详解构建可运行的JavaScript规范的方法

const dependency = require('./dependency')module.exports = `

  Example of a Specification File

  This project allows to test JavaScript programs using specification files.

  Every *.spec.js file exports a single template literal that includes a general

  explanation of the file being specified. Each file represents a logical

  component of a bigger system. Each logical component is composed of several

  units of functionality that can be tested for certain properties.

  Each one of this units of functionality may have one or more

  assertions. Each assertion is denoted by a line as the following:

  |- ${dependency} The dependency has been loaded and the first assert has

  been evaluated.

  Multiple assertions can be made for each file:

  |- ${false} This assertion will fail.

  |- ${2 + 2 === 4} This assertion will succeed.

  The combination of | and - will form a Turnstile ligature (|-) using the appropriate

  font. Fira Code is recommended. A Turnstile symbol was used by Gottlob Frege

  at the start of sentenses being asserted as true.

  The intended usage is for specification-first software. Where the programmer

  defines the high level structure of a program in terms of a specification,

  then progressively builds the parts conforming that specification until all

  the tests are passed. A desired side-effect is having a simple way to generate

  up-to-date documentation outside the code for API consumers.

`

#!/usr/bin/env node

const fs = require('fs')

const path = require('path')

const specRegExp = /\.spec\.js$/

const target = path.join(process.cwd(), process.argv[2])

// Get all the specification file paths

// If a specification file is provided then just test that file

// Otherwise find all the specification files in the target directory

const paths = specRegExp.test(target)

  ? [ target ]

  : findSpecifications(target, specRegExp).filter(x => x)

// Get the content of each specification file

// Get the assertions of each specification file

const assertionGroups = getAssertions(getSpecifications(paths))

// Log all the assertions

logAssertions(assertionGroups)

// Check for any failed assertions and return an appropriate exit code

process.exitCode = checkAssertions(assertionGroups)

assertionGroup[specification][assertion]

function findSpecifications (dir, matchPattern) {

  return fs.readdirSync(dir)

    .map(filePath => path.join(dir, filePath))

    .filter(filePath => matchPattern.test(filePath) && fs.statSync(filePath).isFile())

}

function getSpecifications (paths) {

  return paths.map(path => require(path))

}

function getAssertions (specifications) {

  return specifications.map(specification => ({

    title: specification.split('\n\n', 1)[0].trim(),

    assertions: specification.match(/^( |\t)*(\|-)(.|\n)*?\./gm).map(assertion => {

      const assertionFragments = /(?:\|-) (\w*) ((?:.|\n)*)/.exec(assertion)

      return {

        value: assertionFragments[1],

        description: assertionFragments[2].replace(/\n /, '')

      }

    })

  }))

}

title: <String: Name of this particular specification>,

  assertions: [

    {

      value: <Boolean: The result of the assertion>,

      description: <String: The short description for the assertion>

    }

  ]

}

{

  function logAssertions(assertionGroups) {

  // Methods to log text with colors

  const ansiColor = {

    blue: text => console.log(`\x1b[1m\x1b[34m${text}\x1b[39m\x1b[22m`),

    green: text => console.log(`\x1b[32m    ${text}\x1b[39m`),

    red: text => console.log(`\x1b[31m    ${text}\x1b[39m`)

  }

  // Log the results

  assertionGroups.forEach(group => {

    ansiColor.blue(group.title)

    group.assertions.forEach(assertion => {

      assertion.value === 'true'

        ? ansiColor.green(assertion.description)

        : ansiColor.red(assertion.description)

    })

  })

  console.log('\n')

}

function checkAssertions (assertionGroups) {

  return assertionGroups.some(

    group => group.assertions.some(assertion => assertion.value === 'false')

  ) ? 1 : 0

}

"scripts": {

  "test": "node index.js test"

  }