Eliminate a bunch of allocations

1 files changed, 45 insertions, 0 deletions

diff --git a/state_test.go b/state_test.go
new file mode 100644
index 0000000..fe04a58
--- /dev/null
+++ b/state_test.go
@@ -0,0 +1,45 @@
+package parsec
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestState_Advance(t *testing.T) {
+	ps := InputString("fooo")
+	require.Equal(t, 0, ps.Pos)
+	ps.Advance(2)
+	require.Equal(t, 2, ps.Pos)
+	ps.Advance(1)
+	require.Equal(t, 3, ps.Pos)
+}
+
+func TestState_Get(t *testing.T) {
+	ps := InputString("fooo")
+	require.Equal(t, "fooo", ps.Get())
+	ps.Advance(1)
+	require.Equal(t, "ooo", ps.Get())
+	ps.Advance(4)
+	require.Equal(t, "", ps.Get())
+	ps.Advance(10)
+	require.Equal(t, "", ps.Get())
+}
+
+func TestState_Errors(t *testing.T) {
+	ps := InputString("fooo")
+
+	ps.ErrorHere("hello")
+	require.Equal(t, "offset 0: Expected hello", ps.Error.Error())
+	require.Equal(t, 0, ps.Error.Pos())
+	require.True(t, ps.Errored())
+
+	ps.ClearError()
+	require.False(t, ps.Errored())
+
+	ps.Advance(2)
+	ps.ErrorHere("hello2")
+	require.Equal(t, "offset 2: Expected hello2", ps.Error.Error())
+	require.Equal(t, 2, ps.Error.Pos())
+	require.True(t, ps.Errored())
+}