Atom

Atom (Wikipedia) is a multi-platform code editor that is itself based on Chromium. Turtles aside, Atom has a growing community and base of installable plugins and themes.

You can download and install via links from the main Atom site. If you're interested in checking out the code and contributing, see the developer page.

Workflow

A typical Atom workflow consists of the following.

1. Use Ctrl-Shift-R to find a symbol in the .tags file or Ctrl-P to find a file by name.
2. Switch between the header and the source using Alt-O(Ctrl-Opt-S on OSX).
3. While editing, you-complete-me package helps with C++ auto-completion and shows compile errors through lint package.
4. Press Ctrl-Shift-P and type format<Enter> to format the code.
5. Select the target to build by pressing F7 and typing, for example, base_unittests.
6. Rebuild again by pressing F9.

Atom packages

To setup this workflow, install Atom packages for Chrome development.

$ apm install build build-ninja clang-format \
    linter linter-cpplint linter-eslint switch-header-source you-complete-me

Autocomplete

Install C++ auto-completion engine.

$ git clone https://github.com/Valloric/ycmd.git ~/.ycmd
$ cd ~/.ycmd
$ ./build.py --clang-completer

On Mac, replace the last command above with the following.

$ ./build.py --clang-completer --system-libclang

JavaScript lint

Install JavaScript linter for Blink web tests.

$ npm install -g eslint eslint-config-google

Configure the JavaScript linter to use the Google style by default by replacing the contents of ~/.eslintrc with the following.

{
    "extends": "google",
    "env": {
      "browser": true
    }
}

Configuration

Configure Atom by replacing the contents of ~/.atom/config.cson with the following. Replace <path-of-your-home-dir> and <path-of-your-chrome-checkout> with the actual full paths of your home directory and chrome checkout. For example, these can be /Users/bob and /Users/bob/chrome/src.

"*":
  # Configure ninja builder.
  "build-ninja":
    ninjaOptions: [
      # The number of jobs to use when running ninja. Adjust to taste.
      "-j10"
    ]
    subdirs: [
      # The location of your build.ninja file.
      "out/gn"
    ]
  # Do not auto-format entire files on save.
  "clang-format":
    formatCOnSave: false
    formatCPlusPlusOnSave: false
  core:
    # Treat .h files as C++.
    customFileTypes:
      "source.cpp": [
        "h"
      ]
    # Don't send metrics if you're working on anything sensitive.
    disabledPackages: [
      "metrics"
      "exception-reporting"
    ]
  # Use spaces instead of tabs.
  editor:
    tabType: "soft"
  # Show lint errors only when you save the file.
  linter:
    lintOnFly: false
  # Configure JavaScript lint.
  "linter-eslint":
    eslintrcPath: "<path-of-your-home-dir>/.eslintrc"
    useGlobalEslint: true
  # Don't show ignored files in the project file browser.
  "tree-view":
    hideIgnoredNames: true
    hideVcsIgnoredFiles: true
  # Configure C++ autocomplete and lint.
  "you-complete-me":
    globalExtraConfig: "<path-of-your-chrome-checkout>/tools/vim/chromium.ycm_extra_conf.py"
    ycmdPath: "<path-of-your-home-dir>/.ycmd/"
# Java uses 4 space indents and 100 character lines.
".java.source":
  editor:
    preferredLineLength: 100
    tabLength: 4

Symbol lookup

Atom fuzzy file finder is slow to index all files in Chrome. If you're working on a project that frequently uses foo or bar in files names, you can create a small .tags file to efficiently search the symbols within these files. Be sure to use “Exuberant Ctags.”

$ git ls | egrep -i "foo|bar" | ctags -f .tags -L -

Don't create a ctags file for the full Chrome repository, as that would result in ~9GB tag file that will not be usable in Atom.