diff --git a/ph7_test.go b/ph7_test.go
index 3383dcf..48ca19d 100644
--- a/ph7_test.go
+++ b/ph7_test.go
@@ -31,6 +31,33 @@ func mustSucceedF(t *testing.T, f func() error) {
 	}
 }
 
+func setupVM(t *testing.T, script string) (vm *ph7.VM, close func()) {
+	t.Helper()
+	engine, err := ph7.NewEngine()
+	mustSucceed(t, err)
+
+	vm, err = engine.Compile([]byte(script), true)
+	if err != nil {
+		mustSucceed(t, engine.Close())
+		mustSucceed(t, err)
+	}
+
+	return vm, func() {
+		mustSucceed(t, vm.Close())
+		mustSucceed(t, engine.Close())
+	}
+}
+
+func expectOutput(t *testing.T, vm *ph7.VM, expected string) {
+	t.Helper()
+	mustSucceed(t, vm.Exec())
+	output, err := vm.ExtractOutput()
+	mustSucceed(t, err)
+	if output != expected {
+		t.Fatalf("expected %q, got %q", expected, output)
+	}
+}
+
 func TestCore(t *testing.T) {
 	engine, err := ph7.NewEngine()
 	mustSucceed(t, err)
@@ -72,27 +99,21 @@ func TestCompileError(t *testing.T) {
 }
 
 func TestOutputWriter(t *testing.T) {
-	const source = `<?php
+	const source = `
 		for ($x = 0; $x <= 1000; $x++) {
 			echo $x;
-		}
-		?>`
+		}`
 	var expected bytes.Buffer
 	for i := 0; i <= 1000; i++ {
 		_, err := fmt.Fprint(&expected, i)
 		mustSucceed(t, err)
 	}
 
-	engine, err := ph7.NewEngine()
-	mustSucceed(t, err)
-	defer mustSucceedF(t, engine.Close)
-
-	vm, err := engine.Compile([]byte(source), false)
-	mustSucceed(t, err)
-	defer vm.Close()
+	vm, close := setupVM(t, source)
+	defer close()
 
 	var actual bytes.Buffer
-	err = vm.SetOutputWriter(&actual)
+	err := vm.SetOutputWriter(&actual)
 	mustSucceed(t, err)
 
 	mustSucceed(t, vm.Exec())
@@ -104,3 +125,63 @@ func TestOutputWriter(t *testing.T) {
 
 // TODO Test failing writer, including vm.OutputWriteError
 // TODO Test setting writer twice
+
+type CtxFunc func(*ph7.Context) error
+
+func (r CtxFunc) Call(ctx *ph7.Context, _ []*ph7.Value) ph7.ResultCode {
+	err := r(ctx)
+	if err != nil {
+		return r(ctx).(ph7.Error).Code
+	}
+	return ph7.ResultCodeOK
+}
+
+func testResultCode(t *testing.T, expectedOutput string, f CtxFunc) {
+	t.Helper()
+	const script = "echo doStuff();"
+	vm, close := setupVM(t, script)
+	defer close()
+
+	mustSucceed(t, vm.CreateFunction("doStuff", f))
+	expectOutput(t, vm, expectedOutput)
+}
+
+func TestContextResultInt(t *testing.T) {
+	testResultCode(t, "42", func(ctx *ph7.Context) error {
+		return ctx.ResultInt(42)
+	})
+}
+
+func TestContextResultInt64(t *testing.T) {
+	testResultCode(t, "1234", func(ctx *ph7.Context) error {
+		return ctx.ResultInt64(1234)
+	})
+}
+
+func TestContextResultBool(t *testing.T) {
+	testResultCode(t, "TRUE", func(ctx *ph7.Context) error {
+		return ctx.ResultBool(true)
+	})
+	testResultCode(t, "", func(ctx *ph7.Context) error {
+		return ctx.ResultBool(false)
+	})
+}
+
+func TestContextResultDouble(t *testing.T) {
+	testResultCode(t, "1.23", func(ctx *ph7.Context) error {
+		return ctx.ResultDouble(1.23)
+	})
+}
+
+func TestContextResultNull(t *testing.T) {
+	testResultCode(t, "", (*ph7.Context).ResultNull)
+}
+
+func TestContextResultString(t *testing.T) {
+	testResultCode(t, "hello", func(ctx *ph7.Context) error {
+		return ctx.ResultString("hello")
+	})
+}
+
+// TODO TestContextResultValue
+// TODO TestContextResultResource