extension.js

var vscode = require("vscode");
var history = [];
var historyPosition = 0;
var historyMaxSize = 50;
var lastEditLocation;
var editGroupTimeThreshold = 500;
var lastEditTime;

function _onEvent(e) {
  var lastChangeTooRecent = Date.now() - lastEditTime < editGroupTimeThreshold;
  var isOnSameLine =
    lastEditLocation &&
    getEventPosition(e).range.end.line === lastEditLocation.position.end.line;
  if (!lastChangeTooRecent && !isOnSameLine && isValidEditFile(e)) {
    saveChangePosition(e);
  }
}

function isValidEditFile(e) {
  var isGitRelatedChange = e.document.uri._scheme === "git";
  var isOutpuTabChange = e.document.uri.scheme === "output";
  return !isOutpuTabChange && !isGitRelatedChange;
}

function getEventPosition(event) {
  return event.contentChanges[event.contentChanges.length - 1];
}

function saveChangePosition(event) {
  lastEditLocation = {
    position: getEventPosition(event).range,
    file: event.document.uri.path
  };
  lastEditTime = Date.now();
  if (history.length >= historyMaxSize) {
    var elementsToRemove = history.length - historyMaxSize + 1;
    history.splice(0, elementsToRemove);
  }
  history.push(lastEditLocation);
  historyPosition = history.length;
}

function scrollToLocation(editor, edit) {
  editor.revealRange(edit.position);
  editor.selection = new vscode.Selection(
    edit.position.start,
    edit.position.end
  );
}

function navigate(goingBack) {
  if (history.length > 0) {
    lastEditLocation = goingBack
      ? history[historyPosition - 1]
      : history[historyPosition + 1];
    if (lastEditLocation) {
      historyPosition = goingBack ? historyPosition - 1 : historyPosition + 1;
    } else {
      lastEditLocation = goingBack ? history[0] : history[history.length - 1];
    }
    openOrShowLocation(lastEditLocation);
    vscode.window.setStatusBarMessage(
      `Edit ${historyPosition + 1} of ${history.length}`,
      1500
    );
  }
}

function openOrShowLocation(location) {
  var lastEditEditorFound = vscode.workspace.textDocuments.find(function(item) {
    return item.fileName === location.file;
  });
  if (lastEditEditorFound) {
    vscode.window.showTextDocument(lastEditEditorFound).then(function(editor) {
      scrollToLocation(editor, location);
    });
  } else {
    vscode.workspace
      .openTextDocument(location.file)
      .then(vscode.window.showTextDocument)
      .then(function(editor) {
        scrollToLocation(editor, location);
      });
  }
}

module.exports = {
  activate: function(context) {
    var disposable = vscode.workspace.onDidChangeTextDocument(_onEvent);
    var goBack = vscode.commands.registerCommand(
      "gotoLastEdit.goBack",
      function() {
        navigate(true);
      }
    );
    var goForward = vscode.commands.registerCommand(
      "gotoLastEdit.goForward",
      function() {
        navigate(false);
      }
    );

    context.subscriptions.push(disposable, goBack, goForward);
  }
};