gherkin-precompiler

gherkin-precompiler

Simple pre-compiler for Gherkin feature files.

It is based on the AST what is provided by gherkin-assembler.

Usage

'use strict';
const compiler = require('gherkin-precompiler');

let ast = compiler.load('./features/src/login.feature');
ast = compiler.process(
    ast,
    new compiler.builtIn.Replacer({
        name: 'Hello'
    })
);
compiler.save('./features/dist/login.feature', ast, {
    lineBreak: '\r\n'
});

Built-in pre compilers

• Replacer

  Replaces keywords in the feature files.

API

load

It loads the given feature file to a GherkinDocument.

Params:

• {string} pathToFile - the path of the feature file which needs to be loaded

Returns: {GherkinDocument} the AST of the given feature file

save

Saves the given AST ast feature file to the given path.

Params:

• {string} pathToFile - the path of the feature file where the AST needs to be saved
• {GherkinDocument} ast - the AST needs to be saved to the file
• {AssemblerConfig} [options] - configuration of formatting, see AssemblerConfig

process

Applies the given pre-compilers to the given AST.

Params:

• {GherkinDocument} ast - the AST needs to be processed
• {...DefaultConfig|Object} pre-compilers - the pre-compilers needs to be applied to the given AST

Returns: {GherkinDocument} the processed AST

format

Formats the given GherkinDocument to text. Equivalent of gherkin-assembler's format method. See API here.

Configuration

If you want to create own pre-compiler, you only have to extends the Default class and override the filter and/or event methods, that you want to use; or create and object with the desired methods.

Event methods

Every element can be modified by using it's correspondent event methods.

All event methods (except onFeature) receives the given element, it's parent and - if applicable - the index of the element. Given that all event receives the given element as an Object, those can be easily modified by modifying the object itself.

If you return

• null, then the given element will be deleted
• an element, then the original element will be replaced with the returned one
• an element array, in case of event which process list element (i.e. tag, scenario, examples, step, background, scenario outline), then the original element will be replaced with the returned list

The following methods are available, to see exact signature of the given method, click on the name of it:

• onFeature
• onScenario
• onBackground
• onScenarioOutline
• onStep
• onTag
• onDocString
• onDataTable
• onExamples
• onExampleHeader
• onExampleRow

Filter methods

Every element list in the AST can be filtered by using it's correspondent pre- or post filter methods. A pre filter methods is applied before the processing of the event, the post applied after it.

All filter methods receives the given element, it's parent and the index of the element. If the methods returns false the given element will be excluded from the final list, otherwise not.

The following methods are available, to see exact signature of the given method, click on the name of it:

• preFilterScenario, postFilterScenario
• preFilterTag, postFilterTag
• preFilterStep, postFilterStep
• preFilterRow, postFilterRow
• preFilterExamples, postFilterExamples

Changelog

(gherkin-precompiler) 1.0.0 - 2017-09-25

Added

• Add code to apply preprocessing rules to Gherkin feature files (#1)
• Add predefined precompilers: replacer (#2)