diff --git a/gopls/test/gopls_test.go b/gopls/test/gopls_test.go
index e074b0c556..feceea3d9a 100644
--- a/gopls/test/gopls_test.go
+++ b/gopls/test/gopls_test.go
@@ -10,13 +10,8 @@ import (
 
 	"golang.org/x/tools/go/packages/packagestest"
 	"golang.org/x/tools/gopls/internal/hooks"
-	"golang.org/x/tools/internal/jsonrpc2/servertest"
-	"golang.org/x/tools/internal/lsp/cache"
 	cmdtest "golang.org/x/tools/internal/lsp/cmd/test"
-	"golang.org/x/tools/internal/lsp/debug"
-	"golang.org/x/tools/internal/lsp/lsprpc"
 	"golang.org/x/tools/internal/lsp/source"
-	"golang.org/x/tools/internal/lsp/tests"
 	"golang.org/x/tools/internal/testenv"
 )
 
@@ -26,7 +21,12 @@ func TestMain(m *testing.M) {
 }
 
 func TestCommandLine(t *testing.T) {
-	packagestest.TestAll(t, testCommandLine)
+	packagestest.TestAll(t,
+		cmdtest.TestCommandLine(
+			"../../internal/lsp/testdata",
+			commandLineOptions,
+		),
+	)
 }
 
 func commandLineOptions(options *source.Options) {
@@ -34,23 +34,3 @@ func commandLineOptions(options *source.Options) {
 	options.GoDiff = false
 	hooks.Options(options)
 }
-
-func testCommandLine(t *testing.T, exporter packagestest.Exporter) {
-	const testdata = "../../internal/lsp/testdata"
-	if stat, err := os.Stat(testdata); err != nil || !stat.IsDir() {
-		t.Skip("testdata directory not present")
-	}
-	data := tests.Load(t, exporter, testdata)
-	ctx := tests.Context(t)
-	ctx = debug.WithInstance(ctx, "", "")
-	cache := cache.New(ctx, commandLineOptions)
-	ss := lsprpc.NewStreamServer(cache)
-	ts := servertest.NewTCPServer(ctx, ss)
-	for _, data := range data {
-		defer data.Exported.Cleanup()
-		t.Run(data.Folder, func(t *testing.T) {
-			t.Helper()
-			tests.Run(t, cmdtest.NewRunner(exporter, data, tests.Context(t), ts.Addr, commandLineOptions), data)
-		})
-	}
-}
diff --git a/internal/lsp/cmd/cmd_test.go b/internal/lsp/cmd/cmd_test.go
index 0f0ca86e10..be054954a2 100644
--- a/internal/lsp/cmd/cmd_test.go
+++ b/internal/lsp/cmd/cmd_test.go
@@ -5,7 +5,6 @@
 package cmd_test
 
 import (
-	"context"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -14,12 +13,8 @@ import (
 	"testing"
 
 	"golang.org/x/tools/go/packages/packagestest"
-	"golang.org/x/tools/internal/jsonrpc2/servertest"
-	"golang.org/x/tools/internal/lsp/cache"
 	"golang.org/x/tools/internal/lsp/cmd"
 	cmdtest "golang.org/x/tools/internal/lsp/cmd/test"
-	"golang.org/x/tools/internal/lsp/debug"
-	"golang.org/x/tools/internal/lsp/lsprpc"
 	"golang.org/x/tools/internal/lsp/tests"
 	"golang.org/x/tools/internal/testenv"
 )
@@ -30,27 +25,12 @@ func TestMain(m *testing.M) {
 }
 
 func TestCommandLine(t *testing.T) {
-	packagestest.TestAll(t, testCommandLine)
-}
-
-func testCommandLine(t *testing.T, exporter packagestest.Exporter) {
-	ctx := tests.Context(t)
-	ts := testServer(ctx)
-	data := tests.Load(t, exporter, "../testdata")
-	for _, datum := range data {
-		defer datum.Exported.Cleanup()
-		t.Run(tests.FormatFolderName(datum.Folder), func(t *testing.T) {
-			t.Helper()
-			tests.Run(t, cmdtest.NewRunner(exporter, datum, ctx, ts.Addr, nil), datum)
-		})
-	}
-}
-
-func testServer(ctx context.Context) *servertest.TCPServer {
-	ctx = debug.WithInstance(ctx, "", "")
-	cache := cache.New(ctx, nil)
-	ss := lsprpc.NewStreamServer(cache)
-	return servertest.NewTCPServer(ctx, ss)
+	packagestest.TestAll(t,
+		cmdtest.TestCommandLine(
+			"../testdata",
+			nil,
+		),
+	)
 }
 
 func TestDefinitionHelpExample(t *testing.T) {
@@ -65,7 +45,7 @@ func TestDefinitionHelpExample(t *testing.T) {
 		return
 	}
 	ctx := tests.Context(t)
-	ts := testServer(ctx)
+	ts := cmdtest.NewTestServer(ctx, nil)
 	thisFile := filepath.Join(dir, "definition.go")
 	baseArgs := []string{"query", "definition"}
 	expect := regexp.MustCompile(`(?s)^[\w/\\:_-]+flag[/\\]flag.go:\d+:\d+-\d+: defined here as FlagSet struct {.*}$`)
diff --git a/internal/lsp/cmd/test/cmdtest.go b/internal/lsp/cmd/test/cmdtest.go
index a1bff9bfd7..863e7edb02 100644
--- a/internal/lsp/cmd/test/cmdtest.go
+++ b/internal/lsp/cmd/test/cmdtest.go
@@ -18,7 +18,11 @@ import (
 	"testing"
 
 	"golang.org/x/tools/go/packages/packagestest"
+	"golang.org/x/tools/internal/jsonrpc2/servertest"
+	"golang.org/x/tools/internal/lsp/cache"
 	"golang.org/x/tools/internal/lsp/cmd"
+	"golang.org/x/tools/internal/lsp/debug"
+	"golang.org/x/tools/internal/lsp/lsprpc"
 	"golang.org/x/tools/internal/lsp/protocol"
 	"golang.org/x/tools/internal/lsp/source"
 	"golang.org/x/tools/internal/lsp/tests"
@@ -42,6 +46,31 @@ type normalizer struct {
 	fragment string
 }
 
+func TestCommandLine(testdata string, options func(*source.Options)) func(*testing.T, packagestest.Exporter) {
+	return func(t *testing.T, exporter packagestest.Exporter) {
+		if stat, err := os.Stat(testdata); err != nil || !stat.IsDir() {
+			t.Skip("testdata directory not present")
+		}
+		ctx := tests.Context(t)
+		ts := NewTestServer(ctx, options)
+		data := tests.Load(t, exporter, testdata)
+		for _, datum := range data {
+			defer datum.Exported.Cleanup()
+			t.Run(tests.FormatFolderName(datum.Folder), func(t *testing.T) {
+				t.Helper()
+				tests.Run(t, NewRunner(exporter, datum, ctx, ts.Addr, options), datum)
+			})
+		}
+	}
+}
+
+func NewTestServer(ctx context.Context, options func(*source.Options)) *servertest.TCPServer {
+	ctx = debug.WithInstance(ctx, "", "")
+	cache := cache.New(ctx, options)
+	ss := lsprpc.NewStreamServer(cache)
+	return servertest.NewTCPServer(ctx, ss)
+}
+
 func NewRunner(exporter packagestest.Exporter, data *tests.Data, ctx context.Context, remote string, options func(*source.Options)) *runner {
 	r := &runner{
 		exporter:    exporter,