From c01dff197faf16372f6b8c82edb72020678a1a16 Mon Sep 17 00:00:00 2001
From: Alexander Bocken <alexander@bocken.org>
Date: Thu, 23 Apr 2026 15:50:08 +0200
Subject: [PATCH] perf(recipes/search): memoise per-recipe normalized search
 string

Every keystroke the filter rebuilt the lowercased + diacritic-stripped
+ soft-hyphen-stripped concat of name/description/tags per recipe. For
a 200+ recipe catalogue that's a lot of regex work on the hot path.

Cache the normalised string in a WeakMap keyed by the recipe object;
first keystroke still pays the full cost, every subsequent one is a
single indexOf per recipe.

Picked client-side memoisation over the audit's suggested server-side
`_searchKey` to avoid duplicating every recipe's text over the wire.
---
 TODO.md                                  |  2 +-
 package.json                             |  2 +-
 src/lib/components/recipes/Search.svelte | 46 +++++++++++++++---------
 3 files changed, 31 insertions(+), 19 deletions(-)

diff --git a/TODO.md b/TODO.md
index 9df72f2b..01338a1d 100644
--- a/TODO.md
+++ b/TODO.md
@@ -14,7 +14,7 @@ Order = impact. Font items + app.html preload intentionally skipped.
 - [x] 8. Calendar payload trim — `yearDays` narrowed to `{iso, color}` (needle lookup only), new pre-filtered `feastDots` array carries feast-specific metadata. Also fixed a stray double `locals.session ?? (locals.session ?? …)` in both calendar page loaders.
 - [x] 9. History sessions endpoint — projection narrowed to exactly what SessionCard reads (drops notes, templates, mode, endTime, session-level gpsPreview); added `.lean()`.
 - [x] 10. `Cache-Control` headers: 8 h public on the shuffled recipe list endpoints (`all_brief`, `category/[c]`, `tag/[t]`, `icon/[i]`, `in_season/[m]`) — rand_array is seeded per UTC day, safe to share. 1 h public on distinct-value lists (`category`, `tag`, `icon`). 5 min public on recipe detail. `private 1h` on fitness `/exercises/filters`. Calendar page skipped (session serialised into layout HTML).
-- [ ] 11. Search — debounce 100 ms + server-side pre-normalized `_searchKey`
+- [x] 11. Search — debounce was already 100 ms. Instead of a server-side `_searchKey` (would duplicate text over the wire), memoise per-recipe normalized string in a `WeakMap` on the client — built lazily, reused across every subsequent keystroke.
 
 ## Features
 [x] on /fitness/measure, fill "Past measurements" in SSR only for the last 10 measurements. anything further should be fetched client side on mount to decreae initial page load time. use a "show more" button and paginate measurments.
diff --git a/package.json b/package.json
index 0811669e..de78de9c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "homepage",
-	"version": "1.46.24",
+	"version": "1.46.25",
 	"private": true,
 	"type": "module",
 	"scripts": {
diff --git a/src/lib/components/recipes/Search.svelte b/src/lib/components/recipes/Search.svelte
index 68fd3c81..b17bf190 100644
--- a/src/lib/components/recipes/Search.svelte
+++ b/src/lib/components/recipes/Search.svelte
@@ -122,6 +122,32 @@
         });
     }
 
+    /** @param {string} s */
+    function normalizeSearchText(s) {
+        return s.toLowerCase()
+            .normalize('NFD')
+            .replace(/\p{Diacritic}/gu, '')
+            .replace(/&shy;|­/g, '');
+    }
+
+    // Memoised normalized search string per recipe. Building it is the hot
+    // path (NFD + regex replace for every recipe × every keystroke), so we
+    // compute it once per recipe array and reuse across keystrokes. Shipping
+    // a pre-normalized `_searchKey` from the server would duplicate the text
+    // fields over the wire — this keeps the payload small and amortises the
+    // cost on the client instead.
+    /** @type {WeakMap<object, string>} */
+    const searchIndex = new WeakMap();
+    /** @param {any} recipe */
+    function searchStringFor(recipe) {
+        const cached = searchIndex.get(recipe);
+        if (cached !== undefined) return cached;
+        const raw = [recipe.name || '', recipe.description || '', ...(recipe.tags || [])].join(' ');
+        const norm = normalizeSearchText(raw);
+        searchIndex.set(recipe, norm);
+        return norm;
+    }
+
     // Perform search directly (no worker)
     /** @param {string} query */
     function performSearch(query) {
@@ -138,25 +164,11 @@
         }
 
         // Normalize and split search query
-        const searchText = query.toLowerCase().trim()
-            .normalize('NFD')
-            .replace(/\p{Diacritic}/gu, "");
-        const searchTerms = searchText.split(" ").filter((/** @type {string} */ term) => term.length > 0);
+        const searchText = normalizeSearchText(query.trim());
+        const searchTerms = searchText.split(' ').filter((/** @type {string} */ term) => term.length > 0);
 
-        // Filter recipes by text
         const matched = filteredByNonText.filter((/** @type {any} */ recipe) => {
-            // Build searchable string from recipe data
-            const searchString = [
-                recipe.name || '',
-                recipe.description || '',
-                ...(recipe.tags || [])
-            ].join(' ')
-                .toLowerCase()
-                .normalize('NFD')
-                .replace(/\p{Diacritic}/gu, "")
-                .replace(/&shy;|­/g, ''); // Remove soft hyphens
-
-            // All search terms must match
+            const searchString = searchStringFor(recipe);
             return searchTerms.every((/** @type {string} */ term) => searchString.includes(term));
         });