Use the type RefName for all the needed places and fix pull mirror sync bugs (#24634)

This PR replaces all string refName as a type `git.RefName` to make the
code more maintainable.

Fix #15367
Replaces #23070 
It also fixed a bug that tags are not sync because `git remote --prune
origin` will not remove local tags if remote removed.

We in fact should use `git fetch --prune --tags origin` but not `git
remote update origin` to do the sync.

Some answer from ChatGPT as ref.

> If the git fetch --prune --tags command is not working as expected,
there could be a few reasons why. Here are a few things to check:
> 
>Make sure that you have the latest version of Git installed on your
system. You can check the version by running git --version in your
terminal. If you have an outdated version, try updating Git and see if
that resolves the issue.
> 
>Check that your Git repository is properly configured to track the
remote repository's tags. You can check this by running git config
--get-all remote.origin.fetch and verifying that it includes
+refs/tags/*:refs/tags/*. If it does not, you can add it by running git
config --add remote.origin.fetch "+refs/tags/*:refs/tags/*".
> 
>Verify that the tags you are trying to prune actually exist on the
remote repository. You can do this by running git ls-remote --tags
origin to list all the tags on the remote repository.
> 
>Check if any local tags have been created that match the names of tags
on the remote repository. If so, these local tags may be preventing the
git fetch --prune --tags command from working properly. You can delete
local tags using the git tag -d command.

---------

Co-authored-by: delvh <dev.lh@web.de>

1 files changed, 46 insertions, 0 deletions

diff --git a/services/mirror/mirror_test.go b/services/mirror/mirror_test.go
new file mode 100644
index 0000000000..8ad524b608
--- /dev/null
+++ b/services/mirror/mirror_test.go
@@ -0,0 +1,46 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package mirror
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_parseRemoteUpdateOutput(t *testing.T) {
+	output := `
+ * [new tag]         v0.1.8     -> v0.1.8
+ * [new branch]      master     -> origin/master
+ - [deleted]         (none)     -> origin/test1
+ - [deleted]         (none)     -> tag1
+ + f895a1e...957a993 test2      -> origin/test2  (forced update)
+   957a993..a87ba5f  test3      -> origin/test3
+`
+	results := parseRemoteUpdateOutput(output, "origin")
+	assert.Len(t, results, 6)
+	assert.EqualValues(t, "refs/tags/v0.1.8", results[0].refName.String())
+	assert.EqualValues(t, gitShortEmptySha, results[0].oldCommitID)
+	assert.EqualValues(t, "", results[0].newCommitID)
+
+	assert.EqualValues(t, "refs/heads/master", results[1].refName.String())
+	assert.EqualValues(t, gitShortEmptySha, results[1].oldCommitID)
+	assert.EqualValues(t, "", results[1].newCommitID)
+
+	assert.EqualValues(t, "refs/heads/test1", results[2].refName.String())
+	assert.EqualValues(t, "", results[2].oldCommitID)
+	assert.EqualValues(t, gitShortEmptySha, results[2].newCommitID)
+
+	assert.EqualValues(t, "refs/tags/tag1", results[3].refName.String())
+	assert.EqualValues(t, "", results[3].oldCommitID)
+	assert.EqualValues(t, gitShortEmptySha, results[3].newCommitID)
+
+	assert.EqualValues(t, "refs/heads/test2", results[4].refName.String())
+	assert.EqualValues(t, "f895a1e", results[4].oldCommitID)
+	assert.EqualValues(t, "957a993", results[4].newCommitID)
+
+	assert.EqualValues(t, "refs/heads/test3", results[5].refName.String())
+	assert.EqualValues(t, "957a993", results[5].oldCommitID)
+	assert.EqualValues(t, "a87ba5f", results[5].newCommitID)
+}