From e13dbd04f499623b0f48415bb43459ee9cd0d040 Mon Sep 17 00:00:00 2001
From: Matt Weber <1062734+mweberxyz@users.noreply.github.com>
Date: Mon, 26 Feb 2024 19:35:46 -0500
Subject: [PATCH] perf: cache layout access check

---
 index.js                | 16 +++++++++++++---
 test/test-handlebars.js |  7 ++++++-
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/index.js b/index.js
index 8b2b67e..ad01505 100644
--- a/index.js
+++ b/index.js
@@ -645,13 +645,23 @@ async function fastifyView (fastify, opts) {
   }
 
   function hasAccessToLayoutFile (fileName, ext) {
+    const layoutKey = `layout-${fileName}-${ext}`
+    let result = fastify[viewCache].get(layoutKey)
+
+    if (typeof result === 'boolean') {
+      return result
+    }
+
     try {
       accessSync(join(templatesDir, getPage(fileName, ext)))
-
-      return true
+      result = true
     } catch (e) {
-      return false
+      result = false
     }
+
+    fastify[viewCache].set(layoutKey, result)
+
+    return result
   }
 }
 
diff --git a/test/test-handlebars.js b/test/test-handlebars.js
index c49374f..d4e5999 100644
--- a/test/test-handlebars.js
+++ b/test/test-handlebars.js
@@ -331,7 +331,7 @@ test('fastify.view with handlebars engine with layout option on render', t => {
 })
 
 test('fastify.view with handlebars engine with invalid layout option on render should throw', t => {
-  t.plan(3)
+  t.plan(5)
 
   const fastify = Fastify()
   const handlebars = require('handlebars')
@@ -349,6 +349,11 @@ test('fastify.view with handlebars engine with invalid layout option on render s
       t.ok(err instanceof Error)
       t.equal(err.message, 'unable to access template "./templates/invalid-layout.hbs"')
     })
+    // repeated for test coverage of layout access check lru
+    fastify.view('./templates/index-for-layout.hbs', data, { layout: './templates/invalid-layout.hbs' }, (err, compiled) => {
+      t.ok(err instanceof Error)
+      t.equal(err.message, 'unable to access template "./templates/invalid-layout.hbs"')
+    })
   })
 })