1 files changed, 36 insertions, 0 deletions
diff --git a/lib/error_test.go b/lib/error_test.go
new file mode 100644
index 00000000..d73b1ec8
--- /dev/null
+++ b/lib/error_test.go
@@ -0,0 +1,36 @@
+package lib
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestErrors(t *testing.T) {
+	tests := []struct {
+		name string
+		err  error
+	}{
+		{"ErrDuplicatedConverter", ErrDuplicatedConverter},
+		{"ErrUnknownAction", ErrUnknownAction},
+		{"ErrNotSupportedFormat", ErrNotSupportedFormat},
+		{"ErrInvalidIPType", ErrInvalidIPType},
+		{"ErrInvalidIP", ErrInvalidIP},
+		{"ErrInvalidIPLength", ErrInvalidIPLength},
+		{"ErrInvalidIPNet", ErrInvalidIPNet},
+		{"ErrInvalidCIDR", ErrInvalidCIDR},
+		{"ErrInvalidPrefix", ErrInvalidPrefix},
+		{"ErrInvalidPrefixType", ErrInvalidPrefixType},
+		{"ErrCommentLine", ErrCommentLine},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.err == nil {
+				t.Errorf("%s should not be nil", tt.name)
+			}
+			if !errors.Is(tt.err, tt.err) {
+				t.Errorf("%s should match itself", tt.name)
+			}
+		})
+	}
+}