eslint-plugin-protractor

ESLint rules for Protractor

This plugin would not only help catch common Protractor-specific errors early, follow the best practices for writing Protractor tests, but would also help maintaining good and reliable element locators.

The plugin would be of the most help if configured to run in your IDE of choice on the fly.

This gif shows integration of ESLint with eslint-plugin-protractor into WebStorm IDE. Find out more at WebStorm ESLint configuration.

Installation

Install ESLint and this plugin either locally or globally.

$ npm install eslint --save-dev
$ npm install eslint-plugin-protractor --save-dev

Usage

1. Install eslint-plugin-protractor as a dev-dependency:

   npm install --save-dev eslint-plugin-protractor

2. Enable the plugin by adding it to your .eslintrc:

   plugins:
     - protractor

Rules

There are various types of rules implemented in the plugin. Here is a rough categorization.

Correct Protractor API usage and Common Errors

• missing-perform: Enforce valid browser.actions() usage
• correct-chaining: Prohibit incorrect chaining of element and element.all
• no-array-finder-methods: Disallow using ElementArrayFinder methods on ElementFinder
• array-callback-return: Enforce return statements in callbacks of ElementArrayFinder methods
• no-get-inner-outer-html: Warn about using deprecated getInnerHtml() and getOuterHtml() methods
• no-get-raw-id: Warn about using removed getRawId() method
• no-get-location-abs-url: Warn about using deprecated getLocationAbsUrl() method
• no-promise-in-if: Warn if promise is checked for truthiness inside an if condition
• bare-element-finders: Warn if a bare ElementFinder or ElementArrayFinder is declared with no applied action
• empty-script: Warn if executeScript() or executeAsyncScript() are called with missing or empty script

Locating Elements

• no-invalid-selectors: Prohibit creating invalid CSS selectors
• valid-locator-type: Ensure correct locator argument type for element(), element.all(), $() and $$()
• no-compound-classes: Do not allow compound class names in the by.className() locator
• no-angular-classes: Discourage using Angular CSS classes inside CSS selectors
• use-angular-locators: Recommend using built-in Angular-specific locators
• no-angular-attributes: Discourage using Angular attributes inside CSS selectors
• no-bootstrap-classes: Discourage using Bootstrap layout-oriented CSS classes inside CSS selectors
• use-simple-repeaters: Discourage using extended ng-repeat syntax in by.repeater() locators
• no-repetitive-locators: Discourage repeating locators
• no-repetitive-selectors: Discourage repeating parts of CSS selectors
• valid-by-id: Prohibit use of invalid ID value when using by.id() locator
• valid-by-tagname: Prohibit use of invalid Html Tag Name value when using by.tagName() locator
• limit-selector-depth: Warn about potentially "deep" CSS selectors with too many nodes in the path

Style Guide Recommendations and Best Practices

• missing-wait-message: Missing wait timeout message in browser.wait()
• no-by-xpath: Discourage the use of by.xpath() locator
• no-get-in-it: Recommend against having browser.get() or browser.driver.get() inside it()
• no-execute-script: Recommend against executing scripts in specs and page objects
• no-expect-in-po: Recommend against making assertions inside Page Objects
• no-absolute-url: Recommend against navigating to absolute URLs inside browser.get() or browser.driver.get()
• use-first-last: Recommend using first() instead of get(0) and last() instead of get(-1)
• no-shadowing: Don't allow to shadow the built-in Protractor globals
• use-count-method: Recommend using count() instead of then() and length
• use-promise-all: Recommend using protractor.promise.all() to resolve multiple promises
• by-css-shortcut: Recommend using $ and $$ shortcuts
• no-describe-selectors: Discourage nested selectors within describe blocks
• no-browser-pause: Discourage the use of browser.pause()
• no-browser-sleep: Discourage the use of browser.sleep()
• no-browser-driver: Discourage the use of browser.driver instead of browser directly

Here is a table with all the available rules sorted by the default error level:

Rule	Default Error Level	Auto-fixable	Options
missing-perform	2 (Error)
no-browser-pause	2
correct-chaining	2	Yes
no-invalid-selectors	2
no-array-finder-methods	2
valid-locator-type	2
no-compound-classes	2
no-get-inner-outer-html	2
no-get-raw-id	2
missing-wait-message	1 (Warning)
no-browser-sleep	1
no-by-xpath	1
no-describe-selectors	1
no-angular-classes	1
use-angular-locators	1
no-angular-attributes	1
no-bootstrap-classes	1
use-simple-repeaters	1
no-shadowing	1
use-first-last	1	Yes
no-get-in-it	1
array-callback-return	1
no-absolute-url	1
no-get-location-abs-url	1
no-expect-in-po	1		requires plugin "settings"
no-promise-in-if	1
no-execute-script	1		requires plugin "settings"
no-repetitive-locators	1
no-repetitive-selectors	1
use-count-method	1
valid-by-id	1
valid-by-tagname	1
limit-selector-depth	1		number of nodes (default 5)
bare-element-finders	1
empty-script	1
use-promise-all	0 (Turned off)
by-css-shortcut	0
no-browser-driver	0

For example, the missing-perform rule is enabled by default and will cause ESLint to throw an error (with an exit code of 1) when triggered.

The requires plugin "settings" note indicates that a rule needs the plugin to have configured settings in your ESLint config. For example, no-execute-script rule expects configured paths to either spec, or page object files, or both.

You may customise each rule by adding a value in your .eslintrc rules property:

plugins:
  - protractor
rules:
  protractor/missing-perform: 0

See configuring rules for more information.

Recommended configuration

This plugin export a recommended configuration that enforce good practices.

To enable this configuration use the extends property in your .eslintrc config file:

{
  "plugins": [
    "protractor"
  ],
  "extends": "plugin:protractor/recommended"
}

See ESLint documentation for more information about extending configuration files.

Author

© 2016-infinity Alexander Afanasyev and contributors.

License

Licensed under the MIT license.