chat: enable native autocorrect on web mobile chat inputs

[osortega]

Summary

Mobile soft keyboards rely on the input element's autocorrect, autocapitalize and spellcheck attributes to decide whether to run auto-correction and auto-capitalization while typing. Monaco hardcoded all three to off on both the <textarea> and native EditContext input elements, which meant the chat inputs in vscode.dev/agents on a phone got no auto-correction at all — typing prose on a phone there was unforgiving.

Chat inputs are prose, not code, so we want the mobile keyboard's full assistance there.

Changes

1. New internal editor option inputAids (src/vs/editor/common/config/editorOptions.ts)

   • Default false, no settings schema — internal-only for now.
   • When true, flips autocorrect=on, autocapitalize=on, spellcheck=true on the editor's input element. The autocomplete attribute (form autofill) is intentionally left at off.

2. Wired through both edit-context implementations

   • src/vs/editor/browser/controller/editContext/textArea/textAreaEditContext.ts
   • src/vs/editor/browser/controller/editContext/native/nativeEditContext.ts
   • Attributes are written from a single helper that runs on construction and on onConfigurationChanged, so the value stays correct across the editor.editContext flip and any other config changes.

3. Enabled for web mobile only in the two chat input call sites:

   • src/vs/workbench/contrib/chat/browser/widget/input/chatInputPart.ts (workbench ChatInputPart)
   • src/vs/sessions/contrib/chat/browser/newChatInput.ts (agents-window NewChatInputWidget)
   • Gate: inputAids: isWeb && isMobile. Other Monaco editors (find widget, rename input, etc.) are unaffected.

Resulting matrix

Surface	Desktop (Electron)	Web desktop	Web mobile
Workbench chat (ChatInputPart)	off	off	on
/agents new-chat (NewChatInputWidget)	off	off	on

Testing

• npm run compile-check-ts-native — clean
• npm run valid-layers-check — clean
• Manual: still need to verify on iOS Safari and Android Chrome that typing into a chat input shows the keyboard's auto-correct suggestions and auto-capitalizes the start of sentences. Both editor.editContext: true and false paths should be exercised.

Why the editor-option approach

We considered a DOM-mutation alternative (querying .inputarea/.native-edit-context after editor creation and flipping the attributes from the chat input itself). The editor-option route was chosen because:

• it survives the editor.editContext setting flip, which recreates the input element;
• it doesn't couple chat code to internal Monaco class names; and
• the existing attribute setting in the two edit contexts was already split across two files — centralizing it via the option is a small cleanup.

The option is intentionally undocumented in user settings; if a future use case warrants it, we can add a schema description.

[Copilot]

Pull request overview

Enables native mobile keyboard assistance (autocorrect/autocapitalize/spellcheck) for chat inputs on web mobile by introducing an internal editor option that controls these attributes on Monaco’s input element across both textarea and native EditContext implementations.

Changes:

• Added a new internal editor option inputAids (default false) to toggle native input aid attributes on the editor input element.
• Applied inputAids in both textarea- and native-EditContext input implementations, including updating on configuration changes.
• Enabled inputAids only for web mobile chat inputs in the workbench chat input and the Agents window new-chat input.

Show a summary per file

File	Description
src/vs/workbench/contrib/chat/browser/widget/input/chatInputPart.ts	Enables inputAids for workbench chat input on web mobile only.
src/vs/sessions/contrib/chat/browser/newChatInput.ts	Enables inputAids for Agents window chat input on web mobile only.
src/vs/editor/common/config/editorOptions.ts	Introduces internal editor option inputAids and registers it (no settings schema).
src/vs/editor/browser/controller/editContext/textArea/textAreaEditContext.ts	Centralizes writing autocorrect/autocapitalize/spellcheck on the textarea based on inputAids (constructor + config changes).
src/vs/editor/browser/controller/editContext/native/nativeEditContext.ts	Writes autocorrect/autocapitalize/spellcheck on the native EditContext host element based on inputAids (constructor + config changes).

Copilot's findings

• Files reviewed: 5/5 changed files
• Comments generated: 0