elasticsearch-js/scripts/utils/generateDocs.js

// Licensed to Elasticsearch B.V under one or more agreements.
// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
// See the LICENSE file in the project root for more information

'use strict'

const dedent = require('dedent')

function generateDocs (common, spec) {
  var doc = dedent`
  [[api-reference]]
  == API Reference

  This document contains the entire list of the Elasticsearch API supported by the client, both OSS and commercial. The client is entirely licensed under Apache 2.0.

  Elasticsearch exposes an HTTP layer to communicate with, and the client is a library that will help you do this. Because of this reason, you will see HTTP related parameters, such as ${'`'}body${'`'} or ${'`'}headers${'`'}.

  Every API can accept two objects, the first contains all the parameters that will be sent to Elasticsearch, while the second includes the request specific parameters, such as timeouts, headers, and so on.
  In the first object, every parameter but the body will be sent via querystring or url parameter, depending on the API, and every unrecognized parameter will be sent as querystring.

  [source,js]
  ----
  // promise API
  const result = await client.search({
    index: 'my-index',
    from: 20,
    size: 10,
    body: { foo: 'bar' }
  }, {
    ignore: [404],
    maxRetries: 3
  })

  // calback API
  client.search({
    index: 'my-index',
    from: 20,
    size: 10,
    body: { foo: 'bar' }
  }, {
    ignore: [404],
    maxRetries: 3
  }, (err, result) => {
    if (err) console.log(err)
  })
  ----

  In this document, you will find the reference of every parameter accepted by the querystring or the url. If you also need to send the body, you can find the documentation of its format in the reference link that is present along with every endpoint.

  ////////

  This documentation is generated by running:
  node scripts/run.js --tag tagName
  or
  node scripts/run.js --branch branchName

  ////////\n\n`
  doc += commonParameters(common)
  spec.forEach(s => {
    doc += '\n' + generateApiDoc(s)
  })
  return doc
}

function commonParameters (spec) {
  var doc = dedent`
  === Common parameters
  Parameters that are accepted by all API endpoints.

  link:{ref}/common-options.html[Reference]
  [cols=2*]
  |===\n`
  Object.keys(spec.params).forEach(key => {
    const name = isSnakeCased(key) && key !== camelify(key)
      ? '`' + key + '` or `' + camelify(key) + '`'
      : '`' + key + '`'

    doc += dedent`
    |${name}
    |${'`' + spec.params[key].type + '`'} - ${spec.params[key].description}`
    if (spec.params[key].default) {
      doc += ` +
    _Default:_ ${'`' + spec.params[key].default + '`'}`
    }
    doc += '\n\n'
  })

  doc += dedent`
  |===
  `
  return doc
}

function generateApiDoc (spec) {
  const name = Object.keys(spec)[0]
  const documentationUrl = spec[name].documentation && spec[name].documentation.url
    ? fixLink(name, spec[name].documentation.url)
    : ''
  const params = []
  // url params
  const urlParts = spec[name].url.paths.reduce((acc, path) => {
    if (!path.parts) return acc
    for (const part in path.parts) {
      if (acc[part] != null) continue
      acc[part] = path.parts[part]
    }
    return acc
  }, {})
  if (urlParts) {
    Object.keys(urlParts).forEach(param => {
      params.push({
        name: param,
        type: getType(urlParts[param].type, urlParts[param].options),
        description: urlParts[param].description,
        default: urlParts[param].default,
        deprecated: !!urlParts[param].deprecated
      })
    })
  }

  // query params
  const urlParams = spec[name].params
  if (urlParams) {
    Object.keys(urlParams).forEach(param => {
      const duplicate = params.find(ele => ele.name === param)
      if (duplicate) return
      params.push({
        name: param,
        type: getType(urlParams[param].type, urlParams[param].options),
        description: urlParams[param].description,
        default: urlParams[param].default,
        deprecated: !!urlParams[param].deprecated
      })
    })
  }

  // body params
  const body = spec[name].body
  if (body) {
    params.push({
      name: 'body',
      type: 'object',
      description: body.description,
      default: body.default,
      deprecated: !!body.deprecated
    })
  }

  const codeParameters = params
    .reduce((acc, val) => {
      var code = `${val.name}: ${val.type},`
      acc += acc === ''
        ? code
        : '\n    ' + code

      return acc
    }, '')
    // remove last comma
    .slice(0, -1)

  const stability = spec[name].stability === 'stable'
    ? ''
    : `*Stability:* ${spec[name].stability}`

  var doc = dedent`
  === ${camelify(name)}
  ${stability}
  [source,ts]
  ----
  client.${camelify(name)}(${codeParameters.length > 0 ? `{\n    ${codeParameters}\n}` : ''})
  ----\n`
  if (documentationUrl) {
    doc += `link:${documentationUrl}[Reference]\n`
  }

  if (params.length !== 0) {
    doc += dedent`[cols=2*]
    |===\n`
    doc += params.reduce((acc, val) => {
      const name = isSnakeCased(val.name) && val.name !== camelify(val.name)
        ? '`' + val.name + '` or `' + camelify(val.name) + '`'
        : '`' + val.name + '`'
      acc += dedent`
      |${name}
      |${'`' + val.type.replace(/\|/g, '\\|') + '`'} - ${val.description}`
      if (val.default) {
        acc += ` +\n_Default:_ ${'`' + val.default + '`'}`
      }
      if (val.deprecated) {
        acc += ` +\n\nWARNING: This parameter has been deprecated.`
      }
      return acc + '\n\n'
    }, '')

    doc += dedent`
    |===
    `
  }
  doc += '\n'
  return doc
}

const LINK_OVERRIDES = {
  'license.delete': '{ref}/delete-license.html',
  'license.get': '{ref}/get-license.html',
  'license.get_basic_status': '{ref}/get-basic-status.html',
  'license.get_trial_status': '{ref}/get-trial-status.html',
  'license.post': '{ref}/update-license.html',
  'license.post_start_basic': '{ref}/start-basic.html',
  'license.post_start_trial': '{ref}/start-trial.html',
  'migration.deprecations': '{ref}/migration-api-deprecation.html',
  'monitoring.bulk': '{ref}/es-monitoring.html',
  'ingest.delete_pipeline': '{ref}/delete-pipeline-api.html',
  'ingest.get_pipeline': '{ref}/get-pipeline-api.html',
  'ingest.put_pipeline': '{ref}/put-pipeline-api.html',
  'ingest.simulate': '{ref}/simulate-pipeline-api.html',
  'ingest.processor_grok': '{ref}/grok-processor.html#grok-processor-rest-get'
}
// Fixes bad urls in the JSON spec
function fixLink (name, str) {
  /* In 6.x some API start with `xpack.` when in master they do not. We
   * can safely ignore that for link generation. */
  name = name.replace(/^xpack\./, '')
  const override = LINK_OVERRIDES[name]
  if (override) return override
  if (!str) return ''
  /* Replace references to the guide with the attribute {ref} because
   * the json files in the Elasticsearch repo are a bit of a mess. */
  str = str.replace(/^.+guide\/en\/elasticsearch\/reference\/[^/]+\/([^./]*\.html(?:#.+)?)$/, '{ref}/$1')
  str = str.replace(/frozen\.html/, 'freeze-index-api.html')
  str = str.replace(/ml-file-structure\.html/, 'ml-find-file-structure.html')
  str = str.replace(/security-api-get-user-privileges\.html/, 'security-api-get-privileges.html')

  return str
}

function getType (type, options) {
  switch (type) {
    case 'list':
      return 'string | string[]'
    case 'date':
    case 'time':
    case 'timeout':
      return 'string'
    case 'enum':
      return options.map(k => `'${k}'`).join(' | ')
    case 'int':
    case 'double':
    case 'long':
      return 'number'
    default:
      return type
  }
}

function camelify (str) {
  return str[0] === '_'
    ? '_' + str.slice(1).replace(/_([a-z])/g, k => k[1].toUpperCase())
    : str.replace(/_([a-z])/g, k => k[1].toUpperCase())
}

function isSnakeCased (str) {
  return !!~str.indexOf('_')
}

module.exports = generateDocs