🆙 update(rule) add option to no-unused-keys rule

Author: kazupon

docs/rules/no-unused-keys.md

@@ -74,14 +74,14 @@ i18n.t('hi')
 
 ## Options
 
-You can specify allowed directive-comments.
-
 ```json
 {
   "vue-i18n/no-unused-keys": ["error", {
+    "src": ["./src"],
     "extensions": [".js", ".vue"]
   }]
 }
 ```
 
+- `src`: specify the source codes directory to be able to lint. If you don't set any options, it set to `process.cwd()` as default.
 - `extenstions`: an array to allow specified lintable target file extention. If you don't set any options, it set to `.js` and` .vue` as default.

lib/rules/no-unused-keys.js

@@ -8,24 +8,73 @@ const jsonAstParse = require('json-to-ast')
 const jsonDiffPatch = require('jsondiffpatch').create({})
 const flatten = require('flat')
 const collectKeys = require('../utils/collect-keys')
-const { loadLocaleMessages } = require('../utils/index')
+const { UNEXPETECD_ERROR_LOCATION, loadLocaleMessages } = require('../utils/index')
 const debug = require('debug')('eslint-plugin-vue-i18n:no-unused-keys')
 
 let usedLocaleMessageKeys = null // used locale message keys
 let localeMessages = null // used locale messages
+let localeDir = null
 
 function findExistLocaleMessage (fullpath, localeMessages) {
   return localeMessages.find(message => message.fullpath === fullpath)
 }
 
-function getUnusedKeys (diffLocaleMessage) {
-  const unusedKeys = []
-  Object.keys(diffLocaleMessage).forEach(key => {
-    const value = diffLocaleMessage[key]
-    if (value && Array.isArray(value) && value.length === 1) {
-      unusedKeys.push(key)
-    }
-  })
+function extractJsonInfo (context, node) {
+  try {
+    const [str, filename] = node.comments
+    return [
+      Buffer.from(str.value, 'base64').toString(),
+      Buffer.from(filename.value, 'base64').toString()
+    ]
+  } catch (e) {
+    context.report({
+      loc: UNEXPETECD_ERROR_LOCATION,
+      message: e.message
+    })
+    return []
+  }
+}
+
+function generateJsonAst (context, json, filename) {
+  let ast = null
+
+  try {
+    ast = jsonAstParse(json, { loc: true, source: filename })
+  } catch (e) {
+    const { message, line, column } = e
+    context.report({
+      message,
+      loc: { line, column }
+    })
+  }
+
+  return ast
+}
+
+function getUnusedKeys (context, json, usedkeys) {
+  let unusedKeys = []
+
+  try {
+    const jsonValue = JSON.parse(json)
+    const diffValue = jsonDiffPatch.diff(
+      flatten(usedkeys, { safe: true }),
+      flatten(jsonValue, { safe: true })
+    )
+    const diffLocaleMessage = flatten(diffValue, { safe: true })
+    Object.keys(diffLocaleMessage).forEach(key => {
+      const value = diffLocaleMessage[key]
+      if (value && Array.isArray(value) && value.length === 1) {
+        unusedKeys.push(key)
+      }
+    })
+  } catch (e) {
+    context.report({
+      loc: UNEXPETECD_ERROR_LOCATION,
+      message: e.message
+    })
+    unusedKeys = null
+  }
+
   return unusedKeys
 }
 
@@ -65,53 +114,53 @@ function create (context) {
 
   const { settings } = context
   if (!settings['vue-i18n'] || !settings['vue-i18n'].localeDir) {
-    // TODO: should be error
+    context.report({
+      loc: UNEXPETECD_ERROR_LOCATION,
+      message: `You need to 'localeDir' at 'settings. See the 'eslint-plugin-vue-i18n documentation`
+    })
     return {}
   }
-  localeMessages = localeMessages || loadLocaleMessages(settings['vue-i18n'].localeDir)
+
+  if (localeDir !== settings['vue-i18n'].localeDir) {
+    debug(`change localeDir: ${localeDir} -> ${settings['vue-i18n'].localeDir}`)
+    localeDir = settings['vue-i18n'].localeDir
+    localeMessages = loadLocaleMessages(localeDir)
+  } else {
+    localeMessages = localeMessages || loadLocaleMessages(settings['vue-i18n'].localeDir)
+  }
 
   const targetLocaleMessage = findExistLocaleMessage(filename, localeMessages)
   if (!targetLocaleMessage) {
     debug(`ignore ${filename} in no-unused-keys`)
     return {}
   }
 
-  const { extensions } = (context.options && context.options[0]) || { extensions: ['.js', '.vue'] }
-  const src = [process.cwd()] || ['.']
+  const options = (context.options && context.options[0]) || {}
+  const src = options.src || process.cwd()
+  const extensions = options.extensions || ['.js', '.vue']
 
   if (!usedLocaleMessageKeys) {
-    usedLocaleMessageKeys = collectKeys(src, extensions)
+    usedLocaleMessageKeys = collectKeys([src], extensions)
   }
 
   return {
     Program (node) {
-      const [stringNode, filenameNode] = node.comments
-      const jsonString = Buffer.from(stringNode.value, 'base64').toString()
-      const jsonFilename = Buffer.from(filenameNode.value, 'base64').toString()
-      const jsonValue = JSON.parse(jsonString)
-      try {
-        const diffValue = jsonDiffPatch.diff(
-          flatten(usedLocaleMessageKeys, { safe: true }),
-          flatten(jsonValue, { safe: true })
-        )
-        const diffLocaleMessage = flatten(diffValue, { safe: true })
-        const unusedKeys = getUnusedKeys(diffLocaleMessage)
-
-        const jsonAstSettings = { loc: true, source: jsonFilename }
-        const ast = jsonAstParse(jsonString, jsonAstSettings)
-        traverseJsonAstWithUnusedKeys(unusedKeys, ast, (fullpath, node) => {
-          const { line, column } = node.loc.start
-          context.report({
-            message: `unused '${fullpath}' key in '${targetLocaleMessage.path}'`,
-            loc: { line, column }
-          })
-        })
-      } catch ({ message, line, column }) {
+      const [jsonString, jsonFilename] = extractJsonInfo(context, node)
+      if (!jsonString || !jsonFilename) { return }
+
+      const ast = generateJsonAst(context, jsonString, jsonFilename)
+      if (!ast) { return }
+
+      const unusedKeys = getUnusedKeys(context, jsonString, usedLocaleMessageKeys)
+      if (!unusedKeys) { return }
+
+      traverseJsonAstWithUnusedKeys(unusedKeys, ast, (fullpath, node) => {
+        const { line, column } = node.loc.start
         context.report({
-          message,
+          message: `unused '${fullpath}' key in '${targetLocaleMessage.path}'`,
           loc: { line, column }
         })
-      }
+      })
     }
   }
 }
@@ -128,6 +177,9 @@ module.exports = {
     schema: [{
       type: 'object',
       properties: {
+        src: {
+          type: 'string'
+        },
         extensions: {
           type: 'array',
           items: { type: 'string' },