1 files changed, 33 insertions, 0 deletions
diff --git a/src/go/token/token_test.go b/src/go/token/token_test.go
new file mode 100644
index 0000000..eff38cc
--- /dev/null
+++ b/src/go/token/token_test.go
@@ -0,0 +1,33 @@
+// 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 token
+
+import "testing"
+
+func TestIsIdentifier(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want bool
+	}{
+		{"Empty", "", false},
+		{"Space", " ", false},
+		{"SpaceSuffix", "foo ", false},
+		{"Number", "123", false},
+		{"Keyword", "func", false},
+
+		{"LettersASCII", "foo", true},
+		{"MixedASCII", "_bar123", true},
+		{"UppercaseKeyword", "Func", true},
+		{"LettersUnicode", "fóö", true},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if got := IsIdentifier(test.in); got != test.want {
+				t.Fatalf("IsIdentifier(%q) = %t, want %v", test.in, got, test.want)
+			}
+		})
+	}
+}