package compiler_test import ( "math/big" "testing" "github.com/stretchr/testify/require" ) func TestDefer(t *testing.T) { t.Run("Simple", func(t *testing.T) { src := `package main var a int func Main() int { return h() + a } func h() int { defer f() return 1 } func f() { a += 2 }` eval(t, src, big.NewInt(3)) }) t.Run("ValueUnchanged", func(t *testing.T) { src := `package main var a int func Main() int { defer f() a = 3 return a } func f() { a += 2 }` eval(t, src, big.NewInt(3)) }) t.Run("Function", func(t *testing.T) { src := `package main var a int func Main() int { return h() + a } func h() int { defer f() a = 3 return g() } func g() int { a++ return a } func f() { a += 2 }` eval(t, src, big.NewInt(10)) }) t.Run("MultipleDefers", func(t *testing.T) { src := `package main var a int func Main() int { return h() + a } func h() int { defer f() defer g() a = 3 return a } func g() { a *= 2 } func f() { a += 2 }` eval(t, src, big.NewInt(11)) }) t.Run("FunctionLiteral", func(t *testing.T) { src := `package main var a int func Main() int { return h() + a } func h() int { defer func() { a = 10 }() a = 3 return a }` eval(t, src, big.NewInt(13)) }) t.Run("NoReturnReturn", func(t *testing.T) { src := `package main var i int func Main() { defer func() { i++ }() return }` vm := vmAndCompile(t, src) err := vm.Run() require.NoError(t, err) require.Equal(t, 0, vm.Estack().Len(), "stack contains unexpected items") }) t.Run("NoReturnNoReturn", func(t *testing.T) { src := `package main var i int func Main() { defer func() { i++ }() }` vm := vmAndCompile(t, src) err := vm.Run() require.NoError(t, err) require.Equal(t, 0, vm.Estack().Len(), "stack contains unexpected items") }) } func TestRecover(t *testing.T) { t.Run("Panic", func(t *testing.T) { src := `package foo var a int func Main() int { return h() + a } func h() int { defer func() { if r := recover(); r != nil { a = 3 } else { a = 4 } }() a = 1 panic("msg") return a }` eval(t, src, big.NewInt(3)) }) t.Run("NoPanic", func(t *testing.T) { src := `package foo var a int func Main() int { return h() + a } func h() int { defer func() { if r := recover(); r != nil { a = 3 } else { a = 4 } }() a = 1 return a }` eval(t, src, big.NewInt(5)) }) t.Run("PanicInDefer", func(t *testing.T) { src := `package foo var a int func Main() int { return h() + a } func h() int { defer func() { a += 2; recover() }() defer func() { a *= 3; recover(); panic("again") }() a = 1 panic("msg") return a }` eval(t, src, big.NewInt(5)) }) } func TestDeferNoGlobals(t *testing.T) { src := `package foo func Main() int { a := 1 defer func() { recover() }() panic("msg") return a }` eval(t, src, big.NewInt(0)) }