Merge pull request #3 from burrelle/test/refactor

Refactor to be able to unit test

main.go

@@ -8,25 +8,34 @@ import (
 	"time"
 )
 
-func main() {
-
-	args := os.Args[1:]
-
+func readArguments(args []string) (int64, int64) {
 	percentageLoad, err := strconv.ParseInt(args[0], 10, 64)
 	if err != nil {
 		fmt.Println("Invalid percentage load")
+		percentageLoad = 0
 	}
-
 	secondsToRun, err := strconv.ParseInt(args[1], 10, 64)
 	if err != nil {
 		fmt.Println("Invalid seconds to run")
+		secondsToRun = 0
 	}
+	return percentageLoad, secondsToRun
+}
+
+func calcuatePercentage(percentageLoad int64) float64 {
+	return float64((float64(percentageLoad) / 100.0))
+}
 
-	var percentage float64 = float64((float64(percentageLoad) / 100.0))
-	var cpuCount float64 = float64(runtime.NumCPU()) * percentage
+func calcuateCPUCount(percentage float64, CPU int) float64 {
+	return float64(CPU) * percentage
+}
+
+func outputLoadAndCount(cpuCount, percentage float64, percentageLoad int64) {
 	fmt.Println(fmt.Sprintf("%v * ( %v / %v ) = %v", runtime.NumCPU(), percentageLoad, 100, cpuCount))
 	fmt.Println(fmt.Sprintf("%v * %v = %v", runtime.NumCPU(), percentage, cpuCount))
+}
 
+func troll(cpuCount float64, secondsToRun int64) {
 	done := make(chan int)
 
 	for i := 0; i < int(cpuCount); i++ {
@@ -44,3 +53,12 @@ func main() {
 	time.Sleep(time.Second * time.Duration(secondsToRun))
 	close(done)
 }
+
+func main() {
+	args := os.Args[1:]
+	var percentageLoad, secondsToRun = readArguments(args)
+	var percentage = calcuatePercentage(percentageLoad)
+	var cpuCount = calcuateCPUCount(percentage, runtime.NumCPU())
+	outputLoadAndCount(cpuCount, percentage, percentageLoad)
+	troll(cpuCount, secondsToRun)
+}

main_test.go

@@ -0,0 +1,46 @@
+package main
+
+import "testing"
+
+func TestReadArguments(t *testing.T) {
+	t.Run("verify with correct parameters", func(t *testing.T) {
+		want := int64(12)
+		args := []string{"12", "12"}
+		var load, percentage = readArguments(args)
+		if load != want || percentage != want {
+			t.Errorf("should have recieved a value back")
+		}
+	})
+
+	t.Run("verify with incorrect parameters", func(t *testing.T) {
+		args := []string{"not-a-number", "not-a-number"}
+		var load, percentage = readArguments(args)
+		if load != 0 && percentage != 0 {
+			t.Errorf("should have recieved zero")
+		}
+	})
+}
+
+func TestCaluatePercentage(t *testing.T) {
+	t.Run("calculates the percentage based on input", func(t *testing.T) {
+		percentageLoad := int64(78)
+		want := float64(0.78)
+		var percentage = calcuatePercentage(percentageLoad)
+		if want != percentage {
+			t.Errorf("should have recieved a value back")
+		}
+	})
+}
+
+func TestCalculateCPUCount(t *testing.T) {
+	t.Run("calculates the percentage based on input", func(t *testing.T) {
+		percentageLoad := float64(0.78)
+		CPU := 4
+		want := float64(3.12)
+		var percentage = calcuateCPUCount(percentageLoad, CPU)
+		print(percentage)
+		if want != percentage {
+			t.Errorf("should have recieved a value back")
+		}
+	})
+}