add test for polybius(coverage: 100%)

checked with "go test -covermode=atomic ./..."

Author: task4233

ciphers/polybius/polybius_test.go

@@ -0,0 +1,121 @@
+package polybius_test
+
+import (
+	"TheAlgorithms/Go/ciphers/polybius"
+	"testing"
+)
+
+func TestNewPolybius(t *testing.T) {
+	t.Parallel()
+	cases := []struct {
+		name       string
+		size       int
+		characters string
+		key        string
+		wantErr    string
+	}{
+		{
+			name: "correct initalization", size: 5, characters: "HogeF", key: "abcdefghijklmnopqrstuvwxy", wantErr: "",
+		},
+		{
+			name: "truncate characters", size: 5, characters: "HogeFuga", key: "abcdefghijklmnopqrstuvwxy", wantErr: "",
+		},
+		{
+			name: "invaid key", size: 5, characters: "HogeFuga", key: "abcdefghi", wantErr: "len(key): 9 must be as long as size squared: 25",
+		},
+		{
+			name: "invalid characters", size: 5, characters: "HogeH", key: "abcdefghijklmnopqrstuvwxy", wantErr: "\"chars\" contains same character: H",
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			_, err := polybius.NewPolybius(tc.key, tc.size, tc.characters)
+			if err != nil && err.Error() != tc.wantErr {
+				t.Errorf("failed NewPolybius: %v", err)
+			}
+		})
+	}
+}
+
+func TestPolybiusEncrypt(t *testing.T) {
+	t.Parallel()
+	cases := []struct {
+		name string
+		text string
+		want string
+	}{
+		{
+			name: "correct encryption", text: "hoge", want: "OGGFOOHF",
+		},
+		{
+			name: "invalid encryption", text: "hogz", want: "failed encipher: Z does not exist in keys",
+		},
+	}
+	// initialize
+	const (
+		size       = 5
+		characters = "HogeFuga"
+		key        = "abcdefghijklmnopqrstuvwxy"
+	)
+	p, err := polybius.NewPolybius(key, size, characters)
+	if err != nil {
+		t.Fatalf("failed NewPolybius: %v", err)
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			encrypted, err := p.Encrypt(tc.text)
+			if err != nil {
+				if err.Error() != tc.want {
+					t.Errorf("failed Encrypt: %v", err)
+				}
+			} else if encrypted != tc.want {
+				t.Errorf("Encrypt: %v, want: %v", encrypted, tc.want)
+			}
+		})
+	}
+}
+
+func TestPolybiusDecrypt(t *testing.T) {
+	t.Parallel()
+	cases := []struct {
+		name string
+		text string
+		want string
+	}{
+		{
+			name: "correct decryption", text: "OGGFOOHF", want: "HOGE",
+		},
+		{
+			name: "invalid decryption(position of even number)", text: "hogz", want: "failed decipher: Z does not exist in characters",
+		},
+		{
+			name: "invalid decryption(position of odd number)", text: "hode", want: "failed decipher: D does not exist in characters",
+		},
+		{
+			name: "invalid text size which is odd", text: "hog", want: "failed decipher: the size of \"chars\" must be even",
+		},
+	}
+	// initialize
+	const (
+		size       = 5
+		characters = "HogeF"
+		key        = "abcdefghijklmnopqrstuvwxy"
+	)
+	p, err := polybius.NewPolybius(key, size, characters)
+	if err != nil {
+		t.Fatalf("failed NewPolybius: %v", err)
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			encrypted, err := p.Decrypt(tc.text)
+			if err != nil {
+				if err.Error() != tc.want {
+					t.Errorf("failed Encrypt: %v", err)
+				}
+			} else if encrypted != tc.want {
+				t.Errorf("Encrypt: %v, want: %v", encrypted, tc.want)
+			}
+		})
+	}
+}