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John Henry · Open Source

Bugs found while merging

Most of @johnhenry/domable’s six source modules had no tests at all before they were consolidated into this package. Testing them together for the first time surfaced real bugs — fixed here, not silently ported:

  • react-to-dom: referenced a bare react.type/react.props that was never in scope (the function’s own parameter was destructured directly) — every call to the non-fragment path threw a ReferenceError.
  • react-to-dom: a Fragment’s props.children was assumed to already be an array, but real React (and domToReact) can hand back a single, non-array child — crashed on .map().
  • dom-to-React: a DocumentFragment’s children were pushed into a children array declared after that code ran — guaranteed ReferenceError the moment a fragment was converted.
  • dom-to-React: attributes were read via Object.entries(dom.attributes) — dom.attributes is a NamedNodeMap, not a plain object, so this never actually produced [name, value] pairs; no attribute ever made it into props.
  • text-to-DOM-nodes: parsed via DOMParser(...).body.childNodes. Per the HTML parsing spec, <style>/<script>/<link>/<meta>/<title>/ <base> are parsed using “in head” rules even inside a <body> context — they silently end up in the parsed document’s <head> and never appear in .body.childNodes. simple-element’s own README used a <style>-in- shadowOpen example as its lead “Styling Elements” demo — meaning that exact documented pattern silently produced no styling at all, in every browser, the whole time. Fixed by parsing into an HTMLTemplateElement’s .content instead (the standard technique for parsing an HTML fragment without element-specific top-of-document reinterpretation) — also simpler, since .content is already a real DocumentFragment.
  • create-element: createElement(oneNode) (a single bare Node argument, nothing else) silently gained a second, bogus child from the props = {} default value being swept into the children array alongside the real one. Surfaced by reactToDom’s Fragment-with-one-child path.
  • simple-element’s own (previously unexported, untested) useShadow: false branch appended light-DOM children directly inside the constructor — which the Custom Elements spec forbids (only shadow-DOM content is allowed synchronously during construction; real browsers enforce this too). Fixed by deferring light-DOM content to connectedCallback() (guarded against duplicating on reconnect).

None of these were reachable from any single module’s own test suite (most had none) — each surfaced only once another converted module fed it the exact input shape it had never actually been exercised against.