1 files changed, 52 insertions, 0 deletions
diff --git a/compare_test.go b/compare_test.go
new file mode 100644
index 0000000..3922e2d
--- /dev/null
+++ b/compare_test.go
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ */
+
+package syntax
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func FuzzComparison(f *testing.F) {
+	corpus, err := filepath.Glob("./corpus/*.conf")
+	if err != nil {
+		f.Fatal(err)
+	}
+	for _, c := range corpus {
+		b, err := os.ReadFile(c)
+		if err != nil {
+			f.Fatal(err)
+		}
+		f.Logf("Adding %+q to corpus", c)
+		f.Add(string(b))
+	}
+	corpus, err = filepath.Glob("/etc/wireguard/*.conf")
+	if err == nil {
+		for _, c := range corpus {
+			b, err := os.ReadFile(c)
+			if err == nil {
+				f.Logf("Adding %+q to corpus", c)
+				f.Add(string(b))
+			}
+		}
+	}
+
+	f.Fuzz(func(t *testing.T, in string) {
+		in, _, _ = strings.Cut(in, "\x00")
+		goOutput := highlightConfig(in)
+		cOutput := highlightConfigC(in)
+		if len(goOutput) != len(cOutput) {
+			t.Fatalf("output length is not the same: %+v vs %+v: %+q", goOutput, cOutput, in)
+		}
+		for i := range goOutput {
+			if goOutput[i] != cOutput[i] {
+				t.Fatalf("struct return mismatch: %+v vs %+v: %+q", goOutput[i], cOutput[i], in)
+			}
+		}
+	})
+}