From 1ca355a560e1d445c831f9c01d54440ac74016da Mon Sep 17 00:00:00 2001
From: Farnabaz <farnabaz@gmail.com>
Date: Wed, 28 Oct 2026 12:10:34 +0100
Subject: [PATCH] chore: remove obsolete rehypeAnimate name workaround

Follow-up to #702.

Before #702 the processor cache keyed plugins by `fn.name`, so `createAnimatePlugin` renamed each `rehypeAnimate` closure to `rehypeAnimate$<n>` to avoid cache collisions. The cache now keys plugins by function identity (`getPluginId`), so each closure already gets its own key. This removes the `instanceId` counter and the `Object.defineProperty` override. The returned plugin object stays the same.

Also:
- Extends the unreleased `quiet-plugins-render` changeset with a note on the behavior change: plugin functions created during render now produce a new processor on each render. Create them once (module scope or `useMemo`) to keep cache hits.
- Adds a patch changeset for this cleanup.
---
 .changeset/plain-animate-name.md   | 5 +++++
 .changeset/quiet-plugins-render.md | 2 +-
 packages/streamdown/lib/animate.ts | 7 -------
 3 files changed, 6 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/plain-animate-name.md

diff --git a/.changeset/plain-animate-name.md b/.changeset/plain-animate-name.md
new file mode 100644
index 00000000..c826ff09
--- /dev/null
+++ b/.changeset/plain-animate-name.md
@@ -0,0 +1,5 @@
+---
+"streamdown": patch
+---
+
+Remove the obsolete rehypeAnimate name override; processor caching now uses function identity.
diff --git a/.changeset/quiet-plugins-render.md b/.changeset/quiet-plugins-render.md
index 5ada25f2..7d28c5ec 100644
--- a/.changeset/quiet-plugins-render.md
+++ b/.changeset/quiet-plugins-render.md
@@ -2,4 +2,4 @@
 "streamdown": patch
 ---
 
-Distinguish remark and rehype plugins by function identity when caching processors, so same-name plugins with different closures do not reuse each other's behavior.
+Distinguish remark and rehype plugins by function identity when caching processors, so same-name plugins with different closures do not reuse each other's behavior. Apps that create plugin functions during render now get a new processor on each render. This is slower for that pattern but does not grow memory; create plugins once (module scope or `useMemo`) to keep cache hits.
diff --git a/packages/streamdown/lib/animate.ts b/packages/streamdown/lib/animate.ts
index 642a2566..ac80861b 100644
--- a/packages/streamdown/lib/animate.ts
+++ b/packages/streamdown/lib/animate.ts
@@ -590,8 +590,6 @@ const processTextNode = (
   return index + nodes.length;
 };
 
-let instanceId = 0;
-
 /**
  * Create an animate rehype plugin. The optional `timeline` is an internal
  * Streamdown wiring detail — not part of the public `animated` prop surface.
@@ -636,7 +634,6 @@ function buildAnimatePlugin(
     pendingMark: null,
   };
 
-  const id = instanceId++;
   const rehypeAnimate = () => (tree: Root) => {
     const charCounter = { count: 0, newIndex: 0 };
 
@@ -692,10 +689,6 @@ function buildAnimatePlugin(
     renderState.prevContentLength = 0;
   };
 
-  Object.defineProperty(rehypeAnimate, "name", {
-    value: `rehypeAnimate$${id}`,
-  });
-
   return {
     name: "animate",
     type: "animate",