Automatically close empty “Staged/Unchaged Changes” tabs in Atom

init.js

// Close "Staged/Unstaged Changes" tabs when they become empty.
const EmptyMonitor = {
  metaForElement: new Map(),
  observerOptions: {
    childList: false,
    attributes: true,
    subtree: false,
    attributeFilter: ['class']
  },

  checkAll (panes) {
    for (let pane of panes) {
      let items = pane.getItems();
      for (let item of items) {
        if (!this.isFilePatchView(item)) { continue; }
        let element = this.getElementForItem(item);
        if (!element) { return; }
        if (!this.isEmpty(item)) { return; }
        this.forget(item, element);
        pane.destroyItem(item);
      }
    }
  },

  getElementForItem (item) {
    let element;
    try {
      element = item.getElement().querySelector('.github-FilePatchView');
    } catch (err) {
      console.error(err);
      return null;
    }
    return element || null;
  },

  isFilePatchView (item) {
    if (!('getURI' in item)) { return false; }
    let uri = item.getURI();
    if (!uri || typeof uri !== 'string') { return false; }
    return uri.startsWith('atom-github://file-patch/');
  },

  isEmpty (item, element = null) {
    if (!element) { element = this.getElementForItem(item); }
    return element.classList.contains('github-FilePatchView--blank');
  },

  remember (item, pane, element = null) {
    if (!element) { element = this.getElementForItem(item); }
    if (!element) { return; }
    return this.metaForElement.set(element, { item, pane });
  },

  forget (item, element = null) {
    if (!element) { element = this.getElementForItem(item); }
    if (!element) { return; }
    return this.metaForElement.delete(element);
  },

  checkForEmpty (item, element = null) {
    if (!element) { element = this.getElementForItem(item); }
    if (!this.isEmpty(item, element)) { return; }
    if (!this.metaForElement.has(element)) { return; }
    let { pane } = this.metaForElement.get(element);
    this.forget(item, element);
    pane.destroyItem(item);
  },

  setup () {
    this._observer = new MutationObserver(
      mutations => {
        let panes = new Set();
        for (let mutation of mutations) {
          let bundle = this.metaForElement.get(mutation.target);
          if (!bundle) { continue; }
          panes.add(bundle.pane);
        }
        setTimeout(this.checkAll.bind(this, panes), 50);
      }
    );
  },

  closeOnEmpty (item, pane, retry = true) {
    if (!this._observer) { this.setup(); }
    let element = this.getElementForItem(item);
    if (!element && retry) {
      setTimeout(() => this.closeOnEmpty(item, pane, false), 100);
      return;
    }
    this.remember(item, pane, element);
    this._observer.observe(element, this.observerOptions);
    setTimeout(() => this.checkForEmpty(item, element), 50);
  },

  observeIfFilePatchView (item, pane) {
    if (!this.isFilePatchView(item)) { return; }
    setTimeout(() => this.closeOnEmpty(item, pane), 100);
  }
};

atom.workspace.observePanes(
  pane => {
    pane.onDidAddItem(({ item }) => {
      EmptyMonitor.observeIfFilePatchView(item, pane);
    });
  }
);