tiny fix

examples/fibonacci_test.go

@@ -27,7 +27,7 @@ func Test_fibonacci(t *testing.T) {
 		{in: 10, exp: 55},
 		{in: 5, exp: 5},
 	} {
-		ret, retTypes, err := vm.ExecExportedFunction("fib", uint64(c.in))
+		ret, retTypes, err := vm.ExecExportedFunction("fibonacci", uint64(c.in))
 		require.NoError(t, err)
 		require.Len(t, ret, len(retTypes))
 		require.Equal(t, wasm.ValueTypeI32, retTypes[0])

examples/wasm/fibonacci.go

@@ -3,10 +3,10 @@ package main
 
 func main() {}
 
-//export fib
-func fib(in uint32) uint32 {
+//export fibonacci
+func fibonacci(in uint32) uint32 {
 	if in <= 1 {
 		return in
 	}
-	return fib(in-1) + fib(in-2)
+	return fibonacci(in-1) + fibonacci(in-2)
 }

wasm/vm_memory.go

@@ -141,6 +141,7 @@ func memoryGrow(vm *VirtualMachine) {
 		uint64(n+uint32(len(vm.Memory)/vmPageSize)) > uint64(*(vm.InnerModule.SecMemory[0].Max)) {
 		v := int32(-1)
 		vm.OperandStack.Push(uint64(v))
+		return
 	}
 
 	vm.OperandStack.Push(uint64(len(vm.Memory)) / vmPageSize)

wasm/vm_memory_test.go

@@ -404,17 +404,36 @@ func Test_memorySize(t *testing.T) {
 }
 
 func Test_memoryGrow(t *testing.T) {
-	vm := &VirtualMachine{
-		ActiveContext: &NativeFunctionContext{},
-		Memory:        make([]byte, vmPageSize*2),
-		OperandStack:  NewVirtualMachineOperandStack(),
-		InnerModule: &Module{
-			SecMemory: []*MemoryType{{}},
-		},
-	}
+	t.Run("ok", func(t *testing.T) {
+		vm := &VirtualMachine{
+			ActiveContext: &NativeFunctionContext{},
+			Memory:        make([]byte, vmPageSize*2),
+			OperandStack:  NewVirtualMachineOperandStack(),
+			InnerModule: &Module{
+				SecMemory: []*MemoryType{{}},
+			},
+		}
+
+		vm.OperandStack.Push(5)
+		memoryGrow(vm)
+		assert.Equal(t, uint64(0x2), vm.OperandStack.Pop())
+		assert.Equal(t, 7, len(vm.Memory)/vmPageSize)
+	})
+
+	t.Run("oom", func(t *testing.T) {
+		vm := &VirtualMachine{
+			ActiveContext: &NativeFunctionContext{},
+			Memory:        make([]byte, vmPageSize*2),
+			OperandStack:  NewVirtualMachineOperandStack(),
+			InnerModule: &Module{
+				SecMemory: []*MemoryType{{Max: uint32Ptr(0)}},
+			},
+		}
+
+		exp := int32(-1)
+		vm.OperandStack.Push(5)
+		memoryGrow(vm)
+		assert.Equal(t, uint64(exp), vm.OperandStack.Pop())
+	})
 
-	vm.OperandStack.Push(5)
-	memoryGrow(vm)
-	assert.Equal(t, uint64(0x2), vm.OperandStack.Pop())
-	assert.Equal(t, 7, len(vm.Memory)/vmPageSize)
 }