test: add piroutine unit tests

Author: elgopher

piroutine/piroutine_test.go

@@ -6,8 +6,10 @@ package piroutine_test
 import (
 	"testing"
 
+	"github.com/elgopher/pi/piloop"
 	"github.com/elgopher/pi/piroutine"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestPiroutine(t *testing.T) {
@@ -45,3 +47,78 @@ func TestRoutine_Resume(t *testing.T) {
 		assert.False(t, routine.Resume()) // nothing changed
 	})
 }
+
+func TestCall(t *testing.T) {
+	t.Run("should call callback", func(t *testing.T) {
+		var executed = false
+		step := piroutine.Call(func() {
+			executed = true
+		})
+		// when
+		result := step()
+		// then
+		assert.True(t, executed)
+		assert.True(t, result)
+	})
+}
+
+func TestSlowDown(t *testing.T) {
+	t.Run("should wait n updates before running callback", func(t *testing.T) {
+		executionCount := 0
+		step := piroutine.SlowDown(2, func() bool {
+			executionCount++
+			return true
+		})
+		assert.False(t, step())
+		assert.Equal(t, 0, executionCount)
+		assert.False(t, step())
+		assert.Equal(t, 0, executionCount)
+		assert.True(t, step())
+		assert.Equal(t, 1, executionCount)
+	})
+
+	t.Run("should immediately run callback", func(t *testing.T) {
+		executionCount := 0
+		step := piroutine.SlowDown(0, func() bool {
+			executionCount++
+			return true
+		})
+		assert.True(t, step())
+		assert.Equal(t, 1, executionCount)
+	})
+
+	t.Run("should wait another n updates after callback returned false", func(t *testing.T) {
+		executionCount := 0
+		step := piroutine.SlowDown(3, func() bool {
+			executionCount++
+			return executionCount%2 == 0
+		})
+		for range 3 {
+			assert.False(t, step()) // wait
+		}
+		assert.False(t, step()) // callback returns false
+		for range 3 {
+			assert.False(t, step()) // wait
+		}
+		assert.True(t, step()) // callback returns true this time
+		assert.Equal(t, 2, executionCount)
+	})
+}
+
+func TestRoutine_ScheduleOn(t *testing.T) {
+	t.Run("should run callback on event", func(t *testing.T) {
+		executionCount := 0
+		step := func() bool {
+			executionCount++
+			return true
+		}
+		routine := piroutine.New(step)
+		// when
+		handler := routine.ScheduleOn(piloop.EventDraw)
+		// then
+		require.True(t, piloop.Target().IsSubscribed(handler))
+		piloop.Target().Publish(piloop.EventDraw) // runs callback and unsubscribes handlers
+		assert.Equal(t, 1, executionCount)
+		assert.False(t, piloop.Target().IsSubscribed(handler))
+	})
+}