migrations: add test for importing pull requests in gitea uploader (#18752)

* logs: add the buffer logger to inspect logs during testing

Signed-off-by: Loïc Dachary <loic@dachary.org>

* migrations: add test for importing pull requests in gitea uploader

Signed-off-by: Loïc Dachary <loic@dachary.org>

* for each git.OpenRepositoryCtx, call Close

* Content is expected to return the content of the log

* test for errors before defer

Co-authored-by: Loïc Dachary <loic@dachary.org>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

modules/log/buffer.go

@@ -0,0 +1,72 @@
+// Copyright 2022 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 log
+
+import (
+	"bytes"
+	"sync"
+)
+
+type bufferWriteCloser struct {
+	mu     sync.Mutex
+	buffer bytes.Buffer
+}
+
+func (b *bufferWriteCloser) Write(p []byte) (int, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	return b.buffer.Write(p)
+}
+
+func (b *bufferWriteCloser) Close() error {
+	return nil
+}
+
+func (b *bufferWriteCloser) String() string {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	return b.buffer.String()
+}
+
+// BufferLogger implements LoggerProvider and writes messages in a buffer.
+type BufferLogger struct {
+	WriterLogger
+}
+
+// NewBufferLogger create BufferLogger returning as LoggerProvider.
+func NewBufferLogger() LoggerProvider {
+	log := &BufferLogger{}
+	log.NewWriterLogger(&bufferWriteCloser{})
+	return log
+}
+
+// Init inits connection writer
+func (log *BufferLogger) Init(string) error {
+	log.NewWriterLogger(log.out)
+	return nil
+}
+
+// Content returns the content accumulated in the content provider
+func (log *BufferLogger) Content() (string, error) {
+	return log.out.(*bufferWriteCloser).String(), nil
+}
+
+// Flush when log should be flushed
+func (log *BufferLogger) Flush() {
+}
+
+// ReleaseReopen does nothing
+func (log *BufferLogger) ReleaseReopen() error {
+	return nil
+}
+
+// GetName returns the default name for this implementation
+func (log *BufferLogger) GetName() string {
+	return "buffer"
+}
+
+func init() {
+	Register("buffer", NewBufferLogger)
+}