25: 1000-digit fibonacci number

25_1000_digit_fibonacci_number/main_test.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"math/big"
+	"reflect"
+	"testing"
+)
+
+func Test_fibonacci(t *testing.T) {
+	type args struct {
+		index int
+	}
+	tt := []struct {
+		name string
+		args args
+		want *big.Int
+	}{
+		{
+			"1",
+			args{1},
+			(&big.Int{}).SetBits([]big.Word{1}),
+		},
+		{
+			"10",
+			args{10},
+			(&big.Int{}).SetBits([]big.Word{big.Word(55)}),
+		},
+		{
+			"12",
+			args{12},
+			(&big.Int{}).SetBits([]big.Word{big.Word(144)}),
+		},
+		{
+			"13",
+			args{13},
+			(&big.Int{}).SetBits([]big.Word{big.Word(233)}),
+		},
+	}
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := fibonacci(tc.args.index); !reflect.DeepEqual(got, tc.want) {
+				t.Errorf("fibonacci() = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}