataSource.data = data;

Here’s my update function :

* Update an user
* @param user The user to update
  update(user: User) {
    // users = user's services
      userEdited => {
        const userIndex = this.dataSource.data.findIndex(usr => usr.id === user.id);

        console.log('Before change :', this.dataSource.data[userIndex], userIndex);

        this.dataSource.data[userIndex] = userEdited;

        console.log('After change :', this.dataSource.data[userIndex], this.dataSource.data);

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Source Url Update dataSource after updated a row