Improve migrations to support migrating milestones/labels/issues/comments/pullrequests (#6290)

* add migrations

* fix package dependency

* fix lints

* implements migrations except pull requests

* add releases

* migrating releases

* fix bug

* fix lint

* fix migrate releases

* fix tests

* add rollback

* pull request migtations

* fix import

* fix go module vendor

* add tests for upload to gitea

* more migrate options

* fix swagger-check

* fix misspell

* add options on migration UI

* fix log error

* improve UI options on migrating

* add support for username password when migrating from github

* fix tests

* remove comments and fix migrate limitation

* improve error handles

* migrate API will also support migrate milestones/labels/issues/pulls/releases

* fix tests and remove unused codes

* add DownloaderFactory and docs about how to create a new Downloader

* fix misspell

* fix migration docs

* Add hints about migrate options on migration page

* fix tests

1 files changed, 29 insertions, 0 deletions

diff --git a/modules/migrations/error.go b/modules/migrations/error.go
new file mode 100644
index 0000000000..a48484d156
--- /dev/null
+++ b/modules/migrations/error.go
@@ -0,0 +1,29 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Copyright 2018 Jonas Franz. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package migrations
+
+import (
+	"errors"
+
+	"github.com/google/go-github/v24/github"
+)
+
+var (
+	// ErrNotSupported returns the error not supported
+	ErrNotSupported = errors.New("not supported")
+)
+
+// IsRateLimitError returns true if the err is github.RateLimitError
+func IsRateLimitError(err error) bool {
+	_, ok := err.(*github.RateLimitError)
+	return ok
+}
+
+// IsTwoFactorAuthError returns true if the err is github.TwoFactorAuthError
+func IsTwoFactorAuthError(err error) bool {
+	_, ok := err.(*github.TwoFactorAuthError)
+	return ok
+}