Add devCheck to localpack

Author: ehmicky

gulp/utils/localpack-code/dev_checks/index.js

@@ -0,0 +1,5 @@
+'use strict'
+
+module.exports = {
+  ...require('./main'),
+}

gulp/utils/localpack-code/dev_checks/main.js

@@ -0,0 +1,59 @@
+'use strict'
+
+const { mkdir, readFileSync, writeFile } = require('fs')
+const { promisify } = require('util')
+
+const { addScopeDirs } = require('./scope')
+
+const TEMPLATE = readFileSync(`${__dirname}/template.js`, { encoding: 'utf-8' })
+
+const pMkdir = promisify(mkdir)
+const pWriteFile = promisify(writeFile)
+
+// Add `{output}/node_modules/{file}.js` for each devDependency.
+// The file simply throws an error.
+// The goal is to check that the published module does not use devDependencies.
+// Without create dummy `node_modules`, it would require `packageRoot`
+// devDependencies, which are probably installed since they are needed for
+// testing itself.
+const addDevChecks = async function({ output }) {
+  const nodeModules = await getNodeModules({ output })
+
+  const devDependencies = getDevDependencies({ output })
+
+  await addScopeDirs({ devDependencies, nodeModules })
+
+  await Promise.all(
+    devDependencies.map(name => addDevCheck({ name, nodeModules })),
+  )
+}
+
+// Retrieve `{output}/node_modules`
+const getNodeModules = async function({ output }) {
+  const nodeModules = `${output}/node_modules`
+
+  await pMkdir(nodeModules)
+
+  return nodeModules
+}
+
+// Retrieve all `devDependencies` names.
+const getDevDependencies = function({ output }) {
+  // eslint-disable-next-line import/no-dynamic-require
+  const { devDependencies = {} } = require(`${output}/package.json`)
+  const devDependenciesA = Object.keys(devDependencies)
+  return devDependenciesA
+}
+
+// Add the dependency file, based on a simple template file.
+const addDevCheck = async function({ name, nodeModules }) {
+  const devCheckFile = `${nodeModules}/${name}.js`
+  const content = TEMPLATE.replace(TEMPLATE_TOKEN, name)
+  await pWriteFile(devCheckFile, content, { encoding: 'utf-8' })
+}
+
+const TEMPLATE_TOKEN = 'DEPENDENCY'
+
+module.exports = {
+  addDevChecks,
+}

gulp/utils/localpack-code/dev_checks/scope.js

@@ -0,0 +1,37 @@
+'use strict'
+
+const { mkdir } = require('fs')
+const { promisify } = require('util')
+
+const { uniq } = require('../utils')
+
+const pMkdir = promisify(mkdir)
+
+// Package with a scope (`@scope/name`) should be installed within `@scope`,
+// which we must create
+const addScopeDirs = async function({ devDependencies, nodeModules }) {
+  const scopeDirs = getScopeDirs({ devDependencies })
+
+  await Promise.all(
+    scopeDirs.map(scopeDir => pMkdir(`${nodeModules}/${scopeDir}`)),
+  )
+}
+
+// Retrieve all scopes
+const getScopeDirs = function({ devDependencies }) {
+  const scopes = devDependencies.filter(hasScope).map(getScope)
+  const scopesA = uniq(scopes)
+  return scopesA
+}
+
+const hasScope = function(name) {
+  return name.includes('/')
+}
+
+const getScope = function(name) {
+  return name.split('/')[0]
+}
+
+module.exports = {
+  addScopeDirs,
+}

gulp/utils/localpack-code/dev_checks/template.js

@@ -0,0 +1,3 @@
+'use strict'
+
+throw new Error("Cannot require 'DEPENDENCY' because it is a devDependency")

gulp/utils/localpack-code/main.js

@@ -14,6 +14,7 @@ const pRename = promisify(rename)
 
 const { getPackageRoot } = require('./root')
 const { getTempDir, cleanTempDir } = require('./temp')
+const { addDevChecks } = require('./dev_checks')
 
 // Runs `npm pack` then unpack it to `opts.output`
 const localpack = async function({ output } = {}) {
@@ -26,6 +27,8 @@ const localpack = async function({ output } = {}) {
 
   await unpack({ packageRoot, tempDir, output: outputA })
 
+  await addDevChecks({ output: outputA })
+
   await cleanTempDir({ tempDir })
 }
 

gulp/utils/localpack-code/utils.js

@@ -8,6 +8,16 @@ const omitBy = function(object, condition) {
   return Object.assign({}, ...pairs)
 }
 
+// Like Lodash uniq()
+const uniq = function(arr) {
+  return arr.filter(isUnique)
+}
+
+const isUnique = function(value, index, arr) {
+  return arr.slice(0, index).every(valueA => value !== valueA)
+}
+
 module.exports = {
   omitBy,
+  uniq,
 }