Before (Set indent options):
  set shiftwidth=2

Given tex (Indent regular tex):
  \documentclass{minimal}
  \usepackage{amsmath}
  \usepackage{tikz}
  \begin{document}

  {
      asdasd
    }

    \end{document}

Do:
  gg=G

Expect tex:
  \documentclass{minimal}
  \usepackage{amsmath}
  \usepackage{tikz}
  \begin{document}

  {
    asdasd
  }

  \end{document}

Given tex (Indent lists):
  \begin{itemize}
  \item item is indented twice
        and the next line is indented to match
  \end{itemize}

  \begin{description}
    \item[One] Ingeniería Electrónica ``first'';
    a couple of lines.
  \item[Doctorado] ``Generic title''
    (Author): commentaries here
  \end{description}

Do:
  gg=G

Expect tex:
  \begin{itemize}
    \item item is indented twice
      and the next line is indented to match
  \end{itemize}

  \begin{description}
    \item[One] Ingeniería Electrónica ``first'';
      a couple of lines.
    \item[Doctorado] ``Generic title''
      (Author): commentaries here
  \end{description}

Given tex (Indent math):
      \[
    1+1
        \]

  \begin{align}
      2+2=4
  \end{align}

  \begin{equation}
     \left(
       f(x) = 3
    \right)
    \left.
        f(x) = 3
  \right.
  \end{equation}

Do:
  gg=G

Expect tex:
  \[
    1+1
  \]

  \begin{align}
    2+2=4
  \end{align}

  \begin{equation}
    \left(
      f(x) = 3
    \right)
    \left.
    f(x) = 3
    \right.
  \end{equation}

Given tex (Indent tikz):
  \tikz \fill[green] rectangle (0.5,0.5); Something
      about something.

    \begin{tikzpicture}
       \draw [solid] let \p{I} = (0,0) in (1,1) -|
          (\x{I}-1cm,-1cm) node [yshift=-.25cm] {(i)};
       % Just some comment
       \end{tikzpicture}

       \begin{tikzpicture}
  % (i) center contact head
  \draw [solid] let \p{I} = (centerContactHead) in (centerContactHead) -|
    (\x{I}-.75cm,-2.5)
    node [yshift=-.25cm] {(i)};

  % (ii) outer conductor of the contact head
    \coordinate (outerContactHead) at (.8,-1.7);
    \draw [solid] let \p{O} = (outerContactHead)
      in (outerContactHead) -- (\x{O},-2.5)
        node [yshift=-.25cm] {(ii)};
       \end{tikzpicture}

Do:
  gg=G

Expect tex:
  \tikz \fill[green] rectangle (0.5,0.5); Something
  about something.

  \begin{tikzpicture}
    \draw [solid] let \p{I} = (0,0) in (1,1) -|
      (\x{I}-1cm,-1cm) node [yshift=-.25cm] {(i)};
    % Just some comment
  \end{tikzpicture}

  \begin{tikzpicture}
    % (i) center contact head
    \draw [solid] let \p{I} = (centerContactHead) in (centerContactHead) -|
      (\x{I}-.75cm,-2.5)
      node [yshift=-.25cm] {(i)};

    % (ii) outer conductor of the contact head
    \coordinate (outerContactHead) at (.8,-1.7);
    \draw [solid] let \p{O} = (outerContactHead)
      in (outerContactHead) -- (\x{O},-2.5)
      node [yshift=-.25cm] {(ii)};
  \end{tikzpicture}

Given tex (Indent verbatims):
    \begin{verbatim}
  #!/bin/bash
  echo "test"
      \end{verbatim}

    \begin{lstlisting}
  Indent
    should
      not affect verbatim environments!
      \end{lstlisting}

Do:
  gg=G

Expect tex:
  \begin{verbatim}
  #!/bin/bash
  echo "test"
  \end{verbatim}

  \begin{lstlisting}
  Indent
    should
      not affect verbatim environments!
  \end{lstlisting}