Add unit-tests for AutoPopStack.

issues #289

PiperOrigin-RevId: 310247369

common/util/BUILD

@@ -17,7 +17,8 @@ cc_library(
     name = "auto_pop_stack",
     hdrs = ["auto_pop_stack.h"],
     deps = [
-        "//common/util:iterator_adaptors",
+        ":iterator_adaptors",
+        ":logging",
     ],
 )
 
@@ -244,6 +245,16 @@ cc_test(
     ],
 )
 
+cc_test(
+    name = "auto_pop_stack_test",
+    srcs = ["auto_pop_stack_test.cc"],
+    deps = [
+        ":auto_pop_stack",
+        ":iterator_range",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
 cc_test(
     name = "file_util_test",
     srcs = ["file_util_test.cc"],

common/util/auto_pop_stack.h

@@ -21,6 +21,7 @@
 #include <vector>
 
 #include "common/util/iterator_adaptors.h"
+#include "common/util/logging.h"
 
 namespace verible {
 

common/util/auto_pop_stack_test.cc

@@ -0,0 +1,68 @@
+// Copyright 2017-2020 The Verible Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "common/util/auto_pop_stack.h"
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "common/util/iterator_range.h"
+
+namespace verible {
+namespace {
+
+using ::testing::ElementsAre;
+
+typedef AutoPopStack<int> IntStack;
+
+// Test that AutoPop properly pushes and pops nodes on and off the stack
+TEST(AutoPopStackTest, PushPopTest) {
+  IntStack context;
+  const auto& const_context = context;
+  EXPECT_TRUE(context.empty());
+  {
+    IntStack::AutoPop p1(&context, 1);
+    EXPECT_EQ(const_context.top(), 1);
+  }
+  EXPECT_TRUE(context.empty());
+  IntStack::AutoPop p2(&context, 2);
+  {
+    IntStack::AutoPop p3(&context, 3);
+    EXPECT_EQ(const_context.top(), 3);
+    IntStack::AutoPop p4(&context, 4);
+    EXPECT_EQ(const_context.top(), 4);
+  }
+  EXPECT_EQ(const_context.top(), 2);
+}
+
+// Test that forward/reverse iterators correctly look down/up the stack.
+TEST(IntStackTest, IteratorsTest) {
+  IntStack context;
+  {
+    IntStack::AutoPop p1(&context, 1);
+    {
+      IntStack::AutoPop p2(&context, 2);
+      {
+        IntStack::AutoPop p3(&context, 3);
+
+        EXPECT_THAT(verible::make_range(context.begin(), context.end()),
+                    ElementsAre(1, 2, 3));
+        EXPECT_THAT(verible::make_range(context.rbegin(), context.rend()),
+                    ElementsAre(3, 2, 1));
+      }
+    }
+  }
+}
+
+}  // namespace
+}  // namespace verible