From 0f0b0628c1f9f4ce6d92f3ae258402e5547d2c17 Mon Sep 17 00:00:00 2001
From: Princi Vershwal <vershwal.princi@gmail.com>
Date: Tue, 17 Sep 2024 18:35:39 +0530
Subject: [PATCH] Added caching for checking partials  (#553)

Ref: https://linear.app/tryghost/issue/ENG-1444/gscan-slow-checking-for-themes-with-many-files#comment-62c7724a
---
 lib/checks/090-template-syntax.js | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/lib/checks/090-template-syntax.js b/lib/checks/090-template-syntax.js
index 38dd2e4f..2eed2049 100644
--- a/lib/checks/090-template-syntax.js
+++ b/lib/checks/090-template-syntax.js
@@ -3,7 +3,7 @@ const spec = require('../specs');
 const {versions, getPackageJSON} = require('../utils');
 const ASTLinter = require('../ast-linter');
 
-function processFileFunction(files, failures, rules) {
+function processFileFunction(files, failures, rules, partialVerificationCache) {
     // This rule is needed to find partials
     // Partials are needed for a full parsing
     if (!rules['mark-used-partials']) {
@@ -16,6 +16,16 @@ function processFileFunction(files, failures, rules) {
             return;
         }
 
+        const fileName = themeFile.file;
+
+        // Check if the file is a partial
+        const isPartial = fileName.startsWith('partials/');
+
+        // Skip if already cached (for partials only)
+        if (isPartial && partialVerificationCache.has(fileName)) {
+            return;
+        }
+
         const astResults = linter.verify({
             parsed: themeFile.parsed,
             rules,
@@ -30,6 +40,11 @@ function processFileFunction(files, failures, rules) {
             });
         }
 
+        // Cache the result for this partial
+        if (isPartial) {
+            partialVerificationCache.set(fileName, astResults);
+        }
+
         linter.partials.forEach(({normalizedName}) => {
             const file = files.find(f => f.normalizedFile === `partials/${normalizedName}.hbs`);
             if (file) {
@@ -62,15 +77,16 @@ const checkTemplateSyntax = function checkTemplateSyntax(theme, options) {
     });
 
     _.each(rulesToCheck, function (check, ruleCode) {
+        const partialVerificationCache = new Map();
         const failures = [];
         const processFile = processFileFunction(
             theme.files,
             failures,
             {
                 [ruleCode]: require(`../ast-linter/rules`)[ruleCode]
-            }
+            },
+            partialVerificationCache
         );
-
         const linter = new ASTLinter({
             partials: theme.partials,
             inlinePartials: [],