Add missing forked gateway tests (#5118)

* Add missing tests for `storegateway`.

* Fork cortex tsdb testutil package.

* Fix import lint.

pkg/storage/tsdb/testutil/block_mock.go

@@ -0,0 +1,68 @@
+package testutil
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/json"
+	"fmt"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/oklog/ulid"
+	"github.com/prometheus/prometheus/tsdb"
+	"github.com/stretchr/testify/require"
+	"github.com/thanos-io/thanos/pkg/block/metadata"
+	"github.com/thanos-io/thanos/pkg/objstore"
+)
+
+func MockStorageBlock(t testing.TB, bucket objstore.Bucket, userID string, minT, maxT int64) tsdb.BlockMeta {
+	// Generate a block ID whose timestamp matches the maxT (for simplicity we assume it
+	// has been compacted and shipped in zero time, even if not realistic).
+	id := ulid.MustNew(uint64(maxT), rand.Reader)
+
+	meta := tsdb.BlockMeta{
+		Version: 1,
+		ULID:    id,
+		MinTime: minT,
+		MaxTime: maxT,
+		Compaction: tsdb.BlockMetaCompaction{
+			Level:   1,
+			Sources: []ulid.ULID{id},
+		},
+	}
+
+	metaContent, err := json.Marshal(meta)
+	if err != nil {
+		panic("failed to marshal mocked block meta")
+	}
+
+	metaContentReader := strings.NewReader(string(metaContent))
+	metaPath := fmt.Sprintf("%s/%s/meta.json", userID, id.String())
+	require.NoError(t, bucket.Upload(context.Background(), metaPath, metaContentReader))
+
+	// Upload an empty index, just to make sure the meta.json is not the only object in the block location.
+	indexPath := fmt.Sprintf("%s/%s/index", userID, id.String())
+	require.NoError(t, bucket.Upload(context.Background(), indexPath, strings.NewReader("")))
+
+	return meta
+}
+
+func MockStorageDeletionMark(t testing.TB, bucket objstore.Bucket, userID string, meta tsdb.BlockMeta) *metadata.DeletionMark {
+	mark := metadata.DeletionMark{
+		ID:           meta.ULID,
+		DeletionTime: time.Now().Add(-time.Minute).Unix(),
+		Version:      metadata.DeletionMarkVersion1,
+	}
+
+	markContent, err := json.Marshal(mark)
+	if err != nil {
+		panic("failed to marshal mocked block meta")
+	}
+
+	markContentReader := strings.NewReader(string(markContent))
+	markPath := fmt.Sprintf("%s/%s/%s", userID, meta.ULID.String(), metadata.DeletionMarkFilename)
+	require.NoError(t, bucket.Upload(context.Background(), markPath, markContentReader))
+
+	return &mark
+}

pkg/storage/tsdb/testutil/objstore.go

@@ -0,0 +1,26 @@
+package testutil
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/thanos-io/thanos/pkg/objstore"
+
+	"github.com/cortexproject/cortex/pkg/storage/bucket/filesystem"
+)
+
+func PrepareFilesystemBucket(t testing.TB) (objstore.Bucket, string) {
+	storageDir, err := ioutil.TempDir(os.TempDir(), "bucket")
+	require.NoError(t, err)
+
+	t.Cleanup(func() {
+		require.NoError(t, os.RemoveAll(storageDir))
+	})
+
+	bkt, err := filesystem.NewBucketClient(filesystem.Config{Directory: storageDir})
+	require.NoError(t, err)
+
+	return objstore.BucketWithMetrics("test", bkt, nil), storageDir
+}