An environment for Ruby and JS developers in Darwin

Project maintained by New-Bamboo Originally based on the Midnight theme by mattgraham


Hermes is an environment for Ruby and JavaScript developers in Darwin using Tmux, Vim and iTerm 2 that focuses on speed and ease of use.

Hermes is opinionated where having an opinion is important, but does not prevent you from customizing your tools.

Hermes gives you a lot of things for free:

We feel that good documentation is a key part of using any new technology with lots of moving parts, so we will be improving Hermes’ documentation in the days and weeks to come.

Hermes screenshot
Hermes screenshot

Preliminary Thanks

Hermes combines plugins, settings, snippets, gists, and ideas from countless developers around the world. We would like to thank:


Warning! Hermes is still early in development, so just to be careful, we strongly encourage you to install it in a separate user account, not your main one. That said, we have tested it on our own user accounts, where it worked just fine.

You can check to see which files will be overwritten in manifests/dotfile_manifest, or follow this link to view it on Github.


Hermes relies on Homebrew and RVM to work properly. While Homebrew is a de facto standard developers using OS X, there are a good number of people that use RBenv, so support for that is in the pipeline. We are happy to look at any pull requests.

If these two tools are not available, the installer script will halt. Please refer to these tools’ excellent documentation for installation instructions.

Fork first!

As the very first step, you should fork the Hermes on Github since this will make it easier for you to customize your installation. After you’re done, you can run:

mkdir -p ~/.hermes
git clone<your_github_username>/Hermes.git ~/.hermes
cd ~/.hermes

This will perform the following actions:

You may also want to add Hermes’s repository as an upstream repository, so you can pull in the changes done on the main trunk whenever you need to.

Hermes installation
Hermes installation

What’s included in the installer

The installer will:

Hermes includes:

In addition, Hermes glues all components together so they play nicely with each other and the OS. Two examples of this integration are are Hermes’ support for the system clipboard in OS X and window/pane aware mouse integration.


Being a git-based project, you can update Hermes by simply pulling from the remote. If you forked the project, please remember to add the original repo as an upstream repository to make getting new project updates easier.

Documentation foreword

This document provides enough information to make you productive with Hermes, but it doesn’t cover the totality of what’s provided by all plugins, especially when it comes to Vim. Please refer to their original documentation for more details.

Hermes’ goal is to provide a solid structure for you to build on top of without having to deal with any intermediate configuration layers. For example, Vim’s entire configuration is managed canonically through the ~/.vimrc file and the ~/.vim folder. The only significant difference is that under the hood, those files are actually symlinks to your hermes folder.

Knowing how Hermes ties everything together is useful when it comes time to configure it.


A stock vim installation with a basic configuration can go a long way and can be really beneficial when it comes to editing files on a server.

There is however a very simple problem with the default Vim installation that OS X provides: it cannot access the system clipboard. That means if you copy anything from outside the editor, it’s not available in any of Vim’s registers. Worse yet, if you copy anything in Vim using its internal commands, it won’t be available to the rest of the system

To sort this out, Hermes installs Homebrew’s version of Vim, which is available through the MacVim package:

brew install macvim --override-system-vim

This has some additional benefits, like having support for Ruby in plugins.

Let’s now go with some defaults for a basic .vimrc file:

set nocompatible    "don't need Vi compatibility
set nobackup        "don't create backup files
set nowritebackup
set notimeout
set ttimeout
set ttimeoutlen=10
set noswapfile      "don't create swap files
set history=50      "keep a small history
set ruler           "always show position
set showcmd
set incsearch
set laststatus=2    "full status bar
set t_Co=256        "256 colors - requires a properly configured terminal emulator
syntax on           "turn syntax highlight on

filetype plugin indent on "let plugins manage indentation

" Send more characters for redraws
set ttyfast
" Enable mouse use in all modes
set mouse=a
set ttymouse=xterm2

" Fix backspace
set backspace=indent,eol,start

" Softtabs, 2 spaces
set tabstop=2
set shiftwidth=2
set expandtab

" Display extra whitespace at the end of the line
set list listchars=tab:»·,trail:·
" Clipboard fix for OsX
set clipboard=unnamed

" Numbers
set number
set numberwidth=2

set foldmethod=indent
set foldlevelstart=99

" Autocompletion options
set wildmode=list:longest,list:full
set complete=.,w,b"

These settings will allow you to efficiently edit any file whose type is supported by default, so Javascript and Ruby are already covered. The settings enable standard features like line numbering and syntax highlighting and also turn on features like mouse support and clipboard sharing that are useful in integrating Vim into iTerm and OS X.


Plugins are a powerful way to extend Vim’s capabilities. The implementation may change, but we feel you should be able to expect the following from a modern text editor:

Needless to say, a number of other text editors support these features. Vim, however, combines this with its extremely efficient modal editing approach.

Hermes provides a good number of plugins, aiming to strike a balance between features and speed. You can see the complete list under hermes/vim/bundle, but here are some highlights:

However, we encourage you to be wary of plugins for several reasons:

Vim’s approach to plugin management is a little counterintuitive: by default, Vim looks for additional scripts to load in ~/.vim, which has subfolders that determine when the configuration is loaded. For example, a script can be split across the plugin and the autoload directories, the former for the bulk, load-once functionality while the latter for anything that requires constant recalculation. This means that a manual installation may be spread across multiple directories, resulting in a structure that is difficult to maintain and update.

Enter Pathogen, a package manager that makes this process painless and that inverts the usual installation pattern, as it lets you organize plugins based on their name. With Pathogen, you can simply clone a repository into your ~/.vim folder and you’re done. This is the first stepping stone to efficient dotfile management through a git repository where you can add all your plugins as git submodules and update all of them with a single command.

Hermes uses git submodules extensively: since Pathogen allows us to keep each plugin in a separate folder, we can include all of our plugins as submodules in the hermes/vim/bundle folder. This makes it dead easy to add other plugins and keep them up-to-date:

cd ~/.hermes
git submodule add <github-url> hermes/vim/bundle/<plugin-name>

And you’re done! Updating plugins is similarly straightforward:

cd ~/.hermes
git submodule foreach git pull origin master

As in every other Github-based project, it’s advisable to fork a plugin if you need to make changes that go beyond simple configuration (which we usually add to ~/.hermes/vim/plugins.vim). In that case, you would need to remove the original submodule completely and add it back again using your fork as the source.

Pathogen loads the contents of ~/.vim/bundle by default. including itself. This is controlled by the first two lines in the ~/.vimrc file:

" loading pathogen at runtime as it's bundled
runtime bundle/vim-pathogen/autoload/pathogen.vim
call pathogen#infect()

Managing configuration

If you keep extending your .vimrc, it comes to a point where it’s simply too long, so it makes sense to split it into separate chunks of related configuration. Here’s an example from the bottom of a .vimrc:

source $HOME/.vim/autocommands.vim
source $HOME/.vim/plugins.vim
source $HOME/.vim/shortcuts.vim

Tip: Pressing gf in Vim’s normal mode will open the file under the cursor. This works with many other file types, including html documents.

Using gf
Using gf

We recommend that when working with new plugins, you add one at a time and pay close attention to their documentation. Plugins are often extremely configurable, as you can see in Hermes’ plugins.vim file. Taking the time to develop a feel for how each plugin works and configuring them for your specific needs can go a long way in optimising your workflow.

Documentation is usually available by typing :help <term-to-search>. However, Hermes has a custom shortcut you can use: by pressing <leader>h with the cursor over a word, you can search for that word in Vim’s help.

As an example, let’s look at the configuration Hermes supplies for Ctrl-p (in ~/.hermes/hermes/vim/plugins.vim):

set wildignore+=*/.hg/*,*/.svn/*,*/vendor/cache/*,*/public/system/*,*/tmp/*,*/log/*,*/.git/*,*/.jhw-cache/*,*/solr/data/*,*/node_modules/*,*/.DS_Store

The wildignore flag is not Ctrl-p specific, as it’s used by Vim or many autocompletion and expansion functions: the more unlikely targets we remove, the better Vim’s performance will be. Since Ctrl-p uses this pattern to determine a baseline for excluding files when creating its index, this simple addition will help keep it snappy.

Daily use cases

Here are a few examples of what you can do with Vim, bearing in mind that this is not meant to be an exhaustive guide. Instead, we will focus on frequent everyday tasks:

Shelling out

Having the shell at your disposal can speed up your workflow many times over, but to really take advantage of this it’s important to learn how to alternate between Vim and the command line.

Sometimes you just need to run a simple shell command, like creating a file or directory (i.e. folder). In that situation, press : in normal mode to enter the command mode. Then type ! to tell Vim to shell out and perform the command in the shell. So, if you want to create a sample directory, you can type:

:!mkdir sample

The command will be performed from within the current working directory, you can verify that with :pwd.

Shelling out
Shelling out

When you need to step out of the file you’re editing, perform a few tasks and then go back, your best option is to suspend Vim using the shell via ctrl-z and then resume it with by typing the command fg (foreground) when you’re done. This is a very straightforward approach and widely used in the Unix world. It works out of the box.


Alternatively, you can use a different window or pane with Tmux, as we shall explain later on.

As always, you can associate a shortcut for a shell command you want to run: a good example is creating a leader command to run the current file as a spec.

noremap <leader>s :!bundle exec rspec %<cr>

We use noremap to tell Vim to create a key map for normal mode, assign it to <leader>s and then specify the command, a simple bundle exec rspec where we include the current file as an argument and then press enter (carriage return).

Reading from a source into the current buffer

Another common use case is having to add content from a different source, like another file or a unix process.

Vim provides a very simple way to do this: the :r command.

If you have two files, a.txt and b.txt, you can open the first one and type: :r b.txt. This will add the contents of the second file in the current buffer (where you have opened a.txt).

You can combine the :r command with ! to shell out and get the contents from any command you wish. For example, you can use ls to list the contents of a directory to easily generate a manifest file. The full command would then be :r! ls.

Reading from the shell
Reading from the shell

Search and replace

Search and replace in Vim is a kind of regular expression usage. Vim expects you to provide a range and then a substitution command to perform.

So if you type:


It will search in the whole buffer % and substitute the first occurence of foo with bar. As you can imagine, you can pass flags to the command, like:


The g flag predictably tells Vim to perform a global search and replace, with multiple replacements, while the i (interactive) flag will allow you to confirm each substitution individually.

Search and replace on the whole file
Search and replace on the whole file

If you need to act on a specific number of lines, you have two options:

A common complaint by many people who switch from a graphical editor to Vim is that there’s no facility to execute a substitution command across files. Vim provides such tools by following a simple pattern:

This can be tricky: the argument list is the files of all currently open files and can be completely different from the buffer list. So if we wanted to perform a search and replace on all *.rb files in the current working directory we would do:

:args ./**.rb
:argdo %s/foo/bar/gi

Note the i flag, which is a lifesaver. The argdo command iterates over the argument list and performs the sspecified command (we still need the % to act on the whole file).

(If you use Vim’s tabs feature, see also tabdo for a way of doing operations across all your tabs.)

A different approach, and what we suggest, is not using Vim altogether but a shell based substitution.

First of all, you should make sure that you’re working with some sort of VCS, because what we’re about to do is not easily reversible.

We will be using Perl, as it’s fast, powerful and simple.

The aforementioned substitution can be achieved with:

perl -i.bak -pe's/foo/bar/g' ./**.rb

A VERY IMPORTANT NOTE: the above pattern is usually safe in the context of a Rails application, but if the pattern you used finds files inside .git, it will perform the substitution on them as well, potentially damaging your Git index. This can happen if your glob pattern is too loose or if you have submodules written in the same language.

However, the -i.bak argument does create a backup of the original file, so you’ll need to delete the .bak files after the substitution. If you really know what you’re doing, you can just use the -i by itself.

A safer approach, and one which makes also the search and replace command easier to manage, is to move into subfolders and perform it in different steps. This will also make it easier to check, test and manage.

Visual mode

You can access Vim’s “visual” model by pressing v (character selection) or V (line selection). When in visual mode, any movement will modify the selection. You can also click-drag a screen selection with the mouse, which will automatically put you in visual mode. Working in visual mode can be powerful, but in general it’s advisable not to use it too often, since the actions you take in visual mode are not recorded in a way that can easily be repeated, e.g. . in normal mode.

There are, however, situations where visual mode has a clear advantage. One technique, making use of a “visual block”, is great for doing the same thing to several lines at once.

Imagine this text in Vim:

a = 1
b = 2
c = 3

If we wanted to prepend the keyword var to every line shown above, we could to the following:

The var keyword should be prepended to each of the lines.

Visual block editing
Visual block editing

Note that this is not the only way to do this. For example, a macro or a normal mode command would have worked equally well. This latter approach is in fact usually more effective:

When a visual range is selected, pressing : opens the command prompt with the range prefilled. By typing :norm, Vim temporarily switches to normal mode, executing the subsequent command for each line in the visual range. We just used I to jump before the first letter in normal mode and type var.

Visual block normal mode
Visual block normal mode

This approach is good when the change we’re making doesn’t need to be repeated. In other situations, a macro is more effective.

Ctrl-p and fuzzy file search

Using Ctrl-p
Using Ctrl-p

Ctrl-p is a native Vim fuzzy finder. It can be used to search for files, buffers and tags with great configurability.

Hermes ships a ctrl-p configuration that uses the following defaults:

Ctrl-p can be easily invoked with… ctrl-p. As reported in its original readme, here are some commands you can use:

Note that any filesystem change (new or deleted files) requires a cache refresh, achievable by typing :CtrlPClearCache.

Working with Rails

Rails.vim supercharges Vim with functions, shortcuts and a general ‘rails-awareness’ factor that proves to be invaluable when editing a Rails project.

File navigation

Due to Rails’s conventional nature, any project uses the same folder structure, and all files the same naming conventions. Rails.vim leverages this factor and provides a series of commands to open specific files in a Rails project without manually navigating to the file and keeping the current working directory at the root of the Rails application.

These commands always follow the same pattern and are prefixed with R and are followed by the name of the file you want to open (stripped of the extension). Some examples are :Rmodel to open a model, :Rcontroller for a controller, and so on.

All commands support variations to tweak the behaviour: for example, RVcontroller will open the file in a vertically split pane. For a complete list, type :help rails-navigation.

Alternate and related files

When working on a certain feature, it’s common to switch between certain files: model to test, controller to related view and so on. Rails.vim provides shortcuts for this file jumps: every file has got two counterparts: alternate and related. As reported in the guide (:help rails-alternate):

Current file Alternate file Related file
model unit test schema definition
controller (in method) functional test template (view)
template (view) functional test controller (jump to method)
migration previous migration next migration
config/database.yml config/routes.rb config/environments/*.rb

So pressing :A will switch between a model and its test file, while :R on a controller index action will take us to the related index view. Again, this commands can be combined with modifiers to open the file in a new tab or split (:RV, :RE, etc.).

Overcharged gf

Other commands, like the afore-mentioned gf, get a proper boost, becoming shortcuts to jump to the right file when pressed over a certain keyword. As an example, let’s look at the following code:

class Post < ActiveRecord::Base

  belongs_to :author


Pressing gf on :author (any character) will open app/models/author.rb. Other examples are included in the relevant help section (help rails-gf).

Generators and Rake

You can use generators straight from Vim with RGenerate, with the nice side effects that the first generated file is automatically opened in the editor.

So, if you want to generate a new migration you can:

This leads us to the :Rake command: depending on the open file, it performs different functions. See :help rails-rake for details. Note that another plugin included with Hermes, vim-bundler, takes care of prepending bundle exec to all commands.

Partial refactoring

Another common operation is partial extraction, i.e. moving a certain portion of erb code into a separate partial file.

Let’s assume you have a file called app/views/users/show.html.erb with this content:

  <li><%= %></li>
  <li><%= %></li>

Using visual block mode (V), highlight the two <li> tags. Then type :Rextract user and press enter. This will create a file called app/views/users/_user.html.erb with the following content:

<li><%= %></li>
<li><%= %></li>

It will also update the show view by referencing that new partial:

  <%= render :partial => 'user' %>

Working with Tmux

Even if Vim by itself is indeed extremely powerful, it just shines when paired with Tmux. Tmux is a terminal multiplexer, a program to manage multiple shell instances in the scope of a single session (whether it’s local or SSH it doesn’t matter).

In other words, Tmux allows the creation of separate tabs (called windows) and splits (called panes), interaction between them and an external api for programmatic control.

The recurring question that people ask when hearing about Tmux for the first time is “Why should I use this instead of the native functionality provided by my terminal emulator?”. Here’s why:

Hermes includes an opinionated Tmux setup that solves a few compatibility issues with OsX, rebinds many shortcuts to an easier to remember layout and adds a few bells and whistles (like date, time and battery information in the status bar). Huge thanks to Thoughtbot for sharing most of the code that made it into this configuration.

Basic interaction

If you type tmux in your shell, you will start a new session. As we haven’t passed a name, the session will receive an incremental number to identify it. Tmux allows switching between different sessions, so ideally you would want a separate one for each project you’re working on.

At the bottom, you can see the list of windows on the left. This shows the current session windows, highlighting the current one. Windows also have an index, shown right on the left of the name.

The window behaves exactly like a “normal” terminal window, with just a couple of exceptions:

All tmux commands start with a prefix, set in this configuration to Ctrl-a: as a convention, this document will call this shortcut ‘prefix’, so prefix-c means ‘press Ctrl-a, then c’.

Using Tmux windows
Using Tmux windows

Here are some basic commands:

You can also change focus from one pane to another using the mouse, however that is usually slower than mastering keyboard shortcuts.

Using Tmux panes
Using Tmux panes

Scrolling, copy and paste

As expected, you can scroll inside a pane with your mouse, but Tmux supports complete mouseless interaction even for this kind of operation. This is possible by entering ‘copy mode’, where (similarly to Vim’s normal and visual modes, pressing keyboard keys doesn’t enter text but performs actions). Copy mode is identified by a status indicator in the top right corner of the pane (showing your cursor position in the current scroll buffer).

Copy mode can be entered by pressing prefix-esc, but it can be alternatively activated by:

Commands in copy mode are pretty much identical to Vim and that’s because Tmux handily supports a Vim compatibility mode, so that you don’t have to change your habits.

Using Tmux copy mode
Using Tmux copy mode

To see a list of all possible combinations, press prefix-: to enter command mode and type list-keys -t vi-copy. Note also that a good set of motions are supported, so you can type v4w to select 4 words from the current one.

Allow yourself some time to master copy mode, as it’s extremely powerful.

Note that if you use the mouse and perform a drag selection, text will be automatically copied into the clipboard upon releasing the left mouse button.

Tmux and Vim

Let’s assume you are working on Rails application. Thanks to Rails.vim, you can easily navigate the codebase, but running tests is still a bit painful. You can create some bindings as shown above, but reality is, it would be great if you could type a shortctut to run tests “somewhere” else without interrupting your flow.

Hermes ships a combination of plugins that let you control your test suite runs from Vim using a separate pane in a Tmux session, so that you can benefit from asynchronous test runs without leaving your editor. This is achieved thanks to different plugins (vimux, vimux-ruby-test, vimux-cucumber and vim-turbux). It may seem a complicated setup, but in reality it allows to work in a much more natural way.

As an example, navigate to a Rails application folder on your machine and start a Tmux session (if you’re not inside one already). Then, open vim.

Let’s assume you have a User model (really, any model is fine, this is just for example purposes), so open app/models/user.rb. We already know that :A lets us navigate to the corresponding spec file and back, but we can also do better:


This code is free to use under the terms of the MIT license.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.



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