add examples, fix bug

3 files changed, 59 insertions, 9 deletions

diff --git a/caesar.go b/caesar.go
index 191c5b8..4829e6a 100644
--- a/caesar.go
+++ b/caesar.go
@@ -26,9 +26,16 @@ func (rr RuneRange) contains(r rune) bool {
 	return r >= rr.Start && r <= rr.End
 }
 
+// size calculates the size of the range.
+func (rr RuneRange) size() int {
+	return int(rr.End-rr.Start) + 1
+}
+
 // shift shifts r by d within the range, modulo the size of the range.
 func (rr RuneRange) shift(r rune, d int) rune {
-	return rr.Start + (r - rr.Start + rune(d)%(rr.End-rr.Start))
+	pos := int(r - rr.Start)
+	newPos := (pos + d) % rr.size()
+	return rr.Start + rune(newPos)
 }
 
 // A Coder encodes and decodes Caesar cipher messages according to its key and
diff --git a/caesar_test.go b/caesar_test.go
index 04b853b..6a01f43 100644
--- a/caesar_test.go
+++ b/caesar_test.go
@@ -6,29 +6,72 @@ import (
 
 func TestEncode(t *testing.T) {
 	msg := "Attack at dawn"
+	t.Logf("testing message %s", msg)
 	if Encode(msg) != "Dwwdfn dw gdzq" {
 		t.Fail()
 	}
 }
 
-func TestCaesar(t *testing.T) {
+func TestLong(t *testing.T) {
 	if testing.Short() {
 		t.Skip()
 	}
 	msg := "Attack at dawn"
-	t.Logf("testing encoding message %s", msg)
 	encoded := Encode(msg)
 	if encoded == msg {
-		t.Log("expected ciphertext and plaintext to differ")
-		t.Fail()
+		t.Errorf("expected ciphertext and plaintext to differ")
 	}
 	decoded := Decode(encoded)
 	if decoded != msg {
-		t.Logf("expected recovered plaintext to match message, but got: %s", decoded)
-		t.Fail()
+		t.Errorf("expected recovered plaintext to match message, but got: %s", decoded)
 	}
 }
 
-func BenchmarkCaesar(b *testing.B) {
+func TestEncoderTable(t *testing.T) {
+	tests := []struct {
+		in  string
+		out string
+	}{
+		{"abcxyz", "defabc"},
+		{"ABCXYZ", "DEFABC"},
+		{"1234567890", "4567890123"},
+		{"!@#$%^&*()", "!@#$%^&*()"},
+	}
+	for _, test := range tests {
+		result := Encode(test.in)
+		if result != test.out {
+			t.Errorf("encode %s: expected %s, got %s", test.in, test.out, result)
+		}
+	}
+}
+
+func TestEncoderIndividualTable(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		out  string
+	}{
+		{"lowers", "abcxyz", "defabc"},
+		{"uppers", "ABCXYZ", "DEFABC"},
+		{"nums", "1234567890", "4567890123"},
+		{"symbols", "!@#$%^&*()", "!@#$%^&*()"},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			result := Encode(test.in)
+			if result != test.out {
+				t.Fatalf("expected %s, got %s", test.out, result) // HL
+			}
+		})
+	}
+}
+
+func BenchmarkFailure(b *testing.B) {
 	b.Fail()
 }
+
+func BenchmarkEncode(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		Encode("attack at dawn")
+	}
+}
diff --git a/client/client_test.go b/client/client_test.go
index fb1701c..b4a1b2a 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -48,7 +48,7 @@ func TestEncode(t *testing.T) {
 	}
 	server := httptest.NewServer(hf)
 	defer server.Close()
-	c := CaesarClient{Endpoint: server.URL}
+	c := CaesarClient{Endpoint: server.URL} // HL
 	r, err := c.EncodeMessage(strings.NewReader("secret message"))
 	if err != nil {
 		t.Errorf("should not have gotten error: %v", err)