Add LSP rename/formatting tests (#4264)

Author: stefanvanburen

private/buf/buflsp/format_test.go

@@ -0,0 +1,89 @@
+// Copyright 2020-2025 Buf Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package buflsp_test
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+
+	"github.com/bufbuild/buf/private/buf/bufformat"
+	"github.com/bufbuild/buf/private/pkg/storage"
+	"github.com/bufbuild/buf/private/pkg/storage/storageos"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.lsp.dev/protocol"
+)
+
+func TestFormatting(t *testing.T) {
+	t.Parallel()
+
+	ctx := t.Context()
+
+	tests := []struct {
+		name           string
+		protoFile      string
+		expectEdits    bool
+		expectNumEdits int
+	}{
+		{
+			name:           "format_unformatted_file",
+			protoFile:      "unformatted.proto",
+			expectEdits:    true,
+			expectNumEdits: 1,
+		},
+		{
+			name:           "format_already_formatted_file",
+			protoFile:      "formatted.proto",
+			expectEdits:    false,
+			expectNumEdits: 0,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			testProtoPath, err := filepath.Abs(filepath.Join("testdata/format", tt.protoFile))
+			require.NoError(t, err)
+			clientJSONConn, testURI := setupLSPServer(t, testProtoPath)
+			var textEdits []protocol.TextEdit
+			_, formatErr := clientJSONConn.Call(ctx, protocol.MethodTextDocumentFormatting, protocol.DocumentFormattingParams{
+				TextDocument: protocol.TextDocumentIdentifier{
+					URI: testURI,
+				},
+			}, &textEdits)
+			require.NoError(t, formatErr)
+			assert.Len(t, textEdits, tt.expectNumEdits)
+			if tt.expectEdits {
+				expectedFormatted := getExpectedFormattedContent(t, ctx, testProtoPath)
+				assert.Equal(t, expectedFormatted, textEdits[0].NewText)
+				assert.Equal(t, uint32(0), textEdits[0].Range.Start.Line)
+				assert.Equal(t, uint32(0), textEdits[0].Range.Start.Character)
+			}
+		})
+	}
+}
+
+func getExpectedFormattedContent(t *testing.T, ctx context.Context, protoPath string) string {
+	t.Helper()
+	dir := filepath.Dir(protoPath)
+	bucket, err := storageos.NewProvider().NewReadWriteBucket(dir)
+	require.NoError(t, err)
+	formattedBucket, err := bufformat.FormatBucket(ctx, bucket)
+	require.NoError(t, err)
+	formatted, err := storage.ReadPath(ctx, formattedBucket, filepath.Base(protoPath))
+	require.NoError(t, err)
+	return string(formatted)
+}