---
name: ms-teams-multiline-typing
description: Use when typing a multiline message into the MS Teams chat compose box via Chrome DevTools MCP. Covers the Shift+Enter newline pattern and why literal \n fails. Use ONLY when the user asks to type or compose a multi-paragraph message in MS Teams.
---

# MS Teams multiline typing

How to insert line breaks when composing a message in Microsoft Teams via
Chrome DevTools MCP. Verified empirically against the live Teams web app.

## The input element

- `<div role="textbox" contenteditable="true">` — a CKEditor instance
  wrapped in FluentUI. State lives in CKEditor's model, not the DOM.
- Exposed in the a11y snapshot as `textbox "Type a message" multiline`.

## Plain text (single line)

```
chrome-devtools_type_text  text: "Hello"
```

Works as expected — text is inserted into the current `<p>`.

## Multiline text — REQUIRED pattern

CKEditor **rejects** raw `\n` characters. A single `type_text` call with an
embedded newline silently drops the **entire** input (not just the
newline); the editor stays empty. Confirmed empirically:

| Input method | Result |
| --- | --- |
| `type_text "A\nB\nC"` | editor empty, nothing inserted |
| `type_text "A"` then `Shift+Enter` then `type_text "B"` | two `<p>` blocks inserted |

Therefore multiline messages MUST be built by alternating `type_text` and
`Shift+Enter`:

```
chrome-devtools_type_text  text: "Line 1"
chrome-devtools_press_key  key: "Shift+Enter"
chrome-devtools_type_text  text: "Line 2"
chrome-devtools_press_key  key: "Shift+Enter"
chrome-devtools_type_text  text: "Line 3"
```

Each `Shift+Enter` dispatches a real `KeyboardEvent('keydown', {key:
'Enter', shiftKey: true})`, which CKEditor's keydown handler intercepts
to execute `enterShift` and insert a new `<p>` into the model.

## Why `\n` fails (mechanism)

CKEditor routes text insertion through its model via `beforeinput`/`input`
events. A raw `\n` does not map to any `inputType` (`insertParagraph` and
`insertLineBreak` are the valid ones, both triggered by keystrokes, not by
literal newline chars). When the handler can't route the input, the entire
insert is rejected — not partially applied.

## Verifying the draft

```js
() => {
  const e = document.querySelector('[role="textbox"]');
  return { innerText: e.innerText, pCount: e.querySelectorAll('p').length };
}
```

## Do NOT

- Do not use `chrome-devtools_fill` with `\n` on the Teams editor — it
  fails silently for the same reason as `type_text` with `\n`.
- Do not mutate `innerHTML` directly — Teams enforces TrustedHTML policy
  and the assignment throws.

## Generalizing to other chat apps

Same `type_text` + `Shift+Enter` pattern works for Slack, WhatsApp Web,
and Gosuslugi chat. Always probe the element type first: a true `<textarea>`
accepts `\n` in `fill` directly; a `contenteditable` requires the keystroke approach.