Lets user reset their choice of Merge Target

(#4224, #4258)

Author: dv

src/commands/changeUserDefinedMergeBase.ts

@@ -4,7 +4,7 @@ import type { Repository } from '../git/models/repository';
 import type { ViewsWithRepositoryFolders } from '../views/viewBase';
 import type { PartialStepState, StepGenerator, StepState } from './quickCommand';
 import { endSteps, QuickCommand, StepResultBreak } from './quickCommand';
-import { pickBranchOrTagStep, pickBranchStep, pickRepositoryStep } from './quickCommand.steps';
+import { pickBranchStep, pickOrResetBranchStep, pickRepositoryStep } from './quickCommand.steps';
 
 interface Context {
 	repos: Repository[];
@@ -84,22 +84,30 @@ export class ChangeUserDefinedMergeBaseCommand extends QuickCommand {
 				state.branch = branches.name;
 			}
 
-			const result = yield* pickBranchOrTagStep(state, context, {
+			if (!state.mergeBranch) {
+				state.mergeBranch = await this.container.git
+					.branches(state.repo.path)
+					.getBaseBranchName?.(state.branch);
+			}
+
+			const detectedMergeTarget = await this.container.git
+				.branches(state.repo.path)
+				.getBaseBranchName?.(state.branch, true);
+
+			const result = yield* pickOrResetBranchStep(state, context, {
 				picked: state.mergeBranch,
 				placeholder: 'Pick a merge target branch',
-				value: undefined,
-				filter: {
-					branches: (branch: GitBranch) => branch.remote && branch.name !== state.branch,
-					tags: () => false,
-				},
+				filter: (branch: GitBranch) => branch.remote && branch.name !== state.branch,
+				resetTitle: 'Reset Merge Target',
+				resetDescription: `Reset to "${detectedMergeTarget}"`,
 			});
 			if (result === StepResultBreak) {
 				continue;
 			}
-			if (result && state.branch) {
+			if (state.branch) {
 				await this.container.git
 					.branches(state.repo.path)
-					.setUserDefinedBaseBranchName?.(state.branch, result.name);
+					.setUserDefinedBaseBranchName?.(state.branch, result?.name);
 			}
 
 			endSteps(state);

src/commands/quickCommand.steps.ts

@@ -783,6 +783,84 @@ export function* pickBranchStep<
 	return canPickStepContinue(step, state, selection) ? selection[0].item : StepResultBreak;
 }
 
+export function* pickOrResetBranchStep<
+	State extends PartialStepState & { repo: Repository },
+	Context extends { repos: Repository[]; showTags?: boolean; title: string },
+>(
+	state: State,
+	context: Context,
+	{
+		filter,
+		picked,
+		placeholder,
+		title,
+		resetTitle,
+		resetDescription,
+	}: {
+		filter?: (b: GitBranch) => boolean;
+		picked?: string | string[];
+		placeholder: string;
+		title?: string;
+		resetTitle: string;
+		resetDescription: string;
+	},
+): StepResultGenerator<GitBranchReference | undefined> {
+	const items = getBranches(state.repo, {
+		buttons: [RevealInSideBarQuickInputButton],
+		filter: filter,
+		picked: picked,
+	}).then(branches =>
+		branches.length === 0
+			? [createDirectiveQuickPickItem(Directive.Back, true), createDirectiveQuickPickItem(Directive.Cancel)]
+			: [
+					createDirectiveQuickPickItem(Directive.Reset, false, {
+						label: resetTitle,
+						description: resetDescription,
+					}),
+					...branches,
+			  ],
+	);
+
+	const resetButton: QuickInputButton = {
+		iconPath: new ThemeIcon('notebook-revert'),
+		tooltip: resetDescription,
+	};
+	let resetButtonClicked = false;
+	const step = createPickStep<BranchQuickPickItem>({
+		title: appendReposToTitle(title ?? context.title, state, context),
+		placeholder: count => (!count ? `No branches found in ${state.repo.formattedName}` : placeholder),
+		matchOnDetail: true,
+		items: items,
+		additionalButtons: [resetButton],
+		onDidClickButton: (_quickpick, button) => {
+			if (button === resetButton) {
+				resetButtonClicked = true;
+				return true;
+			}
+			return false;
+		},
+		onDidClickItemButton: (_quickpick, button, { item }) => {
+			if (button === RevealInSideBarQuickInputButton) {
+				void BranchActions.reveal(item, { select: true, focus: false, expand: true });
+			}
+		},
+		keys: ['right', 'alt+right', 'ctrl+right'],
+		onDidPressKey: async (_quickpick, _key, { item }) => {
+			await BranchActions.reveal(item, {
+				select: true,
+				focus: false,
+				expand: true,
+			});
+		},
+	});
+
+	const selection: StepSelection<typeof step> = yield step;
+	if (resetButtonClicked) {
+		return undefined;
+	}
+	return canPickStepContinue(step, state, selection) ? selection[0].item : StepResultBreak;
+}
+
 export function* pickBranchesStep<
 	State extends PartialStepState & { repo: Repository },
 	Context extends { repos: Repository[]; showTags?: boolean; title: string },

src/env/node/git/sub-providers/branches.ts

@@ -574,7 +574,7 @@ export class BranchesGitSubProvider implements GitBranchesSubProvider {
 	}
 
 	@log({ exit: true })
-	async getBaseBranchName(repoPath: string, ref: string): Promise<string | undefined> {
+	async getBaseBranchName(repoPath: string, ref: string, detectedOnly?: boolean): Promise<string | undefined> {
 		try {
 			const pattern = `^branch\\.${ref}\\.`;
 			const data = await this.git.config__get_regex(pattern, repoPath);
@@ -592,7 +592,7 @@ export class BranchesGitSubProvider implements GitBranchesSubProvider {
 					if (match == null) break;
 
 					const [, key, value] = match;
-					if (key === 'gk-user-defined-merge-base' && gkUserPriority <= priority) {
+					if (!detectedOnly && key === 'gk-user-defined-merge-base' && gkUserPriority <= priority) {
 						mergeBase = value;
 						update = false;
 					} else if (key === 'gk-merge-base' && gkDetectedPriority <= priority) {
@@ -633,7 +633,7 @@ export class BranchesGitSubProvider implements GitBranchesSubProvider {
 	}
 
 	@log()
-	async setUserDefinedBaseBranchName(repoPath: string, ref: string, base: string): Promise<void> {
+	async setUserDefinedBaseBranchName(repoPath: string, ref: string, base: string | undefined): Promise<void> {
 		const mergeBaseConfigKey: GitConfigKeys = `branch.${ref}.gk-user-defined-merge-base`;
 		await this.provider.config.setConfig(repoPath, mergeBaseConfigKey, base);
 	}

src/git/gitProvider.ts

@@ -254,9 +254,9 @@ export interface GitBranchesSubProvider {
 		branch: string,
 		targetBranch: string,
 	): Promise<MergeConflict | undefined>;
-	getBaseBranchName?(repoPath: string, ref: string): Promise<string | undefined>;
+	getBaseBranchName?(repoPath: string, ref: string, detectedOnly?: boolean): Promise<string | undefined>;
 	setBaseBranchName?(repoPath: string, ref: string, base: string): Promise<void>;
-	setUserDefinedBaseBranchName?(repoPath: string, ref: string, base: string): Promise<void>;
+	setUserDefinedBaseBranchName?(repoPath: string, ref: string, base: string | undefined): Promise<void>;
 	getTargetBranchName?(repoPath: string, ref: string): Promise<string | undefined>;
 	setTargetBranchName?(repoPath: string, ref: string, target: string): Promise<void>;
 	renameBranch?(repoPath: string, oldName: string, newName: string): Promise<void>;

src/quickpicks/items/directive.ts

@@ -5,6 +5,7 @@ import { pluralize } from '../../system/string';
 export enum Directive {
 	Back,
 	Cancel,
+	Reset,
 	LoadMore,
 	Noop,
 	Reload,
@@ -57,6 +58,9 @@ export function createDirectiveQuickPickItem(
 			case Directive.Reload:
 				label = 'Refresh';
 				break;
+			case Directive.Reset:
+				label = 'Reset';
+				break;
 			case Directive.SignIn:
 				label = 'Sign In';
 				break;