1 files changed, 73 insertions, 0 deletions
diff --git a/gopls/internal/lsp/cmd/folding_range.go b/gopls/internal/lsp/cmd/folding_range.go
new file mode 100644
index 000000000..68d93a3fb
--- /dev/null
+++ b/gopls/internal/lsp/cmd/folding_range.go
@@ -0,0 +1,73 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cmd
+
+import (
+	"context"
+	"flag"
+	"fmt"
+
+	"golang.org/x/tools/gopls/internal/lsp/protocol"
+	"golang.org/x/tools/gopls/internal/span"
+	"golang.org/x/tools/internal/tool"
+)
+
+// foldingRanges implements the folding_ranges verb for gopls
+type foldingRanges struct {
+	app *Application
+}
+
+func (r *foldingRanges) Name() string      { return "folding_ranges" }
+func (r *foldingRanges) Parent() string    { return r.app.Name() }
+func (r *foldingRanges) Usage() string     { return "<file>" }
+func (r *foldingRanges) ShortHelp() string { return "display selected file's folding ranges" }
+func (r *foldingRanges) DetailedHelp(f *flag.FlagSet) {
+	fmt.Fprint(f.Output(), `
+Example:
+
+	$ gopls folding_ranges helper/helper.go
+`)
+	printFlagDefaults(f)
+}
+
+func (r *foldingRanges) Run(ctx context.Context, args ...string) error {
+	if len(args) != 1 {
+		return tool.CommandLineErrorf("folding_ranges expects 1 argument (file)")
+	}
+
+	conn, err := r.app.connect(ctx)
+	if err != nil {
+		return err
+	}
+	defer conn.terminate(ctx)
+
+	from := span.Parse(args[0])
+	file := conn.openFile(ctx, from.URI())
+	if file.err != nil {
+		return file.err
+	}
+
+	p := protocol.FoldingRangeParams{
+		TextDocument: protocol.TextDocumentIdentifier{
+			URI: protocol.URIFromSpanURI(from.URI()),
+		},
+	}
+
+	ranges, err := conn.FoldingRange(ctx, &p)
+	if err != nil {
+		return err
+	}
+
+	for _, r := range ranges {
+		fmt.Printf("%v:%v-%v:%v\n",
+			r.StartLine+1,
+			r.StartCharacter+1,
+			r.EndLine+1,
+			r.EndCharacter+1,
+		)
+	}
+
+	return nil
+}