Language agnostic test toggle functionality for Emacs
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Toggle Test Build Status

Toggle Test allows you to quickly switch between test and test subject. This is a very useful tool to have when you are TDDing. Test Toggle is similar to test toggle functionality provided by IntelliJ and other JetBrains IDEs.


  • Test Toggle allows you quick navigate between test and source files, without having to remember file paths.
  • It creates the the test or source file you are trying to navigate to (along the entire directory hierarchy) if it does not already exist.
  • Sometimes there might be mutiple test files for a given source (Ex: Unit and Integration test). Test Toggle presents the user with choices whenever there is multiple matches and navigates to the chosen file (creating it of required).
  • Test Toggle is language/tech stack agnostic. So it can work with your Rails, Python, Clojure or any other project.
  • You can work with multiple such projects at the same time.


Install using ELPA:

Toogle test is available on Marmalade repo to install it, simple run M-x package-install toggle-test. You will to need to have marmalade repo included. The marmalade repo/instructions are here

Programmatic install:

You can also programmatically install toggle-test as follows (This can be embedded in the initialization file, if you need a reusable configuration):

(require 'package)
(add-to-list 'package-archives
         '("marmalade" . ""))
(if (not (package-installed-p 'toggle-test))
      (package-install 'toggle-test))

Manual Install:

To install test toggle, simply get the code from github or marmalade.

> git clone git://
> wget

And add the following lines to your initialization file.

(load-file "/path/to/toggle-test.el"); load toggle-test.el
(require 'toggle-test)

Recommended key binding

This is the recommended key binding for toggle test.

(global-set-key (kbd "C-c t") 'tgt-toggle)


Before you can start using Test Toggle you need to tell Test Toggle about your projects, you can do this by configuring the variable tgt-projects. The other optional configuration is tgt-open-in-new-window which controls where the files are opened. The rest of this section describes these 2 variables.


This configuration allows Toggle Test to understand the project structure and naming conventions. tgt-projects is a list where each item is a project configuration. Here is how you add to this list.

  (add-to-list 'tgt-projects '((:root-dir <root directory of project>)
                              (:src-dirs <list source folders relative to root>) 
                              (:test-dirs <list of test folders relative to root>)
                              (:test-prefixes <optional list of prefix strings that are added on source file names 
                                            to get test file names>)
                              (:test-suffixes <optional list of suffix strings without the file extension>))) 

Each project that you configure is an alist with :root-dir, :src-dirs, :test-dirs as mandatory and :test-prefixes, :test-suffixes as optional entries.

Assumptions: Test Toggle makes 2 assumptions about the all projects defined. These are not tricky assumptions. Most projects have folder organization and naming conventions that complement these assumptions

  • The test and source directory structure (tree hierarchy) is similar.

  • The test file name can be derived by adding some prefix or suffix to source file name.

    Ex: if the source file is src/controllers/ then the test is test/controllers/ Note that the :test-suffixes here is "_test"

Basic Example

For a python project follows coding convention of prefixing "test_" for test names and has a directory structure that look like this

|-- lib
|-- src
|   |--
|   `--
`-- tests

The configuration for this project would look look this

(add-to-list 'tgt-projects '((:root-dir "~/py-proj")
                              (:src-dirs "src") 
                              (:test-dirs "tests")
                              (:test-prefixes "test_")))

A more involved example

This is a project that has 3 modules a scala library, java library and a scala Play application.

|-- bar-lib
|   |-- src
|   |   `-- com
|   |       `-- bar
|   |           `--
|   `-- test
|       `-- com
|           `-- bar
|               `--
|-- foo-lib
|   |-- src
|   |   `-- Foo.scala
|   `-- test
|       `-- FooSpec.scala
|-- integration-specs
|   |-- Foo$Spec.scala
|   `-- controllers
|       `-- Application$Spec.scala
`-- play
    |-- app
    |   `-- controllers
    |       `-- Application.scala
    `-- test
        `-- controllers
            `-- ApplicationSpec.scala

Based on these observations about the project:

  • Scala tests have suffixes Spec, $Spec and java tests have Test suffix.
  • Integration tests for foo-lib and play app is in integration-specs.
  • bar-lib is an independent/self-contained module that has all tests/source source inside the bar-lib folder.
  • bar-lib has a completely different naming convention.

The best configuration for this project is,

(add-to-list 'tgt-projects '((:root-dir "~/polyglot-proj")
                              (:src-dirs "play/app" "foo-lib/src") 
                              (:test-dirs "play/test" "foo-lib/test" "integration-specs")
                              (:test-suffixes "Spec" "$Spec")))
(add-to-list 'tgt-projects '((:root-dir "~/polyglot-proj/bar-lib")
                              (:src-dirs "src") 
                              (:test-dirs "test")
                              (:test-suffixes "Test")))

Note that the potential candidates for foo-lib/src/Foo.scala are

  • play/test/FooSpec.scala
  • play/test/Foo$Spec.scala
  • foo-lib/test/FooSpec.scala
  • foo-lib/test/Foo$Spec.scala
  • integration-specs/test/FooSpec.scala
  • integration-specs/test/Foo$Spec.scala

The best match is foo-lib/test/FooSpec.scala as this file already exists.

If this file did not exist, then the user will be presented with all the options and the selected file is automatically created.

Adding new projects vs adding new src/test directories:

Note that in the configuration in the second example defines separate projects for bar-lib, while foo-lib is just extra entries in :src-dirs and :test-dirs. It is recommended that you define many smaller projects whenever possible. If a module is independent and contains all tests inside module directory then it is better to add it as a separate tgt-project. A separate project cannot be defined in case of foo-lib because integration-specs depends on both foo-lib and the Play application


This setting controls where the toggle file opens up. A non nil value opens the toggle file in a new window, so you can do a side-by-side edit of source and test files. A nil value replaces the current window content. The default value is t

  (setq tgt-open-in-new-window <'nil or t>)


  • Feel free to fork the repo, make changes and raise pull request once you are done. Toggle Test uses ert for unit/intergration tests. Keep them green and test your changes.
  • You can also contribute by reporting any bugs or feature requests in the issues section


GNU General Public License

Copyright (C) 2014 Raghunandan Rao