Add hasUpstreamBranch method and auto-pull functionality when checking out branches with upstream

Author: zaknafeyn

src/commands/checkoutToCommand/index.ts

@@ -331,6 +331,9 @@ export class CheckoutToCommand extends BaseCommand {
       default:
         try {
           await git.checkout(newBranchName);
+          if (await git.hasUpstreamBranch(newBranchName)) {
+            await git.pullCurrentBranch();
+          }
         } catch (e) {
           throw new Error('Failed to checkout the selected branch.');
         }
@@ -363,6 +366,9 @@ export class CheckoutToCommand extends BaseCommand {
 
     try {
       await git.checkout(newBranch);
+      if (await git.hasUpstreamBranch(newBranch)) {
+        await git.pullCurrentBranch();
+      }
     } catch (e) {
       throw new Error('Failed to checkout the selected branch.');
     }
@@ -417,6 +423,9 @@ export class CheckoutToCommand extends BaseCommand {
     // Checkout the selected branch
     try {
       await git.checkout(newBranch);
+      if (await git.hasUpstreamBranch(newBranch)) {
+        await git.pullCurrentBranch();
+      }
     } catch (e) {
       throw new Error('Failed to checkout the selected branch.');
     }

src/common/git/gitExecutor.ts

@@ -464,6 +464,17 @@ export class GitExecutor {
     return await this.#checkRemoteBranchExists(branchName);
   }
 
+  async hasUpstreamBranch(branchName: string): Promise<boolean> {
+    const command = `git rev-parse --abbrev-ref ${branchName}@{upstream}`;
+
+    try {
+      await this.#execGitCommand(command);
+      return true;
+    } catch {
+      return false;
+    }
+  }
+
   async pushBranchToGitHub(branchName: string): Promise<void> {
     const command = `git push -u origin ${branchName}`;