correct no-extraneous-dependencies rule: get the real name from the resolved package.json. If not aliased imports (alias/react for example) will not be correctly interpreted

Author: JEROMEH

Diff for: src/core/packagePath.js

@@ -1,12 +1,18 @@
 import {dirname} from 'path'
 import findUp from 'find-up'
+import readPkgUp from 'read-pkg-up'
 
 
 export function getContextPackagePath(context) {
   return getFilePackagePath(context.getFilename())
 }
 
 export function getFilePackagePath(filePath) {
-  const fp = findUp.sync('package.json', {cwd: filePath, normalize: false})
+  const fp = findUp.sync('package.json', {cwd: filePath})
   return dirname(fp)
 }
+
+export function getFilePackageName(filePath) {
+  const pkg = readPkgUp.sync({cwd: filePath, normalize: false}).pkg
+  return pkg && pkg.name
+}

Diff for: src/rules/no-extraneous-dependencies.js

@@ -4,6 +4,7 @@ import readPkgUp from 'read-pkg-up'
 import minimatch from 'minimatch'
 import resolve from 'eslint-module-utils/resolve'
 import importType from '../core/importType'
+import { getFilePackageName } from '../core/packagePath'
 import isStaticRequire from '../core/staticRequire'
 import docsUrl from '../docsUrl'
 
@@ -109,6 +110,17 @@ function optDepErrorMessage(packageName) {
     `not optionalDependencies.`
 }
 
+function getModuleOriginalName(name) {
+  const splitName = name.split('/')
+  return splitName[0][0] === '@'
+    ? splitName.slice(0, 2).join('/')
+    : splitName[0]
+}
+
+function getModuleRealName(resolved) {
+  return getFilePackageName(resolved)
+}
+
 function reportIfMissing(context, deps, depsOptions, node, name) {
   // Do not report when importing types
   if (node.importKind === 'type') {
@@ -122,10 +134,11 @@ function reportIfMissing(context, deps, depsOptions, node, name) {
   const resolved = resolve(name, context)
   if (!resolved) { return }
 
-  const splitName = name.split('/')
-  const packageName = splitName[0][0] === '@'
-    ? splitName.slice(0, 2).join('/')
-    : splitName[0]
+  // get the real name from the resolved package.json
+  // if not aliased imports (alias/react for example) will not be correctly interpreted
+  // fallback on original name in case no package.json found
+  const packageName = getModuleRealName(resolved) || getModuleOriginalName(name)
+
   const isInDeps = deps.dependencies[packageName] !== undefined
   const isInDevDeps = deps.devDependencies[packageName] !== undefined
   const isInOptDeps = deps.optionalDependencies[packageName] !== undefined

Diff for: tests/files/webpack.config.js

@@ -2,5 +2,8 @@ module.exports = {
   resolve: {
     extensions: ['', '.js', '.jsx'],
     root: __dirname,
+    alias: {
+      'alias/chai$': 'chai' // alias for no-extraneous-dependencies tests
+    }
   },
 }

Diff for: tests/src/rules/no-extraneous-dependencies.js

@@ -330,5 +330,14 @@ ruleTester.run('no-extraneous-dependencies', rule, {
         message: '\'not-a-dependency\' should be listed in the project\'s dependencies. Run \'npm i -S not-a-dependency\' to add it',
       }],
     }),
+    test({
+      code: 'import chai from "alias/chai";',
+      settings: { 'import/resolver': 'webpack' },
+      errors: [{
+        ruleId: 'no-extraneous-dependencies',
+        // missing dependency is chai not alias
+        message: "'chai' should be listed in the project's dependencies. Run 'npm i -S chai' to add it",
+      }],
+    }),
   ],
 })