folly/wangle/test/FSM.cpp

   1 /*
   2  * Copyright 2014 Facebook, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *   http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <gtest/gtest.h>
  18 #include <folly/wangle/detail/FSM.h>
  19
  20 using namespace folly::wangle::detail;
  21
  22 enum class State { A, B };
  23
  24 TEST(FSM, ctor) {
  25   FSM<State> fsm(State::A);
  26   EXPECT_EQ(State::A, fsm.getState());
  27 }
  28
  29 TEST(FSM, update) {
  30   FSM<State> fsm(State::A);
  31   EXPECT_TRUE(fsm.updateState(State::A, State::B, []{}));
  32   EXPECT_EQ(State::B, fsm.getState());
  33 }
  34
  35 TEST(FSM, badUpdate) {
  36   FSM<State> fsm(State::A);
  37   EXPECT_FALSE(fsm.updateState(State::B, State::A, []{}));
  38 }
  39
  40 TEST(FSM, actionOnUpdate) {
  41   FSM<State> fsm(State::A);
  42   size_t count = 0;
  43   fsm.updateState(State::A, State::B, [&]{ count++; });
  44   EXPECT_EQ(1, count);
  45 }
  46
  47 TEST(FSM, noActionOnBadUpdate) {
  48   FSM<State> fsm(State::A);
  49   size_t count = 0;
  50   fsm.updateState(State::B, State::A, [&]{ count++; });
  51   EXPECT_EQ(0, count);
  52 }
  53
  54 TEST(FSM, magicMacros) {
  55   struct MyFSM : public FSM<State> {
  56     size_t count = 0;
  57     MyFSM() : FSM<State>(State::A) {}
  58     void twiddle() {
  59       FSM_START
  60         FSM_UPDATE(State::A, State::B, [&]{ count++; });
  61         FSM_UPDATE(State::B, State::A, [&]{ count--; });
  62       FSM_END
  63     }
  64   };
  65
  66   MyFSM fsm;
  67
  68   fsm.twiddle();
  69   EXPECT_EQ(State::B, fsm.getState());
  70   EXPECT_EQ(1, fsm.count);
  71
  72   fsm.twiddle();
  73   EXPECT_EQ(State::A, fsm.getState());
  74   EXPECT_EQ(0, fsm.count);
  75 }
  76
  77 TEST(FSM, magicMacros2) {
  78   struct MyFSM : public FSM<State> {
  79     size_t count = 0;
  80     size_t count2 = 0;
  81     MyFSM() : FSM<State>(State::A) {}
  82     void twiddle() {
  83       FSM_START
  84         FSM_UPDATE2(State::A, State::B, [&]{ count++; }, count2++);
  85         FSM_UPDATE2(State::B, State::A, [&]{ count--; }, count2--);
  86       FSM_END
  87     }
  88   };
  89
  90   MyFSM fsm;
  91
  92   fsm.twiddle();
  93   EXPECT_EQ(State::B, fsm.getState());
  94   EXPECT_EQ(1, fsm.count);
  95   EXPECT_EQ(1, fsm.count2);
  96
  97   fsm.twiddle();
  98   EXPECT_EQ(State::A, fsm.getState());
  99   EXPECT_EQ(0, fsm.count);
 100   EXPECT_EQ(0, fsm.count2);
 101 }