From a89c95cc580807267909e148e37c61b1abcf644c Mon Sep 17 00:00:00 2001
From: Eric Paniagua <epaniagua@google.com>
Date: Fri, 4 Sep 2020 19:03:12 -0700
Subject: [PATCH] Make RunCycle return std::unique_ptr<State>.

Signed-off-by: Eric Paniagua <epaniagua@google.com>
---
 testing/common/State.cpp                     | 14 ++++++++++++--
 testing/common/State.h                       | 10 ++++++++--
 testing/common/VirtualDeviceTest.cpp         | 18 ++++++------------
 testing/common/VirtualDeviceTest.h           |  8 ++++----
 testing/kaleidoscope/test/simulator_test.cpp | 16 ++++++++++------
 5 files changed, 40 insertions(+), 26 deletions(-)

diff --git a/testing/common/State.cpp b/testing/common/State.cpp
index f4cbe69d..4f0cca39 100644
--- a/testing/common/State.cpp
+++ b/testing/common/State.cpp
@@ -32,8 +32,13 @@ State::State() {
       });
 }
 
-void State::Clear() {
-  keyboard_reports_.clear();
+State::~State() {
+  HIDReportObserver::resetHook(&State::DefaultProcessHidReport);
+}
+
+// static
+void State::DefaultProcessHidReport(uint8_t, const void*, int, int) {
+  // TODO: Log that the report was dropped.
 }
 
 void State::ProcessHidReport(
@@ -79,5 +84,10 @@ void State::ProcessKeyboardReport(const KeyboardReport& report) {
   keyboard_reports_.push_back(report);
 }
 
+void State::Snapshot() {
+  // TODO: Grab a copy of current instantaneous state, like:
+  //  key states, layer stack, led states
+}
+
 }  // namespace testing
 }  // namespace kaleidoscope
diff --git a/testing/common/State.h b/testing/common/State.h
index 2581f044..18eb9203 100644
--- a/testing/common/State.h
+++ b/testing/common/State.h
@@ -29,9 +29,9 @@ namespace testing {
 
 class State {
  public:
-  State();
+  ~State();
 
-  void Clear();
+  static void DefaultProcessHidReport(uint8_t, const void*, int, int);
 
   void ProcessHidReport(uint8_t id, const void* data, int len, int result);
 
@@ -39,8 +39,14 @@ class State {
   const KeyboardReport& KeyboardReports(size_t i) const;
 
  private:
+  friend class VirtualDeviceTest;
+
+  State();
+
   void ProcessKeyboardReport(const KeyboardReport& report);
 
+  void Snapshot();
+
   std::vector<KeyboardReport> keyboard_reports_;
 };
 
diff --git a/testing/common/VirtualDeviceTest.cpp b/testing/common/VirtualDeviceTest.cpp
index 267ebf7d..5fe82afc 100644
--- a/testing/common/VirtualDeviceTest.cpp
+++ b/testing/common/VirtualDeviceTest.cpp
@@ -16,22 +16,16 @@
 
 #include "testing/common/VirtualDeviceTest.h"
 
+#include <memory>
+
 namespace kaleidoscope {
 namespace testing {
 
-void VirtualDeviceTest::RunCycle() {
-  state_.Clear();
+std::unique_ptr<State> VirtualDeviceTest::RunCycle() {
+  auto state = std::unique_ptr<State>(new State());
   sim_.RunCycle();
-}
-
-void VirtualDeviceTest::RunCycles(size_t n) {
-  if (n == 0) return;
-  state_.Clear();
-  sim_.RunCycles(n);
-}
-
-const State& VirtualDeviceTest::Result() const {
-  return state_;
+  state->Snapshot();
+  return state;
 }
 
 }  // namespace testing
diff --git a/testing/common/VirtualDeviceTest.h b/testing/common/VirtualDeviceTest.h
index 6c15eace..747e00c5 100644
--- a/testing/common/VirtualDeviceTest.h
+++ b/testing/common/VirtualDeviceTest.h
@@ -31,11 +31,11 @@ namespace testing {
 
 class VirtualDeviceTest : public ::testing::Test {
  protected:
-  void RunCycle();
-  void RunCycles(size_t n);
-
-  const State& Result() const;
+  std::unique_ptr<State> RunCycle();
 
+  // DO NOT REMOVE: This namespace qualification is required. Otherwise the
+  // linker decides this symbol is really ::kaleidoscope::simulator::Simulator.
+  // No idea why.
   ::kaleidoscope::testing::Simulator sim_;
 
  private:
diff --git a/testing/kaleidoscope/test/simulator_test.cpp b/testing/kaleidoscope/test/simulator_test.cpp
index ad7775e8..f8f13171 100644
--- a/testing/kaleidoscope/test/simulator_test.cpp
+++ b/testing/kaleidoscope/test/simulator_test.cpp
@@ -39,20 +39,24 @@ class KeyboardReports : public VirtualDeviceTest {};
 
 TEST_F(KeyboardReports, KeysActiveWhenPressed) {
   sim_.Press(2, 1); // A
-  RunCycle();
+  auto state = RunCycle();
 
-  EXPECT_EQ(Result().KeyboardReports().size(), 1);
+  ASSERT_EQ(state->KeyboardReports().size(), 1);
   EXPECT_THAT(
-      Result().KeyboardReports(0).ActiveKeycodes(),
+      state->KeyboardReports(0).ActiveKeycodes(),
       ContainsKey(Key_A));
 
   sim_.Release(2, 1);  // A
-  RunCycles(2);
+  state = RunCycle();
 
-  EXPECT_EQ(Result().KeyboardReports().size(), 1);
+  ASSERT_EQ(state->KeyboardReports().size(), 1);
   EXPECT_THAT(
-      Result().KeyboardReports(0).ActiveKeycodes(),
+      state->KeyboardReports(0).ActiveKeycodes(),
       IsEmpty());
+
+  state = RunCycle();  // 2 cycles later
+
+  EXPECT_EQ(state->KeyboardReports().size(), 0);
 }
 
 }  // namespace