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fix(core/title): detect id="title" collision and use fallback #5285

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fix(core/title): detect id="title" collision and use fallback #5285

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fix(core/title): detect id="title" collision and use fallback
marcoscaceres May 9, 2026
4a3dd61
Merge branch 'main' into fix/4712-title-id-collision
marcoscaceres Aug 11, 2026
d657a8c
test(core/title): add tests for id="title" collision fallback
Copilot Aug 11, 2026
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13 changes: 12 additions & 1 deletion src/core/title.js
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Original file line number Diff line number Diff line change
Expand Up @@ -51,7 +51,18 @@ export function run(conf) {
}

// Decorate the spec title
if (!h1Elem.id) h1Elem.id = "title";
if (!h1Elem.id) {

@marcoscaceres marcoscaceres Aug 11, 2026

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This needs a test. @copilot, can you add a test for this?

Copilot AI Aug 11, 2026

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Added tests/spec/core/title-spec.js with two tests:

  1. Verifies that when another element already has id="title", the <h1> falls back to id="document-title" and a core/title error is emitted.
  2. Verifies normal behavior (no collision) — <h1> keeps id="title" and no error is emitted.

const existing = document.getElementById("title");
if (existing && existing !== h1Elem) {
const msg =
'Another element already uses `id="title"`. ' +
"The spec's `<h1>` will use a different id to avoid a collision.";
showError(msg, name, { elements: [existing] });
h1Elem.id = "document-title";
} else {
h1Elem.id = "title";
}
}
h1Elem.classList.add("title");

setDocumentTitle(conf, h1Elem);
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