Uses a new AI prompt for generating Pull Request details

(vscode-gitlens-private#43, #4177)

Author: sergeibbb

src/commands/createPullRequestOnRemote.ts

@@ -84,10 +84,15 @@ export class CreatePullRequestOnRemoteCommand extends GlCommandBase {
 				}
 				const baseRef = `${base.remote.name}/${base.branch}`;
 				const compareRef = `${compare.remote.name}/${compare.branch}`;
-				const result = await this.container.ai.generatePullRequestMessage(repo, baseRef, compareRef, {
-					source: 'home', // TODO provide the real source
-				});
-				return result?.parsed;
+				try {
+					const result = await this.container.ai.generatePullRequestMessage(repo, baseRef, compareRef, {
+						source: 'scm-input',
+					});
+					return result?.parsed;
+				} catch (e) {
+					void window.showErrorMessage(`Unable to generate pull request message: ${e}`);
+					return undefined;
+				}
 			},
 		};
 

src/plus/ai/aiProviderService.ts

@@ -543,14 +543,14 @@ export class AIProviderService implements Disposable {
 		}
 
 		const result = await this.sendRequest(
-			'generate-commitMessage',
+			'generate-pullRequestMessage',
 			() => ({
 				diff: diff?.contents ?? '',
 				data: commits.sort((a, b) => a[1] - b[1]).map(c => c[0]),
 				context: options?.context ?? '',
 				instructions: configuration.get('ai.generateCommitMessage.customInstructions') ?? '',
 			}),
-			m => `Generating commit message with ${m.name}...`,
+			m => `Generating pull request details with ${m.name}...`,
 			source,
 			m => ({
 				key: 'ai/generate',

src/plus/ai/models/model.ts

@@ -26,6 +26,7 @@ export interface AIModelDescriptor<Provider extends AIProviders = AIProviders, M
 
 export type AIActionType =
 	| 'generate-commitMessage'
+	| 'generate-pullRequestMessage'
 	| 'generate-stashMessage'
 	| 'generate-changelog'
 	| `generate-create-${'cloudPatch' | 'codeSuggestion' | 'pullRequest'}`

src/plus/ai/models/promptTemplates.ts

@@ -9,6 +9,7 @@ export interface PromptTemplate {
 
 export type PromptTemplateContext<T extends AIActionType> = T extends
 	| 'generate-commitMessage'
+	| 'generate-pullRequestMessage'
 	| 'generate-stashMessage'
 	| 'generate-create-cloudPatch'
 	| 'generate-create-codeSuggestion'

src/plus/ai/prompts.ts

@@ -49,6 +49,61 @@ Fixes #789
 
 Based on the provided code diff and any additional context, create a concise but meaningful commit message following the instructions above.`;
 
+export const generatePullRequestMessageUserPrompt = `You are an advanced AI programming assistant and are tasked with summarizing code changes into a concise but meaningful pull request title and description. You will be provided with a code diff and a list of commits. Your goal is to analyze the changes and create a clear, informative title and description that accurately represents the modifications made to the code.
+First, examine the following code changes provided in Git diff format:
+<~~diff~~>
+\${diff}
+</~~diff~~>
+
+Then, review the list of commits to help understand the motivation behind the changes and any relevant background information:
+<~~data~~>
+\${data}
+</~~data~~>
+
+Now, if provided, use this context to understand the motivation behind the changes and any relevant background information:
+<~~additional-context~~>
+\${context}
+</~~additional-context~~>
+
+To create an effective pull request title and description, follow these steps:
+
+1. Carefully analyze the diff, commit messages, context, focusing on:
+   - The purpose and rationale of the changes
+   - Any problems addressed or benefits introduced
+   - Any significant logic changes or algorithmic improvements
+2. Ensure the following when composing the pull request title and description:
+   - Emphasize the 'why' of the change, its benefits, or the problem it addresses
+   - Use an informal yet professional tone
+   - Use a future-oriented manner, third-person singular present tense (e.g., 'Fixes', 'Updates', 'Improves', 'Adds', 'Removes')
+   - Be clear and concise
+   - Synthesize only meaningful information from the diff and context
+   - Avoid outputting code, specific code identifiers, names, or file names unless crucial for understanding
+   - Avoid repeating information, broad generalities, and unnecessary phrases like "this", "this commit", or "this change"
+3. Summarize the main purpose of the changes in a single, concise sentence, which will be the title of your pull request message
+   - Start with a third-person singular present tense verb
+   - Limit to 50 characters if possible
+4. If necessary, provide a brief explanation of the changes, which will be the body of your pull request message
+   - Add line breaks for readability and to separate independent ideas
+   - Focus on the "why" rather than the "what" of the changes.
+   - Structure the body with markdown bullets and headings for clarity
+5. If the changes are related to a specific issue or ticket, include the reference (e.g., "Fixes #123" or "Relates to JIRA-456") at the end of the pull request message.
+
+Write your title inside <summary> tags and your description inside <body> tags and include no other text:
+
+<summary>
+Implements user authentication feature
+</summary>
+<body>
+Adds login and registration endpoints:
+- Updates user model to include password hashing
+- Integrates JWT for secure token generation
+
+Fixes #789
+</body>
+\${instructions}
+
+Based on the provided code diff, commit list, and any additional context, create a concise but meaningful pull request title and body following the instructions above.`;
+
 export const generateStashMessageUserPrompt = `You are an advanced AI programming assistant and are tasked with creating a concise but descriptive stash message. You will be provided with a code diff of uncommitted changes. Your goal is to analyze the changes and create a clear, single-line stash message that accurately represents the work in progress being stashed.
 
 First, examine the following code changes provided in Git diff format:

src/plus/ai/utils/-webview/ai.utils.ts

@@ -25,6 +25,8 @@ export function getActionName(action: AIActionType): string {
 	switch (action) {
 		case 'generate-commitMessage':
 			return 'Generate Commit Message';
+		case 'generate-pullRequestMessage':
+			return 'Generate Pull Request Details';
 		case 'generate-stashMessage':
 			return 'Generate Stash Message';
 		case 'generate-changelog':

src/plus/ai/utils/-webview/prompt.utils.ts

@@ -8,6 +8,7 @@ import {
 	generateCloudPatchMessageUserPrompt,
 	generateCodeSuggestMessageUserPrompt,
 	generateCommitMessageUserPrompt,
+	generatePullRequestMessageUserPrompt,
 	generateStashMessageUserPrompt,
 } from '../../prompts';
 
@@ -19,6 +20,12 @@ export function getLocalPromptTemplate<T extends AIActionType>(action: T, _model
 				template: generateCommitMessageUserPrompt,
 				variables: ['diff', 'context', 'instructions'],
 			};
+		case 'generate-pullRequestMessage':
+			return {
+				name: 'Generate Pull Request Details',
+				template: generatePullRequestMessageUserPrompt,
+				variables: ['diff', 'data', 'context', 'instructions'],
+			};
 		case 'generate-stashMessage':
 			return {
 				name: 'Generate Stash Message',