Adds branch merge target merge detection

Adds fetch and comparison actions to merge target
Adds merged indicator status to active section on Home

Author: eamodio

Diff for: src/constants.commands.ts

@@ -685,6 +685,7 @@ export type TreeViewCommandSuffixesByViewType<T extends TreeViewTypes> = Extract
 >;
 
 type HomeWebviewCommands = `home.${
+	| 'openMergeTargetComparison'
 	| 'openPullRequestChanges'
 	| 'openPullRequestComparison'
 	| 'openPullRequestOnRemote'

Diff for: src/env/node/git/sub-providers/branches.ts

@@ -5,12 +5,14 @@ import { GitErrorHandling } from '../../../../git/commandOptions';
 import type {
 	BranchContributionsOverview,
 	GitBranchesSubProvider,
+	GitBranchMergedStatus,
 	PagedResult,
 	PagingOptions,
 } from '../../../../git/gitProvider';
 import { GitBranch } from '../../../../git/models/branch';
 import { getLocalBranchByUpstream, isDetachedHead } from '../../../../git/models/branch.utils';
 import type { MergeConflict } from '../../../../git/models/mergeConflict';
+import type { GitBranchReference } from '../../../../git/models/reference';
 import { createRevisionRange } from '../../../../git/models/revision.utils';
 import { parseGitBranches } from '../../../../git/parsers/branchParser';
 import { parseMergeTreeConflict } from '../../../../git/parsers/mergeTreeParser';
@@ -310,6 +312,74 @@ export class BranchesGitSubProvider implements GitBranchesSubProvider {
 		await this.git.branch(repoPath, name, ref);
 	}
 
+	@log()
+	async getBranchMergedStatus(
+		repoPath: string,
+		branch: GitBranchReference,
+		into: GitBranchReference,
+	): Promise<GitBranchMergedStatus> {
+		const result = await this.getBranchMergedStatusCore(repoPath, branch, into);
+		if (result.merged) return result;
+
+		// If the branch we are checking is a remote branch, check if it has been merged into its local branch (if there is one)
+		if (into.remote) {
+			const localIntoBranch = await this.getLocalBranchByUpstream(repoPath, into.name);
+			// If there is a local branch and it is not the branch we are checking, check if it has been merged into it
+			if (localIntoBranch != null && localIntoBranch.name !== branch.name) {
+				const result = await this.getBranchMergedStatusCore(repoPath, branch, localIntoBranch);
+				if (result.merged) {
+					return {
+						...result,
+						localBranchOnly: { name: localIntoBranch.name },
+					};
+				}
+			}
+		}
+
+		return { merged: false };
+	}
+
+	private async getBranchMergedStatusCore(
+		repoPath: string,
+		branch: GitBranchReference,
+		into: GitBranchReference,
+	): Promise<Exclude<GitBranchMergedStatus, 'localBranchOnly'>> {
+		const scope = getLogScope();
+
+		try {
+			// Check if branch is direct ancestor (handles FF merges)
+			try {
+				await this.git.exec(
+					{ cwd: repoPath, errors: GitErrorHandling.Throw },
+					'merge-base',
+					'--is-ancestor',
+					branch.name,
+					into.name,
+				);
+				return { merged: true, confidence: 'highest' };
+			} catch {}
+
+			// Cherry-pick detection (handles cherry-picks, rebases, etc)
+			const data = await this.git.exec<string>(
+				{ cwd: repoPath },
+				'cherry',
+				'--abbrev',
+				'-v',
+				into.name,
+				branch.name,
+			);
+			// Check if there are no lines or all lines startwith a `-` (i.e. likely merged)
+			if (!data || data.split('\n').every(l => l.startsWith('-'))) {
+				return { merged: true, confidence: 'high' };
+			}
+
+			return { merged: false };
+		} catch (ex) {
+			Logger.error(ex, scope);
+			return { merged: false };
+		}
+	}
+
 	@log()
 	async getLocalBranchByUpstream(repoPath: string, remoteBranchName: string): Promise<GitBranch | undefined> {
 		const branches = new PageableResult<GitBranch>(p =>
@@ -425,7 +495,12 @@ export class BranchesGitSubProvider implements GitBranchesSubProvider {
 			if (match != null && match.length === 2) {
 				let name: string | undefined = match[1];
 				if (name !== 'HEAD') {
-					name = await this.getValidatedBranchName(repoPath, options?.upstream ? `${name}@{u}` : name);
+					if (options?.upstream) {
+						const upstream = await this.getValidatedBranchName(repoPath, `${name}@{u}`);
+						if (upstream) return upstream;
+					}
+
+					name = await this.getValidatedBranchName(repoPath, name);
 					if (name) return name;
 				}
 			}
@@ -438,13 +513,17 @@ export class BranchesGitSubProvider implements GitBranchesSubProvider {
 				`--grep-reflog=checkout: moving from .* to ${ref.replace('refs/heads/', '')}`,
 			);
 			entries = data.split('\n').filter(entry => Boolean(entry));
-
 			if (!entries.length) return undefined;
 
 			match = entries[entries.length - 1].match(/checkout: moving from ([^\s]+)\s/);
 			if (match != null && match.length === 2) {
 				let name: string | undefined = match[1];
-				name = await this.getValidatedBranchName(repoPath, options?.upstream ? `${name}@{u}` : name);
+				if (options?.upstream) {
+					const upstream = await this.getValidatedBranchName(repoPath, `${name}@{u}`);
+					if (upstream) return upstream;
+				}
+
+				name = await this.getValidatedBranchName(repoPath, name);
 				if (name) return name;
 			}
 		} catch {}

Diff for: src/git/gitProvider.ts

@@ -370,6 +370,12 @@ export interface GitRepositoryProvider {
 	worktrees?: GitWorktreesSubProvider;
 }
 
+export type MergeDetectionConfidence = 'highest' | 'high' | 'medium';
+
+export type GitBranchMergedStatus =
+	| { merged: false }
+	| { merged: true; confidence: MergeDetectionConfidence; localBranchOnly?: { name: string } };
+
 export interface GitBranchesSubProvider {
 	getBranch(repoPath: string, name?: string): Promise<GitBranch | undefined>;
 	getBranches(
@@ -398,6 +404,18 @@ export interface GitBranchesSubProvider {
 	): Promise<string | undefined>;
 
 	createBranch?(repoPath: string, name: string, ref: string): Promise<void>;
+	/**
+	 * Returns whether a branch has been merged into another branch
+	 * @param repoPath The repository path
+	 * @param branch The branch to check if merged
+	 * @param into The branch to check if merged into
+	 * @returns A promise of whether the branch is merged
+	 */
+	getBranchMergedStatus?(
+		repoPath: string,
+		branch: GitBranchReference,
+		into: GitBranchReference,
+	): Promise<GitBranchMergedStatus>;
 	getLocalBranchByUpstream?(repoPath: string, remoteBranchName: string): Promise<GitBranch | undefined>;
 	getPotentialMergeOrRebaseConflict?(
 		repoPath: string,

Diff for: src/webviews/apps/plus/home/components/active-work.ts

@@ -9,8 +9,6 @@ import { createCommandLink } from '../../../../../system/commands';
 import { createWebviewCommandLink } from '../../../../../system/webview';
 import type { GetOverviewBranch, OpenInGraphParams, State } from '../../../../home/protocol';
 import { stateContext } from '../../../home/context';
-import { ipcContext } from '../../../shared/context';
-import type { HostIpc } from '../../../shared/ipc';
 import { linkStyles } from '../../shared/components/vscode.css';
 import { branchCardStyles, GlBranchCardBase } from './branch-card';
 import type { Overview, OverviewState } from './overviewState';
@@ -64,9 +62,6 @@ export class GlActiveWork extends SignalWatcher(LitElement) {
 	@consume({ context: overviewStateContext })
 	private _overviewState!: OverviewState;
 
-	@consume({ context: ipcContext })
-	private _ipc!: HostIpc;
-
 	override connectedCallback() {
 		super.connectedCallback();
 

Diff for: src/webviews/apps/plus/home/components/branch-card.ts

@@ -15,7 +15,7 @@ import type { AssociateIssueWithBranchCommandArgs } from '../../../../../plus/st
 import { createCommandLink } from '../../../../../system/commands';
 import { fromNow } from '../../../../../system/date';
 import { interpolate, pluralize } from '../../../../../system/string';
-import type { GetOverviewBranch, OpenInGraphParams } from '../../../../home/protocol';
+import type { BranchRef, GetOverviewBranch, OpenInGraphParams } from '../../../../home/protocol';
 import { renderBranchName } from '../../../shared/components/branch-name';
 import type { GlCard } from '../../../shared/components/card/card';
 import { GlElement, observe } from '../../../shared/components/element';
@@ -246,6 +246,7 @@ export abstract class GlBranchCardBase extends GlElement {
 		this.contributorsPromise = value?.contributors;
 		this.issuesPromise = value?.issues;
 		this.prPromise = value?.pr;
+		this.mergeTargetPromise = value?.mergeTarget;
 		this.wipPromise = value?.wip;
 	}
 
@@ -355,6 +356,26 @@ export abstract class GlBranchCardBase extends GlElement {
 		);
 	}
 
+	@state()
+	private _mergeTarget!: Awaited<GetOverviewBranch['mergeTarget']>;
+	get mergeTarget() {
+		return this._mergeTarget;
+	}
+
+	private _mergeTargetPromise!: GetOverviewBranch['mergeTarget'];
+	get mergeTargetPromise() {
+		return this._mergeTargetPromise;
+	}
+	set mergeTargetPromise(value: GetOverviewBranch['mergeTarget']) {
+		if (this._mergeTargetPromise === value) return;
+
+		this._mergeTargetPromise = value;
+		void this._mergeTargetPromise?.then(
+			r => (this._mergeTarget = r),
+			() => (this._mergeTarget = undefined),
+		);
+	}
+
 	@state()
 	private _wip!: Awaited<GetOverviewBranch['wip']>;
 	get wip() {
@@ -391,10 +412,11 @@ export abstract class GlBranchCardBase extends GlElement {
 		this.attachFocusListener();
 	}
 
-	get branchRefs() {
+	get branchRef(): BranchRef {
 		return {
 			repoPath: this.repo,
 			branchId: this.branch.id,
+			branchName: this.branch.name,
 		};
 	}
 
@@ -406,7 +428,7 @@ export abstract class GlBranchCardBase extends GlElement {
 		return getLaunchpadItemGrouping(getLaunchpadItemGroup(this.pr, this.launchpadItem)) ?? 'base';
 	}
 
-	get branchCardIndicator() {
+	get branchCardIndicator(): GlCard['indicator'] {
 		if (!this.branch.opened) return undefined;
 
 		if (this.wip?.pausedOpStatus != null) {
@@ -431,6 +453,10 @@ export abstract class GlBranchCardBase extends GlElement {
 			return 'branch-changes';
 		}
 
+		if (this.mergeTarget?.mergedStatus?.merged) {
+			return 'branch-merged';
+		}
+
 		switch (this.branch.status) {
 			case 'ahead':
 				return 'branch-ahead';
@@ -598,7 +624,7 @@ export abstract class GlBranchCardBase extends GlElement {
 	}
 
 	protected createCommandLink<T>(command: Commands, args?: T | any) {
-		return createCommandLink<T>(command, args ?? this.branchRefs);
+		return createCommandLink<T>(command, args ?? this.branchRef);
 	}
 
 	protected renderTimestamp() {
@@ -759,7 +785,7 @@ export abstract class GlBranchCardBase extends GlElement {
 
 		return html`<gl-merge-target-status
 			class="branch-item__merge-target"
-			.branch=${this.branch.name}
+			.branch=${this.branch}
 			.targetPromise=${this.branch.mergeTarget}
 		></gl-merge-target-status>`;
 	}
@@ -855,7 +881,7 @@ export class GlBranchCard extends GlBranchCardBase {
 				label="Open in Commit Graph"
 				icon="gl-graph"
 				href=${createCommandLink('gitlens.home.openInGraph', {
-					...this.branchRefs,
+					...this.branchRef,
 					type: 'branch',
 				} satisfies OpenInGraphParams)}
 			></action-item>`,