From d56c6541c6dff9ae68267925ddd11e6590389a48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kat=20March=C3=A1n?= <kzm@sykosomatic.org>
Date: Fri, 16 Feb 2018 14:35:26 -0800
Subject: [PATCH] fix(integrityStream): dedupe algorithms to generate

---
 index.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/index.js b/index.js
index 43c1507..8527433 100644
--- a/index.js
+++ b/index.js
@@ -249,8 +249,12 @@ function integrityStream (opts) {
   const algorithm = goodSri && sri.pickAlgorithm(opts)
   const digests = goodSri && sri[algorithm]
   // Calculating stream
-  const algorithms = (opts.algorithms || ['sha512'])
-  .concat(algorithm ? [algorithm] : [])
+  const algorithms = Array.from(
+    new Set(
+      (opts.algorithms || ['sha512'])
+      .concat(algorithm ? [algorithm] : [])
+    )
+  )
   const hashes = algorithms.map(crypto.createHash)
   let streamSize = 0
   const stream = new Transform({