1 files changed, 68 insertions, 0 deletions
diff --git a/custom_test.go b/custom_test.go
new file mode 100644
index 0000000..a8bdfe6
--- /dev/null
+++ b/custom_test.go
@@ -0,0 +1,68 @@
+package caesar
+
+import (
+	"bytes"
+	"flag"
+	"io"
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+var (
+	runCustom   bool
+	customCases string
+)
+
+func TestMain(m *testing.M) {
+	flag.BoolVar(&runCustom, "custom", false, "run custom tests")
+	flag.StringVar(&customCases, "custom.cases", "", "input file for custom test cases")
+	flag.Parse()
+	os.Exit(m.Run())
+}
+
+func TestCustom(t *testing.T) {
+	if !runCustom {
+		t.Skip("skipping custom testing")
+	}
+	f, err := os.Open(customCases)
+	if err != nil {
+		t.Fatalf("could not open custom test input: %v", err)
+	}
+	defer f.Close()
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		t.Fatalf("could not read custom test input: %v", err)
+	}
+	buf := bytes.NewBuffer(data)
+	for {
+		// read input
+		inp, err := buf.ReadBytes('\t')
+		if err == io.EOF {
+			return
+		} else if err != nil {
+			t.Fatalf("read error: %v", err)
+		}
+
+		// read expected output
+		exp, err := buf.ReadBytes('\n')
+		if err == io.EOF {
+			t.Fatalf("found input with no matching output")
+		} else if err != nil {
+			t.Fatalf("read error: %v", err)
+		}
+
+		if len(inp) < 2 || len(exp) < 2 {
+			t.Fatalf("malformed input")
+		}
+
+		result := Encode(string(inp[:len(inp)-2]))
+		if result != string(exp[:len(exp)-2]) {
+			t.Logf("input: %s", inp)
+			t.Logf("output: %s", result)
+			t.Logf("expected: %s", exp)
+			t.Fail()
+		}
+	}
+	Encode(string(data))
+}