feat(rules): add 'no-expect-in-po' rule

Author: alecxe

README.md

@@ -35,7 +35,7 @@
 This plugin ships with a default configuration for each rule:
 
 Rule                         | Default       | Options
-----                         | -------       | -------
+----                         | -------       | ---------
 [missing-perform][]          | 2             |
 [no-browser-pause][]         | 2             |
 [missing-wait-message][]     | 1             |
@@ -51,6 +51,7 @@ Rule                         | Default       | Options
 [no-get-in-it][]             | 1             |
 [array-callback-return][]    | 1             |
 [no-absolute-url][]          | 1             |
+[no-expect-in-po][]          | 1             | requires plugin "settings"
 [by-css-shortcut][]          | 0             |
 
 For example, the `missing-perform` rule is enabled by default and will cause
@@ -84,6 +85,7 @@ See [configuring rules][] for more information.
 [array-callback-return]: docs/rules/array-callback-return.md
 [no-absolute-url]: docs/rules/no-absolute-url.md
 [by-css-shortcut]: docs/rules/by-css-shortcut.md
+[no-expect-in-po]: docs/rules/no-expect-in-po.md
 [configuring rules]: http://eslint.org/docs/user-guide/configuring#configuring-rules
 
 ## Recommended configuration

docs/rules/no-expect-in-po.md

@@ -0,0 +1,23 @@
+# Recommend against making assertions inside Page Objects
+
+This rule enforces the [Avoid using `expect()` in page objects](https://github.com/angular/protractor/blob/master/docs/style-guide.md#avoid-using-expect-in-page-objects) Protractor Style Guide recommendation.
+
+**Important:** This rule requires plugin `settings` to have the configured "glob"-style paths (see [`minimatch`](https://github.com/isaacs/minimatch) to learn more about the supported "glob" syntax) to distinguish Page Object files from others. 
+
+Edit your ESLint config and add (this is example configuration):
+
+    settings: {
+      "eslint-plugin-protractor":
+        paths: {
+          po: ["**/test/e2e/po/*.po.js"]
+        }
+      }
+    }
+
+If this setting is not present, the rule would be disabled.
+
+*Note: Because ESLint uses absolute paths and it is difficult to correctly locate base path of your project from within a plugin, so it is highly suggested to use complete paths to folders you want to disable to leverage the risk of targeting wrong directories and files.*
+
+## Rule details
+
+This rule would warn if it sees `expect()` function call inside a file that matches at least one of the patterns configured in paths/po array.

index.js

@@ -16,6 +16,7 @@ var useFirstLast = require('./lib/rules/use-first-last')
 var noGetInIt = require('./lib/rules/no-get-in-it')
 var arrayCallbackReturn = require('./lib/rules/array-callback-return')
 var noAbsoluteURL = require('./lib/rules/no-absolute-url')
+var noExpectInPO = require('./lib/rules/no-expect-in-po')
 
 module.exports = {
   rules: {
@@ -34,7 +35,8 @@ module.exports = {
     'use-first-last': useFirstLast,
     'no-get-in-it': noGetInIt,
     'array-callback-return': arrayCallbackReturn,
-    'no-absolute-url': noAbsoluteURL
+    'no-absolute-url': noAbsoluteURL,
+    'no-expect-in-po': noExpectInPO
   },
   configs: {
     recommended: {
@@ -54,6 +56,7 @@ module.exports = {
         'protractor/no-get-in-it': 1,
         'protractor/array-callback-return': 1,
         'protractor/no-absolute-url': 1,
+        'protractor/no-expect-in-po': 1,
         'protractor/by-css-shortcut': 0
       },
       globals: {

lib/rules/no-expect-in-po.js

@@ -0,0 +1,46 @@
+'use strict'
+
+/**
+ * @fileoverview Recommend against making assertions inside Page Objects
+ * @author Alexander Afanasyev
+ */
+
+var PLUGIN_NAME = 'eslint-plugin-protractor'
+var multimatch = require('multimatch')
+
+module.exports = {
+  meta: {
+    schema: []
+  },
+
+  create: function (context) {
+    // do nothing if appropriate settings are not present
+    var settings = context.settings
+    if (!settings || !settings[PLUGIN_NAME] || !settings[PLUGIN_NAME].paths || !settings[PLUGIN_NAME].paths.po) {
+      return {}
+    }
+
+    // get glob matches
+    var filename = context.getFilename()
+    var patterns = settings[PLUGIN_NAME].paths.po
+    var matches = multimatch(filename, patterns)
+
+    // do nothing if a filename does not match pre-configured patterns
+    if (!matches || matches.length === 0) {
+      return {}
+    }
+
+    return {
+      'CallExpression': function (node) {
+        var callee = node.callee
+
+        if (callee && callee.name === 'expect') {
+          context.report({
+            node: node,
+            message: 'Unexpected "expect()" inside a Page Object'
+          })
+        }
+      }
+    }
+  }
+}

package.json

@@ -63,6 +63,7 @@
     }
   },
   "dependencies": {
-    "css-selector-parser": "^1.1.0"
+    "css-selector-parser": "^1.1.0",
+    "multimatch": "^2.1.0"
   }
 }

test/rules/no-expect-in-po.js

@@ -0,0 +1,112 @@
+'use strict'
+
+var rule = require('../../lib/rules/no-expect-in-po')
+var RuleTester = require('eslint').RuleTester
+var eslintTester = new RuleTester()
+
+eslintTester.run('no-expect-in-po', rule, {
+  valid: [
+    {
+      code: 'var test = "bar"'
+    },
+
+    {
+      code: 'expect(1).toEqual(1);'
+    },
+
+    {
+      code: 'expect(2).toEqual(2);',
+      'eslint-plugin-protractor': {
+        settings: {
+          paths: {
+            po: ['*.po.js']
+          }
+        }
+      },
+      filename: 'test.spec.js'
+    },
+
+    {
+      code: 'expect(3).toEqual(3);',
+      'eslint-plugin-protractor': {
+        settings: {
+          paths: {
+            po: ['*.somethingelse.js']
+          }
+        }
+      },
+      filename: 'test.po.js'
+    },
+
+    {
+      code: 'expect(4).toEqual(4);',
+      'eslint-plugin-protractor': {
+        settings: {
+          paths: {
+            po: []
+          }
+        }
+      },
+      filename: 'test.po.js'
+    },
+
+    {
+      code: 'expect(5).toEqual(5);',
+      'eslint-plugin-protractor': {
+        settings: {
+          paths: {
+            po: ['*.somethingelse1.js', '*.somethingelse2.js']
+          }
+        }
+      },
+      filename: 'test.po.js'
+    }
+  ],
+
+  invalid: [
+    {
+      code: 'expect(-1).toEqual(-1);',
+      settings: {
+        'eslint-plugin-protractor': {
+          paths: {
+            po: ['**/po/*.po.js']
+          }
+        }
+      },
+      filename: '/var/app/test/e2e/po/test.po.js',
+      errors: [{
+        message: 'Unexpected "expect()" inside a Page Object'
+      }]
+    },
+
+    {
+      code: 'expect(-2).toEqual(-2);',
+      settings: {
+        'eslint-plugin-protractor': {
+          paths: {
+            po: ['**/*.js']
+          }
+        }
+      },
+      filename: '/var/app/test/e2e/po/test.po.js',
+      errors: [{
+        message: 'Unexpected "expect()" inside a Page Object'
+      }]
+    },
+
+    {
+      code: 'expect(-3).toEqual(-3);',
+      settings: {
+        'eslint-plugin-protractor': {
+          paths: {
+            po: ['**/*.somethingelse1.js', '**/*.po.js', '**/*.somethingelse2.js']
+          }
+        }
+      },
+      filename: '/var/app/test/e2e/po/test.po.js',
+      errors: [{
+        message: 'Unexpected "expect()" inside a Page Object'
+      }]
+    }
+  ]
+})