base/state_transitions_unittest.cc

   1 // Copyright 2020 The Chromium Authors
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/state_transitions.h"
   6
   7 #include <ostream>
   8 #include <string>
   9
  10 #include "base/test/gtest_util.h"
  11 #include "build/build_config.h"
  12 #include "testing/gmock/include/gmock/gmock.h"
  13 #include "testing/gtest/include/gtest/gtest.h"
  14
  15 namespace base {
  16
  17 enum class State { kState1 = 0, kState2, kState3, kState4 };
  18
  19 std::ostream& operator<<(std::ostream& o, const State& s) {
  20   return o << static_cast<int>(s);
  21 }
  22
  23 TEST(StateTransitionsTest, Constructor) {
  24   // No expectations, just make sure the constructor works.
  25   const StateTransitions<State> transitions({
  26       {State::kState1, {State::kState2, State::kState3}},
  27       {State::kState2, {State::kState3, State::kState4}},
  28   });
  29 }
  30
  31 TEST(StateTransitionsTest, GetValidTransitions) {
  32   const StateTransitions<State> transitions({
  33       {State::kState1, {State::kState2, State::kState3}},
  34       {State::kState2, {State::kState3, State::kState4}},
  35   });
  36   EXPECT_THAT(transitions.GetValidTransitions(State::kState1),
  37               testing::ElementsAre(State::kState2, State::kState3));
  38   EXPECT_THAT(transitions.GetValidTransitions(State::kState2),
  39               testing::ElementsAre(State::kState3, State::kState4));
  40   EXPECT_THAT(transitions.GetValidTransitions(State::kState3),
  41               testing::ElementsAre());
  42   EXPECT_THAT(transitions.GetValidTransitions(State::kState4),
  43               testing::ElementsAre());
  44 }
  45
  46 TEST(StateTransitionsTest, IsTransitionValid) {
  47   const StateTransitions<State> transitions({
  48       {State::kState1, {State::kState2, State::kState3}},
  49       {State::kState2, {State::kState3, State::kState4}},
  50   });
  51   ASSERT_TRUE(transitions.IsTransitionValid(State::kState1, State::kState2));
  52   ASSERT_TRUE(transitions.IsTransitionValid(State::kState2, State::kState3));
  53   ASSERT_FALSE(transitions.IsTransitionValid(State::kState1, State::kState4));
  54   // kState3 was omitted from the definition.
  55   ASSERT_FALSE(transitions.IsTransitionValid(State::kState3, State::kState4));
  56 }
  57
  58 TEST(StateTransitionsTest, DCHECK_STATE_TRANSITION) {
  59   const StateTransitions<State> transitions({
  60       {State::kState1, {State::kState2, State::kState3}},
  61       {State::kState2, {State::kState3, State::kState4}},
  62   });
  63   DCHECK_STATE_TRANSITION(&transitions, State::kState1, State::kState2);
  64   DCHECK_STATE_TRANSITION(&transitions, State::kState2, State::kState3);
  65
  66 #if DCHECK_IS_ON()
  67   // EXPECT_DEATH is not defined on IOS.
  68 #if !BUILDFLAG(IS_IOS)
  69   EXPECT_DEATH(
  70       DCHECK_STATE_TRANSITION(&transitions, State::kState1, State::kState4),
  71       "Check failed.*Invalid transition: 0 -> 3");
  72   // kState3 was omitted from the definition.
  73   EXPECT_DEATH(
  74       DCHECK_STATE_TRANSITION(&transitions, State::kState3, State::kState4),
  75       "Check failed.*Invalid transition: 2 -> 3");
  76 #endif  // !BUILDFLAG(IS_IOS)
  77 #endif  // DCHECK_IS_ON()
  78 }
  79
  80 // Test that everything works OK with some other data type.
  81 TEST(StateTransitionsTest, NonEnum) {
  82   const StateTransitions<std::string> transitions({
  83       {"state1", {"state2", "state3"}},
  84       {"state2", {"state3", "state4"}},
  85   });
  86   ASSERT_TRUE(transitions.IsTransitionValid("state1", "state2"));
  87   ASSERT_TRUE(transitions.IsTransitionValid("state2", "state3"));
  88   ASSERT_FALSE(transitions.IsTransitionValid("state1", "state4"));
  89   // kState3 was omitted from the definition.
  90   ASSERT_FALSE(transitions.IsTransitionValid("state3", "state4"));
  91   DCHECK_STATE_TRANSITION(&transitions, "state1", "state2");
  92   DCHECK_STATE_TRANSITION(&transitions, "state2", "state3");
  93
  94   // Try some states that are not in the specification at all.
  95   ASSERT_FALSE(transitions.IsTransitionValid("foo", "state2"));
  96   ASSERT_FALSE(transitions.IsTransitionValid("state1", "foo"));
  97   ASSERT_FALSE(transitions.IsTransitionValid("foo", "bar"));
  98 }
  99
 100 }  // namespace base