diff --git a/.changeset/clean-server-component-hydration.md b/.changeset/clean-server-component-hydration.md
new file mode 100644
index 0000000..7d3c0b6
--- /dev/null
+++ b/.changeset/clean-server-component-hydration.md
@@ -0,0 +1,5 @@
+---
+'vite-plugin-solid': patch
+---
+
+Prevent generated server-component hydration from shifting the `` structure. The bootstrap now runs at the start of the existing hydration script instead of adding an unexpected first child to ``.
diff --git a/examples/turnkey/test/run.mjs b/examples/turnkey/test/run.mjs
index 91ffa56..471f6fd 100644
--- a/examples/turnkey/test/run.mjs
+++ b/examples/turnkey/test/run.mjs
@@ -1433,19 +1433,22 @@ async function runFramesChecks(mode, origin) {
html.split(`${FRAMES_SECRET}-one`).length === 2,
);
record(mode, 'document', 't=0 slot records shipped (sc:slot)', html.includes('sc:slot:'));
- // Presence is not enough: the render plugin serializes a placeholder as
- // `self._$SC.r(id)`, so the registry must be defined BEFORE the hydration
- // data script runs. Anchoring the injection on `` put it after
- // , and any document whose payload carried a frame ref
- // threw "Cannot read properties of undefined (reading 'r')" — killing
- // hydration, so nothing in the page was interactive.
+ // Presence is not enough: the bootstrap must run before hydration data,
+ // but adding a separate script before the document's declared head nodes
+ // shifts Solid's structural hydration cursor. It belongs at the front of
+ // the existing HydrationScript instead.
const scBootstrapAt = html.indexOf('self._$SC=');
+ const hydrationRuntimeAt = html.indexOf('window._$HY');
const hydrationDataAt = html.indexOf('_$HY.r[');
record(
mode,
'document',
- 'SC bootstrap inline in head, before the hydration data script',
- scBootstrapAt !== -1 && (hydrationDataAt === -1 || scBootstrapAt < hydrationDataAt),
+ 'SC bootstrap starts the hydration script before hydration data',
+ scBootstrapAt !== -1 &&
+ hydrationRuntimeAt > scBootstrapAt &&
+ html.lastIndexOf(', before the hydration data script streams in — see
- // the transform below). Authored entries inject it themselves.
+ // placeholder registry the render plugin references; must start the
+ // hydration runtime script, before hydration data streams in — see the
+ // transform below). Authored entries inject it themselves.
const injectComponentBootstrap = generated && serverComponents;
const lines = [
@@ -419,17 +419,16 @@ export function ssrServe(
// placeholder as `self._$SC.r(id)`, so a document whose payload carries
// one throws on that reference if the registry is not defined yet.
// sits inside , so anchoring on ``
- // always lands after it — the opening tag is the only anchor that is
- // reliably before it.
+ // always lands after it. Prepend the bootstrap to that existing script
+ // so it runs first without adding a node that shifts hydration.
lines.push(
` if (!bootstrapped) {`,
- ` const headOpen = /]*)?>/.exec(chunk);`,
- ` if (headOpen) {`,
+ ` const at = chunk.indexOf('window._$HY');`,
+ ` if (at !== -1) {`,
` bootstrapped = true;`,
- ` const at = headOpen.index + headOpen[0].length;`,
` chunk =`,
` chunk.slice(0, at) +`,
- ` '