gherkin-lint/dist/rules/only-one-when.js

A Gherkin linter/validator written in javascript

"use strict";

const gherkinUtils = require('./utils/gherkin.js');

const rule = 'only-one-when';

function run(feature) {
  if (!feature) {
    return [];
  }

  let errors = [];

  function getScenarios(featureChildren) {
    let simpleScenarios = featureChildren.filter(child => child.scenario).map(child => child.scenario);
    let ruleScenarios = featureChildren.filter(child => child.rule).map(child => child.rule.children).reduce((flattened, element) => flattened.concat(element), []).filter(grandchild => grandchild.scenario).map(grandchild => grandchild.scenario);
    return simpleScenarios.concat(ruleScenarios);
  }

  let scenarios = getScenarios(feature.children);
  scenarios.forEach(scenario => {
    let lastRealKeyword = '';
    let whenCount = 0;
    let firstViolationLine = 0;
    scenario.steps.forEach(step => {
      let keyword = gherkinUtils.getLanguageInsitiveKeyword(step, feature.language);

      if (keyword === 'when' || keyword === 'and' && lastRealKeyword === 'when') {
        lastRealKeyword = 'when';
        whenCount++;

        if (whenCount > 1 && firstViolationLine === 0) {
          firstViolationLine = step.location.line;
        }
      } else {
        lastRealKeyword = keyword;
      }
    });

    if (whenCount > 1) {
      errors.push(createError(scenario, whenCount, firstViolationLine));
    }
  });
  return errors;
}

function createError(scenario, whenCount, lineNumber) {
  return {
    message: `Scenario "${scenario.name}" contains ${whenCount} When statements (max 1)`,
    rule: rule,
    line: lineNumber
  };
}

module.exports = {
  name: rule,
  run: run
};