---
id: "bbcb2adc-4150-44f2-8128-3546a92bafaa"
name: "Lightning form fill via shadow DOM"
micro_summary: "SF Lightning form fields live in NESTED shadow roots; deep-walk to lightning-combobox, whose trigger sits one level deeper inside lightning-base-combobox. Reliable recipe: open -> wait ~0.7s -> pick (options render lazily). Helpers in the config-workspace sf_combo.js. Direct URL ?recordTypeId=<id> skips the record-type picker modal."
status: "resolved"
see_also: []
scope: "Fill and submit Salesforce Lightning record edit forms whose fields live in nested shadow DOM (comboboxes, required picklists), and create records via UI from browser-harness."
warnings: "Inline JS inside the old `browser-harness -c \"...\"` runner breaks on escaped quotes; the current stdin runner (see Runtime Invocation) avoids that — load JS from a file and read() it when needed. Combobox options render ~600ms AFTER opening: always open -> wait ~0.7s -> pick, never open+read+click in one call."
---
## The shadow-DOM trap

Top-level `document.querySelectorAll("lightning-combobox")` returns 0 — the record edit form is inside nested shadow roots. You must recurse shadow roots. And the clickable trigger is not on `lightning-combobox` directly; it is one level deeper inside its child `lightning-base-combobox` shadowRoot.

## Helpers: config-workspace sf_combo.js

Inject once per navigation (`window.*` funcs are wiped on nav):
- `__bh_combo(label)` — deep-walk shadow roots, find combobox by label (strips leading `*`).
- `__bh_openCombo(label)` / `__bh_pickOption(label,value)` — open, then (after a wait) pick. Options render ~600ms AFTER opening, so never open+read+click in one call.
- `__bh_clickBtn(text)` — deep click a button by visible text (e.g. "Save").
- `__bh_requiredFields()` — enumerate required-field labels+tags to know what a record type needs.

## Create a record (Case example)

Direct URL SKIPS the record-type picker (more reliable than clicking shadow radios):
`/lightning/o/Case/new?nooverride=1&recordTypeId=<id>`
Then: inject sf_combo.js -> openCombo -> wait 0.7 -> pickOption -> clickBtn("Save") -> poll url for `/lightning/r/`.

## Quoting trap

The old `browser-harness -c "..."` runner broke on escaped quotes; the current stdin runner (see Runtime Invocation) is the safe path. Put JS in a FILE and `open(path).read()` it, then `cdp("Runtime.evaluate", expression=js)`.