1 files changed, 44 insertions, 0 deletions
diff --git a/gopls/internal/lsp/general_test.go b/gopls/internal/lsp/general_test.go
new file mode 100644
index 000000000..a0312ba1b
--- /dev/null
+++ b/gopls/internal/lsp/general_test.go
@@ -0,0 +1,44 @@
+// Copyright 2022 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 lsp
+
+import (
+	"strings"
+	"testing"
+
+	"golang.org/x/tools/gopls/internal/lsp/protocol"
+)
+
+func TestVersionMessage(t *testing.T) {
+	tests := []struct {
+		goVersion    int
+		wantContains []string // string fragments that we expect to see
+		wantType     protocol.MessageType
+	}{
+		{-1, nil, 0},
+		{12, []string{"1.12", "not supported", "upgrade to Go 1.16", "install gopls v0.7.5"}, protocol.Error},
+		{13, []string{"1.13", "will be unsupported by gopls v0.11.0", "upgrade to Go 1.16", "install gopls v0.9.5"}, protocol.Warning},
+		{15, []string{"1.15", "will be unsupported by gopls v0.11.0", "upgrade to Go 1.16", "install gopls v0.9.5"}, protocol.Warning},
+		{16, nil, 0},
+	}
+
+	for _, test := range tests {
+		gotMsg, gotType := versionMessage(test.goVersion)
+
+		if len(test.wantContains) == 0 && gotMsg != "" {
+			t.Errorf("versionMessage(%d) = %q, want \"\"", test.goVersion, gotMsg)
+		}
+
+		for _, want := range test.wantContains {
+			if !strings.Contains(gotMsg, want) {
+				t.Errorf("versionMessage(%d) = %q, want containing %q", test.goVersion, gotMsg, want)
+			}
+		}
+
+		if gotType != test.wantType {
+			t.Errorf("versionMessage(%d) = returned message type %d, want %d", test.goVersion, gotType, test.wantType)
+		}
+	}
+}