yarn: Use viewOne and viewMany from npm adapter.

Author: raineorshine

lib/package-managers/npm.js

@@ -346,5 +346,7 @@ module.exports = {
   },
 
   defaultPrefix,
-  packageAuthorChanged
+  packageAuthorChanged,
+  viewOne,
+  viewMany,
 }

lib/package-managers/yarn.js

@@ -2,17 +2,14 @@
 
 // eslint-disable-next-line fp/no-events
 const { once } = require('events')
-
 const _ = require('lodash')
 const cint = require('cint')
 const semver = require('semver')
 const spawn = require('spawn-please')
-const pacote = require('pacote')
 const libnpmconfig = require('libnpmconfig')
-
 const jsonlines = require('jsonlines')
-
 const versionUtil = require('../version-util')
+const { viewOne, viewMany } = require('./npm.js')
 
 const TIME_FIELDS = ['modified', 'created']
 
@@ -75,44 +72,6 @@ async function parseJsonLines(result) {
 
 }
 
-/**
- * Returns the value of one of the properties retrieved by yarn view.
- *
- * @param packageName   Name of the package
- * @param field         Field such as "versions" or "dist-tags.latest" are parsed from the pacote result (https://www.yarnjs.com/package/pacote#packument)
- * @param currentVersion
- * @returns            Promised result
- */
-async function viewOne(packageName, field, currentVersion, { timeout } = {}) {
-  const result = await viewMany(packageName, [field], currentVersion, { timeout })
-  return result && result[field]
-}
-
-/**
- * Returns an object of specified values retrieved by yarn view.
- *
- * @param packageName   Name of the package
- * @param fields      Array of fields like versions, time, version
- * @param currentVersion
- * @returns            Promised result
- */
-async function viewMany(packageName, fields, currentVersion, { timeout } = {}) {
-  if (currentVersion && (!semver.validRange(currentVersion) ||
-    versionUtil.isWildCard(currentVersion))) {
-    return Promise.resolve({})
-  }
-
-  yarnConfig.fullMetadata = fields.includes('time')
-
-  const result = await pacote.packument(packageName, { ...yarnConfig, timeout })
-  return fields.reduce((accum, field) => ({
-    ...accum,
-    [field]: field.startsWith('dist-tags.') && result.versions ?
-      result.versions[_.get(result, field)] :
-      result[field],
-  }), {})
-}
-
 /**
  * @param versions  Array of all available versions
  * @param pre     Enabled prerelease?