From 9f26e639dd6ddc9416bfd4d12b87efdac2699b1d Mon Sep 17 00:00:00 2001
From: Aaron O'Mullan <aaron.omullan@gmail.com>
Date: Tue, 13 Apr 2021 02:45:57 +0200
Subject: [PATCH] perf(fetch): optimize normalizeMethod() (#10154)

---
 op_crates/fetch/26_fetch.js | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/op_crates/fetch/26_fetch.js b/op_crates/fetch/26_fetch.js
index 8dc7c2056c..0bcd8f85ca 100644
--- a/op_crates/fetch/26_fetch.js
+++ b/op_crates/fetch/26_fetch.js
@@ -922,22 +922,36 @@
     });
   }
 
+  /**
+   * @param {string} m
+   * @returns {boolean}
+   */
+  function isKnownMethod(m) {
+    return (
+      m === "DELETE" ||
+      m === "GET" ||
+      m === "HEAD" ||
+      m === "OPTIONS" ||
+      m === "POST" ||
+      m === "PUT"
+    );
+  }
+
   /**
    * @param {string} m
    * @returns {string}
    */
   function normalizeMethod(m) {
+    // Fast path for already valid methods
+    if (isKnownMethod(m)) {
+      return m;
+    }
+    // Normalize lower case (slowpath and should be avoided ...)
     const u = byteUpperCase(m);
-    if (
-      u === "DELETE" ||
-      u === "GET" ||
-      u === "HEAD" ||
-      u === "OPTIONS" ||
-      u === "POST" ||
-      u === "PUT"
-    ) {
+    if (isKnownMethod(u)) {
       return u;
     }
+    // Otherwise passthrough
     return m;
   }