Fix partial markdown when it's lazy

[roblourens]

Fix an issue where only the first token of thinking text would be rendered in a collapsed thinking block

[justschen]

we all agree this is a great PR thanks @roblourens 😆

[Copilot]

Pull request overview

Fixes collapsed/lazy “thinking” rendering so that streaming updates are reflected correctly when the user expands the thinking block.

Changes:

• Update ChatThinkingContentPart to keep pending lazy thinking items up-to-date during streaming and avoid duplicate/stale containers on expand.
• Add tests covering lazy thinking + streaming updates and a non-streaming edge case.
• Remove an unused ESLint disable directive from the test file.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/vs/workbench/contrib/chat/test/browser/widget/chatContentParts/chatThinkingContentPart.test.ts	Adds regression tests for lazy thinking behavior (streaming and non-streaming) and removes an unused ESLint disable.
src/vs/workbench/contrib/chat/browser/widget/chatContentParts/chatThinkingContentPart.ts	Updates lazy-thinking materialization and streaming update propagation to prevent stale/duplicate thinking content after expansion.

[Copilot]

initContent skips creating/rendering the initial textContainer whenever any lazy thinking item exists. This can drop the constructor’s initial thinking text when another thinking section is queued via setupThinkingContainer before the part is expanded (initial content non-empty + later lazy thinking item). Consider preserving the initial thinking content (e.g. store it as a lazy thinking item when collapsed, or only skip when that initial content is already represented by a pending lazy item).

Suggested change

	// Only create textContainer here if there's no pending lazy thinking item.
	// If there's a lazy thinking item, it will be rendered via materializeLazyItem
	// with the latest streaming content.
	const hasLazyThinkingItems = this.lazyItems.some(item => item.kind === 'thinking');
	if (this.currentThinkingValue && !hasLazyThinkingItems) {
	// Render any initial thinking content captured before expansion.
	if (this.currentThinkingValue) {

[roblourens]

And you were all wrong