Erase as |…| block-param clause when Glint substitutes a block-form component

[johanrd]

Summary

When Glint resolves a yielding component to a native tag (e.g. <MyList as |item|> → <div>), the in-place open-tag rename in handleGlintSubstitution's block-form path renamed <MyList> → <div> but left the as |item| clause in place. html-validate's parser then treated |item| as an attribute, firing attr-case (Attribute "|item|" should be lowercase); downstream rules like element-permitted-content cascaded.

The rendered DOM has no such attribute — block params are a Glimmer-side binding for yielded content, not HTML — so the blanker must erase the as |…| clause when it does the in-place rename.

Implementation

In the block-form Glint substitution path, when node.blockParams.length > 0, scan the open-tag text for \bas\s+\|[^|]*\| and add the LAST match to blankRanges. The last match is unambiguously the block-params clause (per Glimmer syntax it's always the rightmost thing before >), defending against the rare case where an attribute value happens to contain a literal as |x|.

Surfaced by

Ecosystem CI on hashicorp/design-system: 881× spurious attr-case plus a cascade of element-permitted-content and element-required-attributes reports — all rooted in this single leak. After the fix HDS dropped from 1184 → 303 findings (with Glint enabled).

Test plan

• New test: block-form <MyList as |item|> substituted to <div> — |item| must not appear in output
• New test: multi-param as |item index| covered by the same regex
• npm test — 129/129 passing
• npm run typecheck:tests — clean
• npm run build — clean

[Copilot]

Pull request overview

Fixes a false-positive cascade in html-validate output when Glint substitutes a yielding, block-form component invocation (e.g. <MyList as |item|>…</MyList>) to a native tag by ensuring the Glimmer-only block-param clause is removed from the emitted open tag.

Changes:

• In block-form Glint substitution, detect and blank the last as |…| clause in the open-tag source span when node.blockParams are present.
• Add unit tests asserting that |…| block-param syntax does not leak into the blanked output for substituted block-form components.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
blank.ts	Blanks the `as
test/blank.test.ts	Adds regression tests to ensure block-param syntax is removed when substituting block-form components to native tags.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.