test: add unit tests for p1/p2

internal/2018/DayThree/code_test.go

@@ -0,0 +1,25 @@
+package daythree
+
+import "testing"
+
+var testInput = []string{
+	"#1 @ 1,3: 4x4",
+	"#2 @ 3,1: 4x4",
+	"#3 @ 5,5: 2x2",
+}
+
+func TestPartOne(t *testing.T) {
+	expected := 4
+	got := PartOne(testInput)
+	if got != expected {
+		t.Errorf("PartOne() = %d, want %d", got, expected)
+	}
+}
+
+func TestPartTwo(t *testing.T) {
+	expected := 3
+	got := PartTwo(testInput)
+	if got != expected {
+		t.Errorf("PartTwo() = %d, want %d", got, expected)
+	}
+}