Updated answer for Angular CLI v6.x, 7.x, 8.x:
ng lint <project-name> --fix
where <project-name> is “name:” from package.json
— answer for Angular CLI v1.x —
ng lint -fix
— Original answer below —
To have tslint autofix many errors run the following in the root of your code. Obviously it can only autofix simpler issues like let -> const, “” -> ‘ etc.
npx tslint src/**/*.ts --fix
Yesterday I did this to auto-fix hundreds of let -> const issues in our fairly large code bases. Just reviewing the changes before committing took long enough, manually fixing them all would have taken over a day.