Function handler

chat-sample/src/simple.ts:17–89

(request: vscode.ChatRequest, context: vscode.ChatContext, stream: vscode.ChatResponseStream, token: vscode.CancellationToken)

	// Define a Cat chat handler.
	const handler: vscode.ChatRequestHandler = async (request: vscode.ChatRequest, context: vscode.ChatContext, stream: vscode.ChatResponseStream, token: vscode.CancellationToken): Promise<ICatChatResult> => {
		// To talk to an LLM in your subcommand handler implementation, your
		// extension can use VS Code's `requestChatAccess` API to access the Copilot API.
		// The GitHub Copilot Chat extension implements this provider.
		if (request.command === 'randomTeach') {
			stream.progress('Picking the right topic to teach...');
			const topic = getTopic(context.history);
			try {
				const messages = [
					vscode.LanguageModelChatMessage.User('You are a cat! Your job is to explain computer science concepts in the funny manner of a cat. Always start your response by stating what concept you are explaining. Always include code samples.'),
					vscode.LanguageModelChatMessage.User(topic)
				];

				const chatResponse = await request.model.sendRequest(messages, {}, token);
				for await (const fragment of chatResponse.text) {
					stream.markdown(fragment);
				}

			} catch (err) {
				handleError(logger, err, stream);
			}

			stream.button({
				command: CAT_NAMES_COMMAND_ID,
				title: vscode.l10n.t('Use Cat Names in Editor')
			});

			logger.logUsage('request', { kind: 'randomTeach' });
			return { metadata: { command: 'randomTeach' } };
		} else if (request.command === 'play') {
			stream.progress('Throwing away the computer science books and preparing to play with some Python code...');
			try {
				// Here's an example of how to use the prompt-tsx library to build a prompt
				const { messages } = await renderPrompt(
					PlayPrompt,
					{ userQuery: request.prompt },
					{ modelMaxPromptTokens: request.model.maxInputTokens },
					request.model);

				const chatResponse = await request.model.sendRequest(messages, {}, token);
				for await (const fragment of chatResponse.text) {
					stream.markdown(fragment);
				}

			} catch (err) {
				handleError(logger, err, stream);
			}

			logger.logUsage('request', { kind: 'play' });
			return { metadata: { command: 'play' } };
		} else {
			try {
				const messages = [
					vscode.LanguageModelChatMessage.User(`You are a cat! Think carefully and step by step like a cat would.
                        Your job is to explain computer science concepts in the funny manner of a cat, using cat metaphors. Always start your response by stating what concept you are explaining. Always include code samples.`),
					vscode.LanguageModelChatMessage.User(request.prompt)
				];