test: add example for mathutil package

mathutil/mathutil_exmaple_test.go

@@ -0,0 +1,187 @@
+package mathutil
+
+import "fmt"
+
+func ExampleExponent() {
+	result1 := Exponent(10, 0)
+	result2 := Exponent(10, 1)
+	result3 := Exponent(10, 2)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// 1
+	// 10
+	// 100
+}
+
+func ExampleFibonacci() {
+	result1 := Fibonacci(1, 1, 1)
+	result2 := Fibonacci(1, 1, 2)
+	result3 := Fibonacci(1, 1, 5)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// 1
+	// 1
+	// 5
+}
+
+func ExampleFactorial() {
+	result1 := Factorial(1)
+	result2 := Factorial(2)
+	result3 := Factorial(3)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// 1
+	// 2
+	// 6
+}
+
+func ExamplePercent() {
+	result1 := Percent(1, 2, 2)
+	result2 := Percent(0.1, 0.3, 2)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// 0.5
+	// 0.33
+}
+
+func ExampleRoundToFloat() {
+	result1 := RoundToFloat(0.124, 2)
+	result2 := RoundToFloat(0.125, 2)
+	result3 := RoundToFloat(0.125, 3)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// 0.12
+	// 0.13
+	// 0.125
+}
+
+func ExampleRoundToString() {
+	result1 := RoundToString(0.124, 2)
+	result2 := RoundToString(0.125, 2)
+	result3 := RoundToString(0.125, 3)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// 0.12
+	// 0.13
+	// 0.125
+}
+
+func ExampleTruncRound() {
+	result1 := TruncRound(0.124, 2)
+	result2 := TruncRound(0.125, 2)
+	result3 := TruncRound(0.125, 3)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// 0.12
+	// 0.12
+	// 0.125
+}
+
+func ExampleAverage() {
+	result1 := Average(1, 2)
+	result2 := RoundToFloat(Average(1.2, 1.4), 1)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// 1
+	// 1.3
+}
+
+func ExampleMax() {
+	result1 := Max(1, 2, 3)
+	result2 := Max(1.2, 1.4, 1.1, 1.4)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// 3
+	// 1.4
+}
+
+func ExampleMaxBy() {
+	result1 := MaxBy([]string{"a", "ab", "abc"}, func(v1, v2 string) bool {
+		return len(v1) > len(v2)
+	})
+
+	result2 := MaxBy([]string{"abd", "abc", "ab"}, func(v1, v2 string) bool {
+		return len(v1) > len(v2)
+	})
+
+	result3 := MaxBy([]string{}, func(v1, v2 string) bool {
+		return len(v1) > len(v2)
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// abc
+	// abd
+	//
+}
+
+func ExampleMin() {
+	result1 := Min(1, 2, 3)
+	result2 := Min(1.2, 1.4, 1.1, 1.4)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// 1
+	// 1.1
+}
+
+func ExampleMinBy() {
+	result1 := MinBy([]string{"a", "ab", "abc"}, func(v1, v2 string) bool {
+		return len(v1) < len(v2)
+	})
+
+	result2 := MinBy([]string{"ab", "ac", "abc"}, func(v1, v2 string) bool {
+		return len(v1) < len(v2)
+	})
+
+	result3 := MinBy([]string{}, func(v1, v2 string) bool {
+		return len(v1) < len(v2)
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// a
+	// ab
+	//
+}