gplint (Gherkin/Pickle Linter)

Uses Gherkin to parse feature files and runs linting against the default rules, and the optional rules you specified in your .gplintrc file.

Forked from gherkin-lint

Installation

npm install gplint

Demo

To see the output for all the errors that the linter can detect run:

git clone https://github.com/Nyaran/gplint.git
npm run demo

Or check this:

Available rules

Rules with ⚙️ means that allows auto-fix with --fix argument.

Name	Functionality
no-tags-on-backgrounds *	Disallows tags on Background
one-feature-per-file *	Disallows multiple Feature definitions in the same file
up-to-one-background-per-file *	Disallows multiple Background definition in the same file
no-multiline-steps *	Disallows multiline Steps
allowed-tags	Just the listed tags are allowed
allow-all-caps	Allows the user to specify if some nodes allows texts completely in uppercase.
allow-all-lowercase	Allows the user to specify if some nodes allows texts completely in lowercase.
file-name	Restrict feature file names to a common style
⚙️ indentation	Allows the user to specify indentation rules
keywords-in-logical-order	Requires that Given, When and Then appear in logical sequence
max-scenarios-per-file	Allows the user to specify the max number of scenarios per feature file
max-tags-lines	Allows the user to specify the max number of lines for tags in each level.
name-length	Allows restricting length of Feature/Scenario/Step names
new-line-at-eof	Disallows/enforces new line at EOF
no-background-only-scenario	Disallows background when there is just one scenario
no-dupe-feature-names	Disallows duplicate Feature names
no-dupe-scenario-names	Disallows duplicate Scenario names
no-duplicate-tags	Disallows duplicate tags on the same Feature or Scenario
no-empty-background	Disallows features with backgrounds without steps
no-empty-file	Disallows empty feature files
no-examples-in-scenarios	Disallow the use of "Examples" in Scenarios, only allowed in Scenario Outlines
no-files-without-scenarios	Disallows files with no scenarios
no-homogenous-tags	Disallows tags present on every Scenario/Rule in a Feature or Rule, rather than on the Feature/Rule itself. Skips if contains a single scenario
no-multiple-empty-lines	Disallows multiple empty lines
no-partially-commented-tag-lines	Disallows partially commented tag lines
no-restricted-patterns	A list of patterns to disallow globally, or specifically in features, rules, backgrounds, scenarios, or scenario outlines, Steps
no-restricted-tags	Disallow use of particular @tags
no-scenario-outlines-without-examples	Disallows scenario outlines without examples
no-superfluous-tags	Disallows tags present on a Node, its parents (E.g. Same tags in a Scenario and/or Example, and also on the Feature or Rule that contains it
⚙️ no-trailing-spaces	Disallows trailing spaces
no-unnamed-features	Disallows empty Feature name
no-unnamed-scenarios	Disallows empty Scenario name
no-unused-variables	Disallows unused variables in scenario outlines
one-space-between-tags	Tags on the same line must be separated by a single space
required-tags	Require tags/patterns of tags
related-tags	Tags that requires other tags.
scenario-size	Allows restricting the maximum number of steps in a scenario, scenario outline and background
table-align	Allows to force table alignment on steps and/or examples.
use-and	Disallows repeated step names requiring use of And instead

* These rules cannot be turned off because they detect undocumented cucumber functionality that causes the gherkin parser to crash.

Rule Configuration

The not-configurable rules are turned on by default and cannot be turned off. Configurable rules can be customized using a file.

The configurable rules are off by default. To turn them on, you will need to create a json file, where you specify the name of each rule and its desired level (which can be "error" or "warn" or "off"). Eg:

{
  "no-unnamed-features": "error"
}

will turn on the no-unnamed-features rule.

allowed-tags

allowed-tags should be configured with the list of allowed tags and patterns:

{
  "allowed-tags": ["error", {"tags": ["@watch", "@wip"], "patterns": ["^@todo$"]}]
}

Any tag not included in this list won't be allowed.

allow-all-caps / allow-all-lowercase

allow-all-caps / allow-all-lowercase should be configured with the list of allowed tags and patterns:

{
  "allow-all-caps": ["error", {
    "Global": false,
    "Description": true,
    "ExampleHeader": true,
    "ExampleBody":  true
  }] ,
  "allow-all-lowercase": ["error", {
    "Global": false,
    "Description": true,
    "ExampleHeader": true,
    "ExampleBody":  true
  }]
}

• Global: If a node is not specified, "Global" is applied. Default value is false.
• Description: Apply to all descriptions for any node.
• Feature: Apply to Feature title.
• Rule: Apply to Rule title.
• Background: Apply to Background title.
• Scenario: Apply to Scenario title.
• Step: Apply to Step value.
• Example: Apply to Example title.
• ExampleHeader: Apply to each header of Example tables.
• ExampleBody: Apply to each value of Example tables.

file-name

file-name is configured with a style to enforce. The default is PascalCase:

{
  "file-name": ["error", {"style": "PascalCase"}]
}

The list of supported styles is:

• PascalCase - first letter of each word capitalized (no spaces) e.g. "MyFancyFeature.feature"
• Title Case - first letter of each word capitalized (with spaces) e.g. "My Fancy Feature.feature"
• camelCase - first letter of each word capitalized, except first e.g. "myFancyFeature.feature"
• kebab-case - all lowercase, hyphen-delimited e.g. "my-fancy-feature.feature"
• snake_case - all lowercase, underscore-delimited e.g. "my_fancy_feature.feature"

Acronyms on camelCase

If you are using acronyms with the style camelCase and you want to preserve them capitalized, you can set the allowAcronyms property to true:

{
  "file-name": ["error", {"style": "camelCase", "allowAcronyms": true}]
}

• camelCase - first letter of each word capitalized, except first e.g. "myFancyFeatureACRON.feature"

no-partially-commented-tag-lines

Disallows partially commented tag lines. You can configure if a comment is allowed if is separated with a space or not allowed at all:

Allow separated (Default)

{
  "no-partially-commented-tag-lines": ["error", {"allowSeparated": true}]
}

The following table illustrates how it works:

Example	Description	Result
@foo	Without a comment	Valid
@foo #comment	With a comment separated with space	Valid
@foo#comment	With a comment non-separated	Invalid

Not allow separated

{
  "no-partially-commented-tag-lines": ["error", {"allowSeparated": false}]
}

The following table illustrates how it works:

Example	Description	Result
@foo	Without a comment	Valid
@foo #comment	With a comment separated with space	Invalid
@foo#comment	With a comment non-separated	Invalid

no-restricted-patterns

no-restricted-patterns is a list of exact or partial patterns whose matches are disallowed in feature name and description, and in background, scenario and scenario outline name, description and steps. All patterns are treated as case-insensitive. The rule can be configured like this:

{
  "no-restricted-patterns": ["error", {
    "Global": [
      "^globally restricted pattern"
    ],
    "Feature": [
      "poor description",
      "validate",
      "verify"
    ],
    "Background": [
      "show last response",
      "a debugging step"
    ],
    "Scenario": [
      "show last response",
      "a debugging step"
    ],
    "Examples": [
      "poor examples name",
      "really bad examples description"
    ],
    "ExampleHeader": [
      "^.*disallowed.*$"
    ],
    "ExampleBody": [
      "^.*invalid.*$"
    ],
    "Step": [
      "bad step"
    ],
    "Given": [
      "bad step given",
      "a debugging step given"
    ],
    "When": [
      "bad step when",
      "a debugging step when"
    ],
    "Then": [
      "bad step then",
      "a debugging step then"
    ],
    "DocString": [
      "^.*disallowed.*$"
    ],
    "DataTable": [
      "^.*invalid.*$",
      "wrong value"
    ]
  }]
}

Notes:

• Description violations always get reported in the Feature/Scenario/etc. definition line. This is due to the parsed gherkin tree not having information about which line the description appears.

indentation

indentation can be configured in a more granular level and uses following rules by default:

• Expected indentation for Feature, Background, Scenario, Examples heading: 0 spaces
• Expected indentation for Steps and each example: 2 spaces

You can override the defaults for indentation like this:

{
  "indentation" : [
    "error", {
      "Feature": 0,
      "Background": 0,
      "Scenario": 0,
      "Step": 2,
      "Examples": 0,
      "example": 2,
      "given": 2,
      "when": 2,
      "then": 2,
      "and": 2,
      "but": 2,
      "feature tag": 0,
      "scenario tag": 0,
      "examples tag": 0
    }
  ]
}

There is no need to override all the defaults, as is done above, instead they can be overridden only where required. Step will be used as a fallback if the keyword of the step, e.g. 'given', is not specified. If feature tag is not set then Feature is used as a fallback, and if scenario tag is not set then Scenario is used as a fallback.

This feature is able to handle all localizations of the gherkin steps.

max-scenarios-per-file

The max-scenarios-per-file supports some configuration options:

• maxScenarios (number) the maximum scenarios per file after which the rule fails - defaults to 10
• countOutlineExamples (boolean) whether to count every example row for a Scenario Outline, as opposed to just 1 for the whole block - defaults to true

The configuration looks like this (showing the defaults):

{
  "max-scenarios-per-file": ["error", {"maxScenarios": 10, "countOutlineExamples": true}]
}

max-tags-lines

max-tags-lines lets the user specify the maximum allowed lines for tags per level type. Each level type can be configured separately.

Example configuration wth default values:

{
  "max-tags-lines": [
    "error",
    {
      "feature": 1,
      "scenario": 5,
      "example": 5
    }
  ]
}

name-length

name-length can be configured separately for Feature, Scenario and Step names. The default is 70 characters for each of these:

{
  "name-length" : ["error", { "Feature": 70, "Scenario": 70, "Step": 70 }]
}

new-line-at-eof

new-line-at-eof can be configured to enforce or disallow new lines at EOF.

• To enforce new lines at EOF:

{
  "new-line-at-eof": ["error", "yes"]
}

• To disallow new lines at EOF:

{
  "new-line-at-eof": ["error", "no"]
}

no-dupe-scenario-names

no-dupe-scenario-names can be configured to search for duplicates in each individual feature or amongst all feature files. The default case is testing against all the features (same scenario name in different features will raise an error). To get that behavior use the following configuration:

{
  "no-dupe-scenario-names": "error"
}

You can specify the scope, by using different configuration options:

anywhere

Same as the default behaviour, find duplicates along all files.

{
  "no-dupe-scenario-names": ["error", "anywhere"]
}

in-feature

To enable searching for duplicates in each individual feature (same scenario name in different features won't raise an error) you need to configure the rule like this:

{
  "no-dupe-scenario-names": ["error", "in-feature"]
}

in-rule

To enable searching for duplicates in each individual rule (same scenario name in different rules won't raise an error) you need to configure the rule like this:

{
  "no-dupe-scenario-names": ["error", "in-rule"]
}

The "-compile" suffix

Additionally, you can also look for duplicated on Outline Scenarios with variables on the title, just adding -compile suffix to the rule configuration (If you use this option, you need to have a variable on the title of all your Outlines):

anywhere-compile

Same as the default behaviour, find duplicates along all files, including compiling Outlines:

{
  "no-dupe-scenario-names": ["error", "anywhere-compile"]
}

in-feature-compile

Same as in-feature, but including compiling Outlines:

{
  "no-dupe-scenario-names": ["error", "in-feature-compile"]
}

in-rule-compile

Same as in-rule, but including compiling Outlines:

{
  "no-dupe-scenario-names": ["error", "in-rule-compile"]
}

no-restricted-tags

no-restricted-tags should be configured with the list of restricted tags and patterns:

{
  "no-restricted-tags": ["error", {"tags": ["@watch", "@wip"], "patterns": ["^@todo$"]}]
}

keywords-in-logical-order

keywords-in-logical-order Allows the user to maintain the wording order by using the scenario keywords, following the Given, When, Then sequence.

• detectMissingKeywords (boolean): whether to ignore the lack of some keyword that violates the structure - defaults to false. Example configuration with default values:

{
  "keywords-in-logical-order": [
    "error",
    { 
      "detectMissingKeywords": false
    }
  ]
}

required-tags

required-tags supports some configuration options:

• ignoreUntagged (boolean): whether to ignore scenarios that have no tag - defaults to true.
• global (array): the array of tag patterns that must match - defaults to []
• feature (array): the array of tag patterns that must match - defaults to []
• rule (array): the array of tag patterns that must match - defaults to []
• scenario (array): the array of tag patterns that must match - defaults to []
• example (array): the array of tag patterns that must match - defaults to []
• extendRule (boolean): When Scenario is not contained inside Rule, extends required rule tags to scenario - defaults to false
• extendExample (boolean): When Scenario is not a Scenario Outline, extends required example tags to scenario - defaults to false

* All levels allows to define a sub-array to mark only one of the members of array as required.

{
  "required-tags": [
    "error",
    {
      "global": ["/^@ID\\.APP-[0-9]+$/"],
      "feature": ["/@feature\\..+/"],
      "rule": ["/^@user-case\\..+$/"],
      "scenario": [["@ready", "@manual", "@wip"]],
      "example": ["/^@type\\..+$/"],
      "extendRule": true,
      "extendExample": true,
      "ignoreUntagged": false
    }
  ]
}

related-tags

related-tags allow to define a list of tags with a list of related tags that should be present too. The related tags can be an string or a regular expression (represented as a string between slashes /)

{
  "related-tags": ["error", {
    "tags": {
      "@disable": ["/^@TICKET.PROJ-[0-9]+$/"],
      "@a-tag": ["@otherTag", "@otherTagBis"]
    }
  }]
}

scenario-size

scenario-size lets you specify a maximum step length for scenarios and backgrounds. The Scenario configuration applies to both scenarios and scenario outlines:

{
  "scenario-size": ["error", { "steps-length": { "Background": 15, "Scenario": 15 }}]
}

table-align

table-align lets you specify if tables must be aligned or not. This can be activated for steps and for examples (by default both are activated):

{
  "table-align": ["error", { "steps": true, "examples": true }]
}

Configuration File

The default name for the configuration file is .gplintrc and it's expected to be in your working directory.

The file contents must be valid JSON, though it does allow comments.

If you are using a file with a different name or a file in a different folder, you will need to specify the -c or --config option and pass in the relative path to your configuration file. Eg: gplint -c path/to/configuration/file.extension

You can find an example configuration file, that turns on all the rules in the root of this repo (.gplintrc).

Configure rule level

Each should have a rule level configured, there are 3 available levels

• "off" or "0": Turn the rule off.
• "warn" or "1" or 1: Turn the rule on, without affection exit code.
• "error" or "2" or 2: Turn the rule on, setting exit code to 1 when triggered.

Note: "warn" can provoke an exit code 1 if --max-warnings is provided with 0 or greater value.

Ignoring Feature Files

There are 2 ways you can specify files that the linter should ignore:

1. Add a .gplintignore file in your working directory and specify one glob pattern per file line
2. Use the command line option-i or --ignore, pass in a comma separated list of glob patterns. If specified, the command line option will override the .gplintignore file.

Custom rules

You can specify one more custom rules directories by using the -r or --rulesdir command line option. Rules in the given directories will be available additionally to the default rules.

Example:

gplint --rulesdir "/path/to/my/rulesdir" --rulesdir "from/cwd/rulesdir"

Paths can either be absolute or relative to the current working directory. Have a look at the src/rules/ directory for examples; The no-empty-file rule is a good example to start with.