fix: translation not working when using __ with a single parameter (#…

…1183)

.gitignore

@@ -5,3 +5,4 @@ node_modules/
 test.js
 coverage
 package-lock.json
+.npmrc

lib/validation.js

@@ -292,7 +292,7 @@ module.exports = function validation (yargs, usage, y18n) {
           // we default keys to 'undefined' that have been configured, we should not
           // apply conflicting check unless they are a value other than 'undefined'.
           if (value && argv[key] !== undefined && argv[value] !== undefined) {
-            usage.fail(__(`Arguments ${key} and ${value} are mutually exclusive`))
+            usage.fail(__('Arguments %s and %s are mutually exclusive', key, value))
           }
         })
       }

locales/pirate.json

@@ -8,5 +8,6 @@
     "other": "Ye be havin' to set the followin' arguments land lubber: %s"
   },
   "Show help": "Parlay this here code of conduct",
-  "Show version number": "'Tis the version ye be askin' fer"
+  "Show version number": "'Tis the version ye be askin' fer",
+  "Arguments %s and %s are mutually exclusive" : "Yon scurvy dogs %s and %s be as bad as rum and a prudish wench"
 }

test/validation.js

@@ -3,7 +3,7 @@
 
 const checkUsage = require('./helpers/utils').checkOutput
 const expect = require('chai').expect
-const yargs = require('../')
+let yargs = require('../')
 
 require('chai').should()
 
@@ -285,6 +285,28 @@ describe('validation tests', () => {
         })
         .parse()
     })
+
+    function loadLocale (locale) {
+      delete require.cache[require.resolve('../')]
+      delete require.cache[require.resolve('os-locale')]
+      yargs = require('../')
+      process.env.LC_ALL = locale
+    }
+
+    it('should use appropriate translation', done => {
+      loadLocale('pirate')
+      try {
+        yargs(['-f', '-b'])
+          .conflicts('f', 'b')
+          .fail(msg => {
+            msg.should.equal('Yon scurvy dogs f and b be as bad as rum and a prudish wench')
+            return done()
+          })
+          .parse()
+      } finally {
+        loadLocale('en_US.UTF-8')
+      }
+    })
   })
 
   describe('demand', () => {