From 9a04fc387679f34ef45ae29575ec8779684bb8d5 Mon Sep 17 00:00:00 2001
From: Luca Greco <luca.greco@alcacoop.it>
Date: Wed, 2 Nov 2016 21:45:02 +0100
Subject: [PATCH] fix: pluralize argument in raised error message

---
 browser-polyfill.in.js       | 6 ++++--
 test/test-async-functions.js | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/browser-polyfill.in.js b/browser-polyfill.in.js
index df26346..b7041e7 100644
--- a/browser-polyfill.in.js
+++ b/browser-polyfill.in.js
@@ -105,13 +105,15 @@ if (typeof browser === "undefined") {
      *       The generated wrapper function.
      */
     const wrapAsyncFunction = (name, metadata) => {
+      const pluralizeArguments = (numArgs) => numArgs == 1 ? "argument" : "arguments";
+
       return function asyncFunctionWrapper(target, ...args) {
         if (args.length < metadata.minArgs) {
-          throw new Error(`Expected at least ${metadata.minArgs} arguments for ${name}(), got ${args.length}`);
+          throw new Error(`Expected at least ${metadata.minArgs} ${pluralizeArguments(metadata.minArgs)} for ${name}(), got ${args.length}`);
         }
 
         if (args.length > metadata.maxArgs) {
-          throw new Error(`Expected at most ${metadata.maxArgs} arguments for ${name}(), got ${args.length}`);
+          throw new Error(`Expected at most ${metadata.maxArgs} ${pluralizeArguments(metadata.maxArgs)} for ${name}(), got ${args.length}`);
         }
 
         return new Promise((resolve, reject) => {
diff --git a/test/test-async-functions.js b/test/test-async-functions.js
index 5c8e8de..836163a 100644
--- a/test/test-async-functions.js
+++ b/test/test-async-functions.js
@@ -79,7 +79,7 @@ describe("browser-polyfill", () => {
       return setupTestDOMWindow(fakeChrome).then(window => {
         throws(() => {
           window.browser.runtime.sendMessage();
-        }, "Expected at least 1 arguments for sendMessage(), got 0");
+        }, "Expected at least 1 argument for sendMessage(), got 0");
 
         throws(() => {
           window.browser.runtime.sendMessage("0", "1", "2", "3");