diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..aaf3452
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,131 @@
+
+# Created by https://www.gitignore.io/api/macos,windows,linux,node
+
+### Linux ###
+*~
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+# .nfs files are created when an open file is removed but is still being accessed
+.nfs*
+
+### macOS ###
+*.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+### Node ###
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (http://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# Typescript v1 declaration files
+typings/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+
+
+### Windows ###
+# Windows thumbnail cache files
+Thumbs.db
+ehthumbs.db
+ehthumbs_vista.db
+
+# Folder config file
+Desktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
+
+# End of https://www.gitignore.io/api/macos,windows,linux,node
+
+yarn.lock
+package-lock.json
\ No newline at end of file
diff --git a/.npmrc b/.npmrc
new file mode 100644
index 0000000..43c97e7
--- /dev/null
+++ b/.npmrc
@@ -0,0 +1 @@
+package-lock=false
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..88d901f
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,30 @@
+language: node_js
+node_js:
+  - 9
+  - 8
+  - 6
+  - 4
+
+# Trigger a push build on master and greenkeeper branches + PRs build on every branches
+# Avoid double build on PRs (See https://github.com/travis-ci/travis-ci/issues/1147)
+branches:
+  only:
+    - master
+    - /^greenkeeper.*$/
+
+# Retry install on fail to avoid failing a build on network/disk/external errors
+install:
+  - travis_retry npm install
+
+script:
+  - npm run test
+
+jobs:
+  include:
+    - stage: release
+      node_js: node
+      os: linux
+      script: npm run test
+      after_success:
+        - npm run codecov
+        - npm run semantic-release
diff --git a/.yarnrc b/.yarnrc
new file mode 100644
index 0000000..acaaffd
--- /dev/null
+++ b/.yarnrc
@@ -0,0 +1 @@
+--install.no-lockfile true
diff --git a/README.md b/README.md
index 1ac0852..35a9b93 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,54 @@
 # env-ci
-Get environment variables exposed by CI services
+
+Get environment variables exposed by CI services.
+
+[![Travis](https://img.shields.io/travis/pvdlg/env-ci.svg)](https://travis-ci.org/pvdlg/env-ci)
+[![Codecov](https://img.shields.io/codecov/c/github/pvdlg/env-ci.svg)](https://codecov.io/gh/pvdlg/env-ci)
+[![Greenkeeper badge](https://badges.greenkeeper.io/pvdlg/env-ci.svg)](https://greenkeeper.io/)
+
+Adapted from [codecov-node](https://github.com/codecov/codecov-node/blob/master/lib/detect.js).
+
+## Install
+
+```bash
+$ npm install --save env-ci
+```
+
+## Usage
+
+```js
+const {isCi, service, commit, build, branch, job, pr, isPr, slug, root} = require('env-ci');
+```
+
+## Variables
+
+| Variable  | Description                                                                       |
+|-----------|-----------------------------------------------------------------------------------|
+| `isCi`    | `true` is running on a CI, `false` otherwise                                      |
+| `service` | CI service name                                                                   |
+| `commit`  | Commit sha that triggered the CI build                                            |
+| `build`   | CI service build number                                                           |
+| `branch`  | Git branch being built or targeted by a pull request                              |
+| `job`     | CI service job number                                                             |
+| `pr`      | Pull Request number                                                               |
+| `isPr`    | `true` is the build has been triggered by a Pull Request, `false` otherwise       |
+| `slug`    | The slug (in form: owner_name/repo_name) of the repository currently being built. |
+| `root`    | The path to the directory where the repository is being built                     |
+
+## Supported CI
+
+| Service                                                     | `isCi` | `service` | `commit` | `build` | `branch` | `job` | `pr` | `isPr` | `slug` | `root` |
+|-------------------------------------------------------------|:------:|:---------:|:--------:|:-------:|:--------:|:-----:|:----:|:------:|:------:|:------:|
+| [AppVeyor](https://www.appveyor.com)                        | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ✅   |  ✅   |   ✅    |   ✅    |   ✅    |
+| [Buildkite](https://buildkite.com)                          | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ❌   |  ✅   |   ✅    |   ✅    |   ✅    |
+| [Circleci](https://circleci.com)                            | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ✅   |  ✅   |   ✅    |   ✅    |   ❌    |
+| [Codeship](https://codeship.com)                            | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ❌   |  ❌   |   ❌    |   ✅    |   ❌    |
+| [Drone](http://try.drone.io)                                | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ✅   |  ✅   |   ✅    |   ✅    |   ❌    |
+| [Gitlab CI](https://about.gitlab.com/features/gitlab-ci-cd) | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ✅   |  ❌   |   ❌    |   ✅    |   ✅    |
+| [Jenkins](https://jenkins-ci.org)                           | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ❌   |  ❌   |   ❌    |   ✅    |   ✅    |
+| [Semaphore](https://semaphoreci.com)                        | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ✅   |  ✅   |   ✅    |   ✅    |   ✅    |
+| [Shippable](https://www.shippable.com)                      | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ✅   |  ✅   |   ✅    |   ✅    |   ✅    |
+| [Travis](https://travis-ci.org/)                            | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ✅   |  ✅   |   ✅    |   ✅    |   ✅    |
+| [Wercker](http://www.wercker.com/)                          | ✅      |     ✅     |    ✅     |    ✅    |    ✅     |   ❌   |  ❌   |   ❌    |   ✅    |   ✅    |
+
+If none of the above CI services is detected, `commit` and `branch` are determined based on the local Git repository, and `isCi` is determined based on  the `CI` environment variable.
diff --git a/index.js b/index.js
new file mode 100644
index 0000000..d9e9281
--- /dev/null
+++ b/index.js
@@ -0,0 +1,26 @@
+'use strict';
+
+const git = require('./lib/git');
+
+const services = {
+  travis: require('./lib/travis'),
+  circle: require('./lib/circle'),
+  appveyor: require('./lib/appveyor'),
+  wercker: require('./lib/wercker'),
+  codeship: require('./lib/codeship'),
+  jenkins: require('./lib/jenkins'),
+  semaphore: require('./lib/semaphore'),
+  shippable: require('./lib/shippable'),
+  drone: require('./lib/drone'),
+  buildkite: require('./lib/buildkite'),
+  gitlab: require('./lib/gitlab'),
+};
+
+module.exports = () => {
+  for (const name of Object.keys(services)) {
+    if (services[name].detect()) {
+      return Object.assign({isCi: true}, services[name].configuration());
+    }
+  }
+  return Object.assign({isCi: Boolean(process.env.CI)}, git.configuration());
+};
diff --git a/lib/appveyor.js b/lib/appveyor.js
new file mode 100644
index 0000000..85d0a93
--- /dev/null
+++ b/lib/appveyor.js
@@ -0,0 +1,20 @@
+// https://www.appveyor.com/docs/environment-variables/
+
+module.exports = {
+  detect() {
+    return Boolean(process.env.APPVEYOR);
+  },
+  configuration() {
+    return {
+      service: 'appveyor',
+      commit: process.env.APPVEYOR_REPO_COMMIT,
+      build: process.env.APPVEYOR_BUILD_NUMBER,
+      branch: process.env.APPVEYOR_REPO_BRANCH,
+      job: process.env.APPVEYOR_JOB_NUMBER,
+      pr: process.env.APPVEYOR_PULL_REQUEST_NUMBER,
+      isPr: Boolean(process.env.APPVEYOR_PULL_REQUEST_NUMBER),
+      slug: process.env.APPVEYOR_REPO_NAME,
+      root: process.env.APPVEYOR_BUILD_FOLDER,
+    };
+  },
+};
diff --git a/lib/buildkite.js b/lib/buildkite.js
new file mode 100644
index 0000000..116541c
--- /dev/null
+++ b/lib/buildkite.js
@@ -0,0 +1,19 @@
+// https://buildkite.com/docs/builds/environment-variables
+
+module.exports = {
+  detect() {
+    return Boolean(process.env.BUILDKITE);
+  },
+  configuration() {
+    return {
+      service: 'buildkite',
+      build: process.env.BUILDKITE_BUILD_NUMBER,
+      commit: process.env.BUILDKITE_COMMIT,
+      branch: process.env.BUILDKITE_BRANCH,
+      slug: `${process.env.BUILDKITE_ORGANIZATION_SLUG}/${process.env.BUILDKITE_PROJECT_SLUG}`,
+      pr: process.env.BUILDKITE_PULL_REQUEST === 'false' ? undefined : process.env.BUILDKITE_PULL_REQUEST,
+      isPr: process.env.BUILDKITE_PULL_REQUEST && process.env.BUILDKITE_PULL_REQUEST !== 'false',
+      root: process.env.BUILDKITE_BUILD_CHECKOUT_PATH,
+    };
+  },
+};
diff --git a/lib/circle.js b/lib/circle.js
new file mode 100644
index 0000000..88e435f
--- /dev/null
+++ b/lib/circle.js
@@ -0,0 +1,19 @@
+// https://circleci.com/docs/1.0/environment-variables/
+
+module.exports = {
+  detect() {
+    return Boolean(process.env.CIRCLECI);
+  },
+  configuration() {
+    return {
+      service: 'circleci',
+      build: `${process.env.CIRCLE_BUILD_NUM}.${process.env.CIRCLE_NODE_INDEX}`,
+      job: `${process.env.CIRCLE_BUILD_NUM}.${process.env.CIRCLE_NODE_INDEX}`,
+      commit: process.env.CIRCLE_SHA1,
+      branch: process.env.CIRCLE_BRANCH,
+      pr: process.env.CI_PULL_REQUEST ? process.env.CI_PULL_REQUEST.split('/').pop() : undefined,
+      isPr: Boolean(process.env.CI_PULL_REQUEST),
+      slug: `${process.env.CIRCLE_PROJECT_USERNAME}/${process.env.CIRCLE_PROJECT_REPONAME}`,
+    };
+  },
+};
diff --git a/lib/codeship.js b/lib/codeship.js
new file mode 100644
index 0000000..8867c6c
--- /dev/null
+++ b/lib/codeship.js
@@ -0,0 +1,16 @@
+// https://documentation.codeship.com/basic/builds-and-configuration/set-environment-variables/
+
+module.exports = {
+  detect() {
+    return process.env.CI_NAME && process.env.CI_NAME === 'codeship';
+  },
+  configuration() {
+    return {
+      service: 'codeship',
+      build: process.env.CI_BUILD_NUMBER,
+      commit: process.env.CI_COMMIT_ID,
+      branch: process.env.CI_BRANCH,
+      slug: process.env.CI_REPO_NAME,
+    };
+  },
+};
diff --git a/lib/drone.js b/lib/drone.js
new file mode 100644
index 0000000..f8e1098
--- /dev/null
+++ b/lib/drone.js
@@ -0,0 +1,19 @@
+// http://readme.drone.io/0.5/usage/environment-reference/
+
+module.exports = {
+  detect() {
+    return Boolean(process.env.DRONE);
+  },
+  configuration() {
+    return {
+      service: 'drone',
+      commit: process.env.DRONE_COMMIT_SHA,
+      build: process.env.DRONE_BUILD_NUMBER,
+      branch: process.env.DRONE_BRANCH,
+      job: process.env.DRONE_JOB_NUMBER,
+      pr: process.env.DRONE_PULL_REQUEST,
+      isPr: process.env.DRONE_BUILD_EVENT === 'pull_request',
+      slug: `${process.env.DRONE_REPO_OWNER}/${process.env.DRONE_REPO_NAME}`,
+    };
+  },
+};
diff --git a/lib/git.js b/lib/git.js
new file mode 100644
index 0000000..40ca59e
--- /dev/null
+++ b/lib/git.js
@@ -0,0 +1,26 @@
+const execa = require('execa');
+
+function configuration() {
+  return {
+    commit: head(),
+    branch: branch(),
+  };
+}
+
+function head() {
+  try {
+    return execa.sync('git', ['rev-parse', 'HEAD']).stdout;
+  } catch (err) {
+    return undefined;
+  }
+}
+
+function branch() {
+  try {
+    return execa.sync('git', ['rev-parse', '--abbrev-ref', 'HEAD']).stdout;
+  } catch (err) {
+    return undefined;
+  }
+}
+
+module.exports = {configuration, head, branch};
diff --git a/lib/gitlab.js b/lib/gitlab.js
new file mode 100644
index 0000000..0bb0b45
--- /dev/null
+++ b/lib/gitlab.js
@@ -0,0 +1,23 @@
+// https://docs.gitlab.com/ce/ci/variables/README.html
+
+module.exports = {
+  detect() {
+    return Boolean(process.env.GITLAB_CI);
+  },
+  configuration() {
+    return {
+      service: 'gitlab',
+      commit: process.env.CI_COMMIT_SHA,
+      build: process.env.CI_JOB_NAME,
+      job: process.env.CI_JOB_STAGE,
+      branch: process.env.CI_COMMIT_REF_NAME,
+      slug: process.env.CI_REPOSITORY_URL
+        ? process.env.CI_REPOSITORY_URL.split('/')
+            .slice(3, 5)
+            .join('/')
+            .replace('.git', '')
+        : undefined,
+      root: process.env.CI_PROJECT_DIR,
+    };
+  },
+};
diff --git a/lib/jenkins.js b/lib/jenkins.js
new file mode 100644
index 0000000..84dda50
--- /dev/null
+++ b/lib/jenkins.js
@@ -0,0 +1,20 @@
+const git = require('../lib/git');
+
+// https://wiki.jenkins.io/display/JENKINS/Building+a+software+project
+
+module.exports = {
+  detect() {
+    return Boolean(process.env.JENKINS_URL);
+  },
+  configuration() {
+    return {
+      service: 'jenkins',
+      commit: process.env.ghprbActualCommit || process.env.GIT_COMMIT || git.head(),
+      branch: process.env.ghprbSourceBranch || process.env.GIT_BRANCH || process.env.BRANCH_NAME,
+      build: process.env.BUILD_NUMBER,
+      root: process.env.WORKSPACE,
+      pr: process.env.ghprbPullId || process.env.CHANGE_ID,
+      isPr: Boolean(process.env.ghprbPullId || process.env.CHANGE_ID),
+    };
+  },
+};
diff --git a/lib/semaphore.js b/lib/semaphore.js
new file mode 100644
index 0000000..4fbd29d
--- /dev/null
+++ b/lib/semaphore.js
@@ -0,0 +1,21 @@
+const git = require('../lib/git');
+
+// https://semaphoreci.com/docs/available-environment-variables.html
+
+module.exports = {
+  detect() {
+    return Boolean(process.env.SEMAPHORE);
+  },
+  configuration() {
+    return {
+      service: 'semaphore',
+      commit: git.head(),
+      build: process.env.SEMAPHORE_BUILD_NUMBER,
+      branch: process.env.BRANCH_NAME,
+      pr: process.env.PULL_REQUEST_NUMBER,
+      isPr: Boolean(process.env.PULL_REQUEST_NUMBER),
+      slug: process.env.SEMAPHORE_REPO_SLUG,
+      root: process.env.SEMAPHORE_PROJECT_DIR,
+    };
+  },
+};
diff --git a/lib/shippable.js b/lib/shippable.js
new file mode 100644
index 0000000..300c6da
--- /dev/null
+++ b/lib/shippable.js
@@ -0,0 +1,20 @@
+// http://docs.shippable.com/ci/env-vars/#stdEnv
+
+module.exports = {
+  detect() {
+    return Boolean(process.env.SHIPPABLE);
+  },
+  configuration() {
+    return {
+      service: 'shippable',
+      commit: process.env.COMMIT,
+      build: process.env.BUILD_NUMBER,
+      branch: process.env.BASE_BRANCH || process.env.BRANCH,
+      job: process.env.JOB_NUMBER,
+      pr: process.env.PULL_REQUEST === 'false' ? undefined : process.env.PULL_REQUEST,
+      isPr: process.env.IS_PULL_REQUEST && process.env.IS_PULL_REQUEST === 'true',
+      slug: process.env.SHIPPABLE_REPO_SLUG,
+      root: process.env.SHIPPABLE_BUILD_DIR,
+    };
+  },
+};
diff --git a/lib/travis.js b/lib/travis.js
new file mode 100644
index 0000000..9f66fa2
--- /dev/null
+++ b/lib/travis.js
@@ -0,0 +1,20 @@
+// https://docs.travis-ci.com/user/environment-variables/
+
+module.exports = {
+  detect() {
+    return Boolean(process.env.TRAVIS);
+  },
+  configuration() {
+    return {
+      service: 'travis',
+      commit: process.env.TRAVIS_COMMIT,
+      build: process.env.TRAVIS_BUILD_NUMBER,
+      branch: process.env.TRAVIS_BRANCH,
+      job: process.env.TRAVIS_JOB_NUMBER,
+      pr: process.env.TRAVIS_PULL_REQUEST === 'false' ? undefined : process.env.TRAVIS_PULL_REQUEST,
+      isPr: process.env.TRAVIS_PULL_REQUEST && process.env.TRAVIS_PULL_REQUEST !== 'false',
+      slug: process.env.TRAVIS_REPO_SLUG,
+      root: process.env.TRAVIS_BUILD_DIR,
+    };
+  },
+};
diff --git a/lib/wercker.js b/lib/wercker.js
new file mode 100644
index 0000000..17bc983
--- /dev/null
+++ b/lib/wercker.js
@@ -0,0 +1,17 @@
+// http://devcenter.wercker.com/docs/environment-variables/available-env-vars#hs_cos_wrapper_name
+
+module.exports = {
+  detect() {
+    return Boolean(process.env.WERCKER_MAIN_PIPELINE_STARTED);
+  },
+  configuration() {
+    return {
+      service: 'wercker',
+      commit: process.env.WERCKER_GIT_COMMIT,
+      build: process.env.WERCKER_MAIN_PIPELINE_STARTED,
+      branch: process.env.WERCKER_GIT_BRANCH,
+      slug: `${process.env.WERCKER_GIT_OWNER}/${process.env.WERCKER_GIT_REPOSITORY}`,
+      root: process.env.WERCKER_ROOT,
+    };
+  },
+};
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..c71e20b
--- /dev/null
+++ b/package.json
@@ -0,0 +1,91 @@
+{
+  "name": "env-ci",
+  "description": "Get environment variables exposed by CI services",
+  "version": "0.0.0-development",
+  "author": "Pierre Vanduynslager (https://github.com/pvdlg)",
+  "bugs": {
+    "url": "https://github.com/pvdlg/github-parser/issues"
+  },
+  "dependencies": {
+    "execa": "^0.8.0"
+  },
+  "devDependencies": {
+    "ava": "^0.23.0",
+    "codecov": "^3.0.0",
+    "eslint-config-prettier": "^2.3.0",
+    "eslint-plugin-prettier": "^2.3.0",
+    "nyc": "^11.1.0",
+    "prettier": "~1.8.2",
+    "semantic-release": "^11.0.0",
+    "tempy": "^0.2.1",
+    "xo": "^0.18.2"
+  },
+  "engines": {
+    "node": ">=4"
+  },
+  "files": [
+    "lib",
+    "index.js"
+  ],
+  "homepage": "https://github.com/pvdlg/env-ci#readme",
+  "keywords": [
+    "appveyor",
+    "buildkite",
+    "ci",
+    "circle",
+    "codeship",
+    "drone",
+    "environment",
+    "gitlab",
+    "jenkins",
+    "semaphore",
+    "shippable",
+    "travis",
+    "variable",
+    "wercker"
+  ],
+  "license": "MIT",
+  "main": "index.js",
+  "nyc": {
+    "include": [
+      "lib/**/*.js",
+      "index.js"
+    ],
+    "reporter": [
+      "json",
+      "text",
+      "html"
+    ],
+    "all": true
+  },
+  "prettier": {
+    "printWidth": 120,
+    "singleQuote": true,
+    "bracketSpacing": false,
+    "trailingComma": "es5"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/pvdlg/env-ci.git"
+  },
+  "scripts": {
+    "codecov": "codecov -f coverage/coverage-final.json",
+    "lint": "xo",
+    "semantic-release": "semantic-release",
+    "test": "xo && nyc ava -v"
+  },
+  "xo": {
+    "extends": [
+      "prettier"
+    ],
+    "plugins": [
+      "prettier"
+    ],
+    "rules": {
+      "prettier/prettier": 2
+    }
+  }
+}
diff --git a/test/appveyor.test.js b/test/appveyor.test.js
new file mode 100644
index 0000000..2672e3a
--- /dev/null
+++ b/test/appveyor.test.js
@@ -0,0 +1,48 @@
+import test from 'ava';
+import appveyor from '../lib/appveyor';
+
+test('Push', t => {
+  process.env.APPVEYOR = 'true';
+  process.env.APPVEYOR_JOB_NUMBER = '1234';
+  process.env.APPVEYOR_REPO_COMMIT = '5678';
+  process.env.APPVEYOR_BUILD_NUMBER = '91011';
+  process.env.APPVEYOR_REPO_BRANCH = 'master';
+  process.env.APPVEYOR_REPO_NAME = 'owner/repo';
+  process.env.APPVEYOR_BUILD_FOLDER = '/';
+  delete process.env.APPVEYOR_PULL_REQUEST_NUMBER;
+
+  t.deepEqual(appveyor.configuration(), {
+    service: 'appveyor',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    job: '1234',
+    pr: undefined,
+    isPr: false,
+    slug: 'owner/repo',
+  });
+});
+
+test('PR', t => {
+  process.env.APPVEYOR = 'true';
+  process.env.APPVEYOR_JOB_NUMBER = '1234';
+  process.env.APPVEYOR_REPO_COMMIT = '5678';
+  process.env.APPVEYOR_BUILD_NUMBER = '91011';
+  process.env.APPVEYOR_REPO_NAME = 'owner/repo';
+  process.env.APPVEYOR_BUILD_FOLDER = '/';
+  process.env.APPVEYOR_PULL_REQUEST_NUMBER = '10';
+  process.env.APPVEYOR_REPO_BRANCH = 'master';
+
+  t.deepEqual(appveyor.configuration(), {
+    service: 'appveyor',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    job: '1234',
+    pr: '10',
+    isPr: true,
+    slug: 'owner/repo',
+  });
+});
diff --git a/test/buildkite.test.js b/test/buildkite.test.js
new file mode 100644
index 0000000..634e19c
--- /dev/null
+++ b/test/buildkite.test.js
@@ -0,0 +1,46 @@
+import test from 'ava';
+import buildkite from '../lib/buildkite';
+
+test('Push', t => {
+  process.env.BUILDKITE = 'true';
+  process.env.BUILDKITE_COMMIT = '5678';
+  process.env.BUILDKITE_BUILD_NUMBER = '91011';
+  process.env.BUILDKITE_BRANCH = 'master';
+  process.env.BUILDKITE_PULL_REQUEST = 'false';
+  process.env.BUILDKITE_BUILD_CHECKOUT_PATH = '/';
+  process.env.BUILDKITE_ORGANIZATION_SLUG = 'owner';
+  process.env.BUILDKITE_PROJECT_SLUG = 'repo';
+
+  t.deepEqual(buildkite.configuration(), {
+    service: 'buildkite',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    pr: undefined,
+    isPr: false,
+    slug: 'owner/repo',
+  });
+});
+
+test('PR', t => {
+  process.env.BUILDKITE = 'true';
+  process.env.BUILDKITE_COMMIT = '5678';
+  process.env.BUILDKITE_BUILD_NUMBER = '91011';
+  process.env.BUILDKITE_BRANCH = 'master';
+  process.env.BUILDKITE_PULL_REQUEST = '10';
+  process.env.BUILDKITE_BUILD_CHECKOUT_PATH = '/';
+  process.env.BUILDKITE_ORGANIZATION_SLUG = 'owner';
+  process.env.BUILDKITE_PROJECT_SLUG = 'repo';
+
+  t.deepEqual(buildkite.configuration(), {
+    service: 'buildkite',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    pr: '10',
+    isPr: true,
+    slug: 'owner/repo',
+  });
+});
diff --git a/test/circle.test.js b/test/circle.test.js
new file mode 100644
index 0000000..7400ed0
--- /dev/null
+++ b/test/circle.test.js
@@ -0,0 +1,46 @@
+import test from 'ava';
+import circle from '../lib/circle';
+
+test('Push', t => {
+  process.env.CIRCLECI = 'true';
+  process.env.CIRCLE_BUILD_NUM = '1234';
+  process.env.CIRCLE_SHA1 = '5678';
+  process.env.CIRCLE_BRANCH = 'master';
+  process.env.CIRCLE_NODE_INDEX = '1';
+  process.env.CIRCLE_PROJECT_USERNAME = 'owner';
+  process.env.CIRCLE_PROJECT_REPONAME = 'repo';
+  delete process.env.CI_PULL_REQUEST;
+
+  t.deepEqual(circle.configuration(), {
+    service: 'circleci',
+    commit: '5678',
+    build: '1234.1',
+    job: '1234.1',
+    branch: 'master',
+    pr: undefined,
+    isPr: false,
+    slug: 'owner/repo',
+  });
+});
+
+test('PR', t => {
+  process.env.CIRCLECI = 'true';
+  process.env.CIRCLE_BUILD_NUM = '1234';
+  process.env.CIRCLE_SHA1 = '5678';
+  process.env.CIRCLE_BRANCH = 'pr_branch';
+  process.env.CIRCLE_NODE_INDEX = '1';
+  process.env.CIRCLE_PROJECT_USERNAME = 'owner';
+  process.env.CIRCLE_PROJECT_REPONAME = 'repo';
+  process.env.CI_PULL_REQUEST = 'uri/pr/10';
+
+  t.deepEqual(circle.configuration(), {
+    service: 'circleci',
+    commit: '5678',
+    build: '1234.1',
+    job: '1234.1',
+    branch: 'pr_branch',
+    pr: '10',
+    isPr: true,
+    slug: 'owner/repo',
+  });
+});
diff --git a/test/codeship.test.js b/test/codeship.test.js
new file mode 100644
index 0000000..211d715
--- /dev/null
+++ b/test/codeship.test.js
@@ -0,0 +1,18 @@
+import test from 'ava';
+import codeship from '../lib/codeship';
+
+test('Push', t => {
+  process.env.CI_NAME = 'codeship';
+  process.env.CI_BUILD_NUMBER = '91011';
+  process.env.CI_COMMIT_ID = '5678';
+  process.env.CI_BRANCH = 'master';
+  process.env.CI_REPO_NAME = 'owner/repo';
+
+  t.deepEqual(codeship.configuration(), {
+    service: 'codeship',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    slug: 'owner/repo',
+  });
+});
diff --git a/test/drone.test.js b/test/drone.test.js
new file mode 100644
index 0000000..750ce0d
--- /dev/null
+++ b/test/drone.test.js
@@ -0,0 +1,48 @@
+import test from 'ava';
+import drone from '../lib/drone';
+
+test('Push', t => {
+  process.env.DRONE = 'true';
+  process.env.DRONE_JOB_NUMBER = '1234';
+  process.env.DRONE_COMMIT_SHA = '5678';
+  process.env.DRONE_BUILD_NUMBER = '91011';
+  process.env.DRONE_BRANCH = 'master';
+  process.env.DRONE_REPO_OWNER = 'owner';
+  process.env.DRONE_REPO_NAME = 'repo';
+  delete process.env.DRONE_PULL_REQUEST;
+  delete process.env.DRONE_BUILD_EVENT;
+
+  t.deepEqual(drone.configuration(), {
+    service: 'drone',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    job: '1234',
+    pr: undefined,
+    isPr: false,
+    slug: 'owner/repo',
+  });
+});
+
+test('PR', t => {
+  process.env.DRONE = 'true';
+  process.env.DRONE_JOB_NUMBER = '1234';
+  process.env.DRONE_COMMIT_SHA = '5678';
+  process.env.DRONE_BUILD_NUMBER = '91011';
+  process.env.DRONE_BRANCH = 'master';
+  process.env.DRONE_PULL_REQUEST = '10';
+  process.env.DRONE_BUILD_EVENT = 'pull_request';
+  process.env.DRONE_REPO_OWNER = 'owner';
+  process.env.DRONE_REPO_NAME = 'repo';
+
+  t.deepEqual(drone.configuration(), {
+    service: 'drone',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    job: '1234',
+    pr: '10',
+    isPr: true,
+    slug: 'owner/repo',
+  });
+});
diff --git a/test/git.test.js b/test/git.test.js
new file mode 100644
index 0000000..f4edeff
--- /dev/null
+++ b/test/git.test.js
@@ -0,0 +1,21 @@
+import test from 'ava';
+import git from '../lib/git';
+import {gitRepo, gitCommit} from './helpers/git-utils';
+
+// Save the current working diretory
+const cwd = process.cwd();
+
+test.beforeEach(async () => {
+  await gitRepo('master');
+});
+
+test.afterEach.always(() => {
+  // Restore the current working directory
+  process.chdir(cwd);
+});
+
+test.serial('Git repository', async t => {
+  const commit = await gitCommit();
+
+  t.deepEqual(git.configuration(), {commit, branch: 'master'});
+});
diff --git a/test/gitlab.test.js b/test/gitlab.test.js
new file mode 100644
index 0000000..25de590
--- /dev/null
+++ b/test/gitlab.test.js
@@ -0,0 +1,42 @@
+import test from 'ava';
+import gitlab from '../lib/gitlab';
+
+test('Push', t => {
+  process.env.GITLAB_CI = 'true';
+  process.env.CI_COMMIT_SHA = '5678';
+  process.env.CI_JOB_NAME = '91011';
+  process.env.CI_JOB_STAGE = '1234';
+  process.env.CI_COMMIT_REF_NAME = 'master';
+  process.env.CI_REPOSITORY_URL = 'https://gitlab.com/owner/repo.git';
+  process.env.CI_PROJECT_DIR = '/';
+
+  t.deepEqual(gitlab.configuration(), {
+    service: 'gitlab',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    job: '1234',
+    slug: 'owner/repo',
+  });
+});
+
+test('Push (no repo url)', t => {
+  process.env.GITLAB_CI = 'true';
+  process.env.CI_COMMIT_SHA = '5678';
+  process.env.CI_JOB_NAME = '91011';
+  process.env.CI_JOB_STAGE = '1234';
+  process.env.CI_COMMIT_REF_NAME = 'master';
+  process.env.CI_PROJECT_DIR = '/';
+  delete process.env.CI_REPOSITORY_URL;
+
+  t.deepEqual(gitlab.configuration(), {
+    service: 'gitlab',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    job: '1234',
+    slug: undefined,
+  });
+});
diff --git a/test/helpers/git-utils.js b/test/helpers/git-utils.js
new file mode 100644
index 0000000..8c8c626
--- /dev/null
+++ b/test/helpers/git-utils.js
@@ -0,0 +1,30 @@
+import tempy from 'tempy';
+import execa from 'execa';
+
+/**
+ * Create a git repository and change the current working directory to the repository root.
+ *
+ * @method gitRepo
+ * @param {String} [branch='master'] The branch to initialize.
+ * @return {String} The path of the repository otherwise.
+ */
+export async function gitRepo(branch = 'master') {
+  const dir = tempy.directory();
+
+  process.chdir(dir);
+  await execa('git', ['init']);
+  await execa('git', ['checkout', '-b', branch]);
+  return dir;
+}
+
+/**
+ * Create commit on the current git repository.
+ *
+ * @param {String} message commit message.
+ *
+ * @returns {String} The created commit sha.
+ */
+export async function gitCommit(message = 'Test commit message') {
+  await execa('git', ['commit', '-m', message, '--allow-empty', '--no-gpg-sign']);
+  return execa.stdout('git', ['rev-parse', 'HEAD']);
+}
diff --git a/test/index.test.js b/test/index.test.js
new file mode 100644
index 0000000..5e0485d
--- /dev/null
+++ b/test/index.test.js
@@ -0,0 +1,146 @@
+import test from 'ava';
+import tempy from 'tempy';
+import m from '..';
+import {gitRepo, gitCommit} from './helpers/git-utils';
+
+// Save the current working diretory
+const cwd = process.cwd();
+
+test.beforeEach(() => {
+  delete process.env.CI;
+  delete process.env.APPVEYOR;
+  delete process.env.BUILDKITE;
+  delete process.env.CIRCLECI;
+  delete process.env.CI_NAME;
+  delete process.env.DRONE;
+  delete process.env.GITLAB_CI;
+  delete process.env.JENKINS_URL;
+  delete process.env.SEMAPHORE;
+  delete process.env.SHIPPABLE;
+  delete process.env.TRAVIS;
+  delete process.env.WERCKER_MAIN_PIPELINE_STARTED;
+});
+
+test.afterEach.always(() => {
+  // Restore the current working directory
+  process.chdir(cwd);
+});
+
+test.serial('Appveyor', t => {
+  process.env.APPVEYOR = 'true';
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'appveyor');
+});
+
+test.serial('Buildkite', t => {
+  process.env.BUILDKITE = 'true';
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'buildkite');
+});
+
+test.serial('Circle CI', t => {
+  process.env.CIRCLECI = 'true';
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'circleci');
+});
+
+test.serial('Codeship', t => {
+  process.env.CI_NAME = 'codeship';
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'codeship');
+});
+
+test.serial('Drone', t => {
+  process.env.DRONE = 'true';
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'drone');
+});
+
+test.serial('Gitlab', t => {
+  process.env.GITLAB_CI = 'true';
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'gitlab');
+});
+
+test.serial('Jenkins', async t => {
+  process.env.JENKINS_URL = 'http://jenkins.jenkins.example/';
+  await gitRepo();
+  await gitCommit();
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'jenkins');
+});
+
+test.serial('Semaphore', async t => {
+  process.env.SEMAPHORE = 'true';
+  await gitRepo();
+  await gitCommit();
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'semaphore');
+});
+
+test.serial('Shippable', t => {
+  process.env.SHIPPABLE = 'true';
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'shippable');
+});
+
+test.serial('Travis', t => {
+  process.env.TRAVIS = 'true';
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'travis');
+});
+
+test.serial('Wercker', t => {
+  process.env.WERCKER_MAIN_PIPELINE_STARTED = '123456';
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.is(env.service, 'wercker');
+});
+
+test.serial('Unknown CI and Git repository', async t => {
+  process.env.CI = 'true';
+  await gitRepo();
+  await gitCommit();
+
+  const env = m();
+  t.is(env.isCi, true);
+  t.falsy(env.service);
+});
+
+test.serial('Unknown CI and not a Git repository', t => {
+  process.env.CI = 'true';
+  process.chdir(tempy.directory());
+  const env = m();
+
+  t.is(env.isCi, true);
+  t.falsy(env.service);
+});
+
+test.serial('Not CI', t => {
+  process.chdir(tempy.directory());
+  const env = m();
+
+  t.is(env.isCi, false);
+  t.falsy(env.service);
+});
diff --git a/test/jenkins.test.js b/test/jenkins.test.js
new file mode 100644
index 0000000..50e1473
--- /dev/null
+++ b/test/jenkins.test.js
@@ -0,0 +1,71 @@
+import test from 'ava';
+import jenkins from '../lib/jenkins';
+
+test('Push', t => {
+  process.env.JENKINS_URL = 'http://jenkins.jenkins.example/';
+  process.env.GIT_COMMIT = '5678';
+  process.env.GIT_BRANCH = 'master';
+  process.env.BUILD_NUMBER = '91011';
+  process.env.WORKSPACE = '/';
+  delete process.env.BRANCH_NAME;
+  delete process.env.ghprbActualCommit;
+  delete process.env.ghprbSourceBranch;
+  delete process.env.CHANGE_ID;
+  delete process.env.ghprbPullId;
+
+  t.deepEqual(jenkins.configuration(), {
+    service: 'jenkins',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    pr: undefined,
+    isPr: false,
+  });
+});
+
+test('PR', t => {
+  process.env.JENKINS_URL = 'http://jenkins.jenkins.example/';
+  process.env.GIT_COMMIT = '5678';
+  process.env.BRANCH_NAME = 'pr_branch';
+  process.env.BUILD_NUMBER = '91011';
+  process.env.WORKSPACE = '/';
+  process.env.CHANGE_ID = '10';
+  delete process.env.GIT_BRANCH;
+  delete process.env.ghprbActualCommit;
+  delete process.env.ghprbSourceBranch;
+  delete process.env.ghprbPullId;
+
+  t.deepEqual(jenkins.configuration(), {
+    service: 'jenkins',
+    commit: '5678',
+    build: '91011',
+    branch: 'pr_branch',
+    root: '/',
+    pr: '10',
+    isPr: true,
+  });
+});
+
+test('PR (PR builder)', t => {
+  process.env.JENKINS_URL = 'http://jenkins.jenkins.example/';
+  process.env.ghprbActualCommit = '5678';
+  process.env.ghprbSourceBranch = 'pr_branch';
+  process.env.BUILD_NUMBER = '91011';
+  process.env.WORKSPACE = '/';
+  process.env.ghprbPullId = '10';
+  delete process.env.GIT_BRANCH;
+  delete process.env.GIT_COMMIT;
+  delete process.env.BRANCH_NAME;
+  delete process.env.CHANGE_ID;
+
+  t.deepEqual(jenkins.configuration(), {
+    service: 'jenkins',
+    commit: '5678',
+    build: '91011',
+    branch: 'pr_branch',
+    root: '/',
+    pr: '10',
+    isPr: true,
+  });
+});
diff --git a/test/semaphore.test.js b/test/semaphore.test.js
new file mode 100644
index 0000000..c016a05
--- /dev/null
+++ b/test/semaphore.test.js
@@ -0,0 +1,57 @@
+import test from 'ava';
+import semaphore from '../lib/semaphore';
+import {gitRepo, gitCommit} from './helpers/git-utils';
+
+// Save the current working diretory
+const cwd = process.cwd();
+
+test.beforeEach(async () => {
+  await gitRepo();
+});
+
+test.afterEach.always(() => {
+  // Restore the current working directory
+  process.chdir(cwd);
+});
+
+test.serial('Push', async t => {
+  const commit = await gitCommit();
+  process.env.SEMAPHORE = 'true';
+  process.env.SEMAPHORE_BUILD_NUMBER = '91011';
+  process.env.BRANCH_NAME = 'master';
+  process.env.SEMAPHORE_PROJECT_DIR = '/';
+  process.env.SEMAPHORE_REPO_SLUG = 'owner/repo';
+  delete process.env.PULL_REQUEST_NUMBER;
+
+  t.deepEqual(semaphore.configuration(), {
+    service: 'semaphore',
+    commit,
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    pr: undefined,
+    isPr: false,
+    slug: 'owner/repo',
+  });
+});
+
+test.serial('PR', async t => {
+  const commit = await gitCommit();
+  process.env.SEMAPHORE = 'true';
+  process.env.SEMAPHORE_BUILD_NUMBER = '91011';
+  process.env.BRANCH_NAME = 'master';
+  process.env.PULL_REQUEST_NUMBER = '10';
+  process.env.SEMAPHORE_PROJECT_DIR = '/';
+  process.env.SEMAPHORE_REPO_SLUG = 'owner/repo';
+
+  t.deepEqual(semaphore.configuration(), {
+    service: 'semaphore',
+    commit,
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    pr: '10',
+    isPr: true,
+    slug: 'owner/repo',
+  });
+});
diff --git a/test/shippable.test.js b/test/shippable.test.js
new file mode 100644
index 0000000..9773ec8
--- /dev/null
+++ b/test/shippable.test.js
@@ -0,0 +1,52 @@
+import test from 'ava';
+import shippable from '../lib/shippable';
+
+test('Push', t => {
+  process.env.SHIPPABLE = 'true';
+  process.env.JOB_NUMBER = '1234';
+  process.env.COMMIT = '5678';
+  process.env.BUILD_NUMBER = '91011';
+  process.env.BRANCH = 'master';
+  process.env.PULL_REQUEST = 'false';
+  process.env.IS_PULL_REQUEST = 'false';
+  process.env.SHIPPABLE_BUILD_DIR = '/';
+  process.env.SHIPPABLE_REPO_SLUG = 'owner/repo';
+  delete process.env.BASE_BRANCH;
+
+  t.deepEqual(shippable.configuration(), {
+    service: 'shippable',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    job: '1234',
+    pr: undefined,
+    isPr: false,
+    slug: 'owner/repo',
+  });
+});
+
+test('PR', t => {
+  process.env.SHIPPABLE = 'true';
+  process.env.JOB_NUMBER = '1234';
+  process.env.COMMIT = '5678';
+  process.env.BUILD_NUMBER = '91011';
+  process.env.BASE_BRANCH = 'master';
+  process.env.PULL_REQUEST = '10';
+  process.env.IS_PULL_REQUEST = 'true';
+  process.env.SHIPPABLE_BUILD_DIR = '/';
+  process.env.SHIPPABLE_REPO_SLUG = 'owner/repo';
+  delete process.env.BRANCH;
+
+  t.deepEqual(shippable.configuration(), {
+    service: 'shippable',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    job: '1234',
+    pr: '10',
+    isPr: true,
+    slug: 'owner/repo',
+  });
+});
diff --git a/test/travis.test.js b/test/travis.test.js
new file mode 100644
index 0000000..e16def4
--- /dev/null
+++ b/test/travis.test.js
@@ -0,0 +1,48 @@
+import test from 'ava';
+import travis from '../lib/travis';
+
+test('Push', t => {
+  process.env.TRAVIS = 'true';
+  process.env.TRAVIS_JOB_NUMBER = '1234';
+  process.env.TRAVIS_COMMIT = '5678';
+  process.env.TRAVIS_BUILD_NUMBER = '91011';
+  process.env.TRAVIS_BRANCH = 'master';
+  process.env.TRAVIS_PULL_REQUEST = 'false';
+  process.env.TRAVIS_BUILD_DIR = '/';
+  process.env.TRAVIS_REPO_SLUG = 'owner/repo';
+
+  t.deepEqual(travis.configuration(), {
+    service: 'travis',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    job: '1234',
+    pr: undefined,
+    isPr: false,
+    slug: 'owner/repo',
+  });
+});
+
+test('PR', t => {
+  process.env.TRAVIS = 'true';
+  process.env.TRAVIS_JOB_NUMBER = '1234';
+  process.env.TRAVIS_COMMIT = '5678';
+  process.env.TRAVIS_BUILD_NUMBER = '91011';
+  process.env.TRAVIS_BRANCH = 'master';
+  process.env.TRAVIS_PULL_REQUEST = '10';
+  process.env.TRAVIS_BUILD_DIR = '/';
+  process.env.TRAVIS_REPO_SLUG = 'owner/repo';
+
+  t.deepEqual(travis.configuration(), {
+    service: 'travis',
+    commit: '5678',
+    build: '91011',
+    branch: 'master',
+    root: '/',
+    job: '1234',
+    pr: '10',
+    isPr: true,
+    slug: 'owner/repo',
+  });
+});
diff --git a/test/wercker.test.js b/test/wercker.test.js
new file mode 100644
index 0000000..ef6b50c
--- /dev/null
+++ b/test/wercker.test.js
@@ -0,0 +1,20 @@
+import test from 'ava';
+import wercker from '../lib/wercker';
+
+test('Push', t => {
+  process.env.WERCKER_MAIN_PIPELINE_STARTED = '123456';
+  process.env.WERCKER_GIT_COMMIT = '5678';
+  process.env.WERCKER_GIT_BRANCH = 'master';
+  process.env.WERCKER_ROOT = '/';
+  process.env.WERCKER_GIT_OWNER = 'owner';
+  process.env.WERCKER_GIT_REPOSITORY = 'repo';
+
+  t.deepEqual(wercker.configuration(), {
+    service: 'wercker',
+    commit: '5678',
+    build: '123456',
+    branch: 'master',
+    root: '/',
+    slug: 'owner/repo',
+  });
+});