[Refactor] move pull checkout & clean code into task module (#249)

Merge branch 'master' into refactor_checkout2task

move pull clean code into task module

fix lint

format code

unify PullCheckout() and gitConfigForPR()

move pull checkout code into task module

Co-authored-by: 6543 <6543@noreply.gitea.io>
Reviewed-on: https://gitea.com/gitea/tea/pulls/249
Reviewed-by: Norwin <noerw@noreply.gitea.io>
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-Authored-By: 6543 <6543@obermui.de>
Co-Committed-By: 6543 <6543@obermui.de>

modules/task/pull_clean.go

@@ -0,0 +1,86 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package task
+
+import (
+	"fmt"
+
+	"code.gitea.io/sdk/gitea"
+	"code.gitea.io/tea/modules/config"
+	local_git "code.gitea.io/tea/modules/git"
+
+	git_config "github.com/go-git/go-git/v5/config"
+)
+
+// PullClean deletes local & remote feature-branches for a closed pull
+func PullClean(login *config.Login, repoOwner, repoName string, index int64, ignoreSHA bool) error {
+	client := login.Client()
+
+	repo, _, err := client.GetRepo(repoOwner, repoName)
+	defaultBranch := repo.DefaultBranch
+	if len(defaultBranch) == 0 {
+		defaultBranch = "master"
+	}
+
+	// fetch PR source-repo & -branch from gitea
+	pr, _, err := client.GetPullRequest(repoOwner, repoName, index)
+	if err != nil {
+		return err
+	}
+	if pr.State == gitea.StateOpen {
+		return fmt.Errorf("PR is still open, won't delete branches")
+	}
+
+	// IDEA: abort if PR.Head.Repository.CloneURL does not match login.URL?
+
+	r, err := local_git.RepoForWorkdir()
+	if err != nil {
+		return err
+	}
+
+	// find a branch with matching sha or name, that has a remote matching the repo url
+	var branch *git_config.Branch
+	if ignoreSHA {
+		branch, err = r.TeaFindBranchByName(pr.Head.Ref, pr.Head.Repository.CloneURL)
+	} else {
+		branch, err = r.TeaFindBranchBySha(pr.Head.Sha, pr.Head.Repository.CloneURL)
+	}
+	if err != nil {
+		return err
+	}
+	if branch == nil {
+		if ignoreSHA {
+			return fmt.Errorf("Remote branch %s not found in local repo", pr.Head.Ref)
+		}
+		return fmt.Errorf(`Remote branch %s not found in local repo.
+Either you don't track this PR, or the local branch has diverged from the remote.
+If you still want to continue & are sure you don't loose any important commits,
+call me again with the --ignore-sha flag`, pr.Head.Ref)
+	}
+
+	// prepare deletion of local branch:
+	headRef, err := r.Head()
+	if err != nil {
+		return err
+	}
+	if headRef.Name().Short() == branch.Name {
+		fmt.Printf("Checking out '%s' to delete local branch '%s'\n", defaultBranch, branch.Name)
+		if err = r.TeaCheckout(defaultBranch); err != nil {
+			return err
+		}
+	}
+
+	// remove local & remote branch
+	fmt.Printf("Deleting local branch %s and remote branch %s\n", branch.Name, pr.Head.Ref)
+	url, err := r.TeaRemoteURL(branch.Remote)
+	if err != nil {
+		return err
+	}
+	auth, err := local_git.GetAuthForURL(url, login.User, login.SSHKey)
+	if err != nil {
+		return err
+	}
+	return r.TeaDeleteBranch(branch, pr.Head.Ref, auth)
+}