From 4d0256228d3a22a092f3467f6dd535b143ec8f8e Mon Sep 17 00:00:00 2001
From: paanSinghCoder <gaurav3017@gmail.com>
Date: Wed, 29 Apr 2026 09:22:18 +0530
Subject: [PATCH] fix(theme-provider): callback deps, inline script, and
 onThemeChange (#646)

- Correct setTheme deps to track storageKey instead of unused forcedTheme.
- Add missing enableSystem and applyTheme to handleMediaQuery deps.
- Fix inline-script generation in updateDOM: drop the `name + "|| ''"` concat
  that produced classList.add('') (throws) or setAttribute(n, '') (junk
  attribute) when a value-map lookup missed; guard the literal path with
  if(${val}) so the DOM call only runs when the lookup is truthy.
- Add onThemeChange prop. Fires on actual theme/resolvedTheme changes,
  skipping the initial mount. Uses a ref so the callback identity is read
  at fire time, decoupling effect cadence from consumer render churn.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 .../components/theme-provider/theme.tsx       | 37 ++++++++++++++++---
 .../components/theme-provider/types.ts        |  6 ++-
 2 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/packages/raystack/components/theme-provider/theme.tsx b/packages/raystack/components/theme-provider/theme.tsx
index ae9c2bf93..82dfc8ea1 100644
--- a/packages/raystack/components/theme-provider/theme.tsx
+++ b/packages/raystack/components/theme-provider/theme.tsx
@@ -8,6 +8,7 @@ import {
   useContext,
   useEffect,
   useMemo,
+  useRef,
   useState
 } from 'react';
 
@@ -47,7 +48,8 @@ const Theme = ({
   nonce,
   style = 'modern',
   accentColor = 'indigo',
-  grayColor = 'gray'
+  grayColor = 'gray',
+  onThemeChange
 }: ThemeProviderProps) => {
   const [theme, setThemeState] = useState(() =>
     getTheme(storageKey, defaultTheme)
@@ -124,7 +126,7 @@ const Theme = ({
         // Unsupported
       }
     },
-    [forcedTheme]
+    [storageKey]
   );
 
   const handleMediaQuery = useCallback(
@@ -136,7 +138,7 @@ const Theme = ({
         applyTheme('system');
       }
     },
-    [theme, forcedTheme]
+    [theme, forcedTheme, enableSystem, applyTheme]
   );
 
   // Always listen to System preference
@@ -171,6 +173,25 @@ const Theme = ({
     applyTheme(forcedTheme ?? theme);
   }, [forcedTheme, theme]);
 
+  // Fire onThemeChange on actual changes, skipping the initial mount.
+  // Ref keeps the latest callback without re-firing when consumers pass an inline function.
+  const onThemeChangeRef = useRef(onThemeChange);
+  useEffect(() => {
+    onThemeChangeRef.current = onThemeChange;
+  });
+  const themeChangeMounted = useRef(false);
+  useEffect(() => {
+    if (!themeChangeMounted.current) {
+      themeChangeMounted.current = true;
+      return;
+    }
+    if (theme) {
+      const resolved =
+        theme === 'system' && resolvedTheme ? resolvedTheme : theme;
+      onThemeChangeRef.current?.(theme, resolved);
+    }
+  }, [theme, resolvedTheme]);
+
   const providerValue = useMemo(
     () => ({
       theme,
@@ -277,7 +298,7 @@ const ThemeScript = memo(
       setColorScheme = true
     ) => {
       const resolvedName = value ? value[name] : name;
-      const val = literal ? name + `|| ''` : `'${resolvedName}'`;
+      const val = literal ? name : `'${resolvedName}'`;
       let text = '';
 
       // MUCH faster to set colorScheme alongside HTML attribute/class
@@ -293,13 +314,17 @@ const ThemeScript = memo(
       }
 
       if (attribute === 'class') {
-        if (literal || resolvedName) {
+        if (literal) {
+          text += `if(${val})c.add(${val})`;
+        } else if (resolvedName) {
           text += `c.add(${val})`;
         } else {
           text += `null`;
         }
       } else {
-        if (resolvedName) {
+        if (literal) {
+          text += `if(${val})d[s](n,${val})`;
+        } else if (resolvedName) {
           text += `d[s](n,${val})`;
         }
       }
diff --git a/packages/raystack/components/theme-provider/types.ts b/packages/raystack/components/theme-provider/types.ts
index 897aad606..12675a57b 100644
--- a/packages/raystack/components/theme-provider/types.ts
+++ b/packages/raystack/components/theme-provider/types.ts
@@ -14,7 +14,7 @@ export interface UseThemeProps {
   /** If `enableSystem` is true and the active theme is "system", this returns whether the system preference resolved to "dark" or "light". Otherwise, identical to `theme` */
   resolvedTheme?: string;
   /** If enableSystem is true, returns the System theme preference ("dark" or "light"), regardless what the active theme is */
-  systemTheme?: "dark" | "light";
+  systemTheme?: 'dark' | 'light';
 }
 
 export interface ThemeProviderProps {
@@ -33,7 +33,7 @@ export interface ThemeProviderProps {
   /** Default theme name (for v0.0.12 and lower the default was light). If `enableSystem` is false, the default theme is light */
   defaultTheme?: string;
   /** HTML attribute modified based on the active theme. Accepts `class` and `data-*` (meaning any data attribute, `data-mode`, `data-color`, etc.) */
-  attribute?: string | "class";
+  attribute?: string | 'class';
   /** Mapping of theme name to HTML attribute value. Object where key is the theme name and value is the attribute value */
   value?: ValueObject;
   /** Nonce string to pass to the inline script for CSP headers */
@@ -46,4 +46,6 @@ export interface ThemeProviderProps {
   accentColor?: 'indigo' | 'orange' | 'mint';
   /** Gray color variant for the theme, options are 'gray', 'mauve', or 'slate' */
   grayColor?: 'gray' | 'mauve' | 'slate';
+  /** Called when the active theme changes. `resolvedTheme` is the actual applied theme (`'light'`/`'dark'` when `theme` is `'system'`). Not fired on initial mount. */
+  onThemeChange?: (theme: string, resolvedTheme: string) => void;
 }