Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@packages/react/src/helmet.ts`:
- Around line 99-104: The current check in helmet.ts that sets inner content for
TagsWithInnerContent uses "&& data.children", which incorrectly drops falsy but
valid values like 0 and ''; change the presence test to check for null/undefined
(e.g., data.children != null or typeof data.children !== 'undefined') so values
like 0 and empty string are preserved, then keep the existing logic that sets
contentKey (script -> innerHTML else textContent) and converts arrays via
Array.isArray(data.children). Ensure you update the conditional around
TagsWithInnerContent.has(tagName) to use this null/undefined check so valid
falsy children are not lost.
- Around line 150-166: options.onRendered currently ignores the render context
and always calls cb(state, {}, {}); change options.onRendered to accept the
render context (the renders array of DomRenderTagContext) and compute addedTags
and removedTags by iterating renders (use the DomRenderTagContext properties to
group tags by tag type and collect added vs removed entries), then call
onChangeClientStateRef.current with cb(state, addedTags, removedTags). Update
the implementation referenced by options.onRendered and use the existing
onChangeClientStateRef and the title/meta/link/script/style/base logic to build
the state while deriving and supplying the real added/removed tag maps instead
of empty objects.
- Around line 149-173: The onRendered handler is only being attached when
onChangeClientStateRef.current is truthy on first effect run; change this by
always assigning options.onRendered = () => { const cb =
onChangeClientStateRef.current; if (!cb) return; /* build state, collect tags,
call cb(state, {}, {}) */ } (i.e. move the assignment outside the if guard),
keeping the internal check for cb so the latest prop is used; leave
headRef.current = head.push(getHeadChanges(), options) and the cleanup
(headRef.current?.dispose()) as-is so the callback registers even if the prop is
added later.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@docs/0.react/head/guides/0.get-started/migrate-from-react-helmet.md`:
- Around line 79-80: The fragment link in the migration note
("#_4-update-server-rendering") is incorrect and points to a dead anchor; update
the fragment to match the actual heading slug for the "Update Server Rendering"
section (e.g. replace "#_4-update-server-rendering" with the correct slug
generated from the heading text, such as "#update-server-rendering" or the exact
slug used below) so the note pointing to UnheadProvider correctly jumps to the
"Update Server Rendering" heading.

In `@packages/react/src/helmet.ts`:
- Around line 175-185: The onChangeClientState payload built in helmet.ts
currently uses keys like baseTags and lacks react-helmet fields (baseTag,
bodyAttributes, htmlAttributes, noscriptTags), so update the payload
construction (the block that builds state using titleEl and the loop over
['meta','link','script','style','base']) to produce a react-helmet-compatible
shape: include title, metaTags, linkTags, scriptTags, styleTags, baseTag
(singular, normalized from the head base element(s)), noscriptTags, and add
bodyAttributes and htmlAttributes (populated from document.body and
document.documentElement respectively); then call cb(state, {}, {}) as before so
consumers expecting react-helmet names receive the correct fields. Ensure you
reference the same variables (titleEl, the tag loop, and cb) when making these
key/name changes.
- Around line 169-193: The Helmet component currently calls
head.push(getHeadChanges(), options) inside useEffect (symbols: useEffect,
head.push, getHeadChanges, headRef, onChangeClientStateRef), which prevents SSR
registration; move the head.push(getHeadChanges(), options) call out of the
useEffect so it runs during render (assign the returned entry to headRef.current
during render), and keep the useEffect only to wire the client-side onRendered
callback and to dispose/reset headRef.current on unmount (use
onChangeClientStateRef inside the effect for callback wiring and call
headRef.current?.dispose() in the cleanup).

In `@packages/react/test/helmet.test.tsx`:
- Around line 259-264: The test destructures an unused "container" from the call
to render in the Helmet test; remove the unused binding by calling render(...)
directly (or assign its return to an underscore/ignored variable) so the render
result isn't destructured into an unused "container" variable; update the line
that currently reads const { container } = render(...) to simply call
render(...) while keeping the Helmet element and assertions unchanged.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@packages/react/src/helmet.ts`:
- Around line 113-116: The code derives tagName from the raw JSX element type
(variable tagName) and checks it against ValidHeadTags, but common patterns like
<html> and <body> are not canonicalized and therefore get skipped; update the
normalization logic in helmet.ts (where tagName is computed) to map 'html' ->
'htmlAttrs' and 'body' -> 'bodyAttrs' before calling ValidHeadTags.has(tagName)
so those elements are recognized; keep the rest of the validation flow unchanged
and only perform this string mapping immediately after computing tagName.

---

Duplicate comments:
In `@packages/react/src/helmet.ts`:
- Around line 175-185: The state object built for onChangeClientState is missing
noscriptTags, htmlAttributes, and bodyAttributes, and it incorrectly uses
baseTags (plural); update the construction around titleEl/state and the tag loop
so it builds keys exactly like react-helmet expects: metaTags, linkTags,
scriptTags, styleTags, baseTag (singular), noscriptTags, plus htmlAttributes and
bodyAttributes; collect htmlAttributes from document.documentElement.attributes,
bodyAttributes from document.body.attributes, and noscriptTags from head
noscript nodes, and pass that complete state into cb(state, {}, {}) so
onChangeClientState receives the full react-helmet-compatible newState.
- Around line 169-188: The component currently calls head.push(...) only inside
useEffect, so no entry is registered during render/SSR; to fix, call
head.push(getHeadChanges(), optionsWithoutOnRendered) synchronously during
render (store the returned entry in headRef.current) so renderSSRHead(head) sees
it, then in useEffect add or replace the client-only onRendered callback (or
update the entry) to attach the onRendered behavior for the browser; use the
existing symbols head.push, headRef.current, getHeadChanges and the useEffect
block to perform the client-side update/cleanup so SSR and client both get
correct registration.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@packages/react/src/helmet.ts`:
- Around line 29-52: HelmetProps currently lacks prop-based fields (title, meta,
link, script, style, noscript, base, htmlAttributes, bodyAttributes) so
prop-based react-helmet usage won't work; update the type and mapping in
getHeadChanges() to accept and translate these props into the UseHeadInput
shape. Specifically, extend the HelmetProps interface to include title?: string,
meta?: Array<Record<string, any>>, link?: Array<Record<string, any>>, script?:
Array<Record<string, any>>, style?: Array<Record<string, any>>, noscript?:
Array<Record<string, any>>, base?: Record<string, any>, htmlAttributes?:
Record<string, any>, bodyAttributes?: Record<string, any> (keep existing
defaultTitle/titleTemplate/onChangeClientState), then modify getHeadChanges(…)
to detect and merge values from those props into the produced UseHeadInput
(mapping title -> title, meta -> meta tags, link -> link tags, etc.), ensuring
children-based head entries are merged or overridden consistently and that
onChangeClientState/defaultTitle/titleTemplate behavior is preserved.

---

Duplicate comments:
In `@packages/react/src/helmet.ts`:
- Around line 181-197: The onRendered handler in useEffect currently builds a
partial react-helmet state and calls cb(state, {}, {}); update it to produce the
full react-helmet shape by including htmlAttributes (document.documentElement
attributes), bodyAttributes (document.body attributes), baseTag (the singular
<base> element or null), and noscriptTags
(Array.from(document.querySelectorAll('noscript'))), and replace the
always-empty addedTags/removedTags with actual arrays computed by diffing the
current head tags against a previous snapshot stored in a ref (e.g.,
prevHeadTagsRef) that you update after calling onChangeClientStateRef.current;
keep the existing title and tag collections but compute addedTags/removedTags
from those collections and pass cb(state, addedTags, removedTags).