Began implementing the Instruction Pointer

pkg/pointer/pointer_test.go

@@ -0,0 +1,41 @@
+package pointer
+
+import (
+	"os"
+	"testing"
+
+	"git.adyxax.org/adyxax/gofunge/pkg/field"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewPointer(t *testing.T) {
+	require.Equal(t, NewPointer(), &Pointer{delta: &Delta{1, 0}})
+}
+
+func TestForkPointer(t *testing.T) {
+	file, err := os.Open("../field/test_data/hello.b98")
+	require.NoError(t, err, "Failed to open file")
+	defer file.Close()
+	f, err := field.Load(file)
+	require.NoError(t, err)
+	p := NewPointer()
+	p2 := p.ForkPointer()
+	// We check that p2 is a real copy
+	p.Step(*f)
+	p2.Step(*f)
+	require.Equal(t, p, &Pointer{x: 1, y: 0, delta: &Delta{1, 0}})
+	require.Equal(t, p2, &Pointer{x: 1, y: 0, delta: &Delta{1, 0}})
+}
+
+func TestStep(t *testing.T) { // Step is thoroughly tested in the field package
+	defaultPointer := NewPointer()
+	// File of one char
+	file, err := os.Open("../field/test_data/minimal.b98")
+	require.NoError(t, err, "Failed to open file")
+	defer file.Close()
+	f, err := field.Load(file)
+	require.NoError(t, err)
+	p := NewPointer()
+	p.Step(*f)
+	require.Equal(t, defaultPointer, p)
+}