From 8b75ce678620c672330b6f3affc13ae123fcc43e Mon Sep 17 00:00:00 2001
From: Sylvain Dumont <sylvain.dumont35@gmail.com>
Date: Tue, 10 Jul 2018 16:58:17 +0200
Subject: [PATCH] Allow full WebP alphaQuality range of 0-100 (#1290)

---
 lib/output.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/output.js b/lib/output.js
index cecdcde9..5e4a1c7b 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -271,10 +271,10 @@ function webp (options) {
     }
   }
   if (is.object(options) && is.defined(options.alphaQuality)) {
-    if (is.integer(options.alphaQuality) && is.inRange(options.alphaQuality, 1, 100)) {
+    if (is.integer(options.alphaQuality) && is.inRange(options.alphaQuality, 0, 100)) {
       this.options.webpAlphaQuality = options.alphaQuality;
     } else {
-      throw new Error('Invalid webp alpha quality (integer, 1-100) ' + options.alphaQuality);
+      throw new Error('Invalid webp alpha quality (integer, 0-100) ' + options.alphaQuality);
     }
   }
   if (is.object(options) && is.defined(options.lossless)) {