Improve BufferedWriterTest to use parametrized tests and do the same …

…random logic from D35053135 (#140)

Summary:
Pull Request resolved: #140

See diff summary of previous diff, this does the same thing where we iterate over many chunk sizes

Plus, see D35053135 (3eb2484) where we fixed flaky tests. we do the same here

Reviewed By: elliottlawrence

Differential Revision: D35058622

fbshipit-source-id: f61abee097ee6ac63a1469ff0af64d78e47794be

fbpcf/io/api/test/BufferedWriterTest.cpp

@@ -8,6 +8,7 @@
 #include <gtest/gtest.h>
 #include <stdio.h>
 #include <filesystem>
+#include <random>
 #include <string>
 #include "folly/logging/xlog.h"
 
@@ -17,12 +18,16 @@
 
 namespace fbpcf::io {
 
-TEST(BufferedWriterTest, testWritingToFile) {
-  std::string base_dir = IOTestHelper::getBaseDirFromPath(__FILE__);
-  std::string file_to_write_to =
-      base_dir + "data/buffered_writer_writer_test_file.txt";
-  auto writer = fbpcf::io::LocalFileWriter(file_to_write_to);
-  auto bufferedWriter = std::make_unique<BufferedWriter>(writer, 40);
+inline void runBufferedWriterTest(size_t chunkSize) {
+  std::string baseDir = IOTestHelper::getBaseDirFromPath(__FILE__);
+  std::random_device rd;
+  std::default_random_engine defEngine(rd());
+  std::uniform_int_distribution<int> intDistro(1, 25000);
+  auto randint = intDistro(defEngine);
+  std::string fileToWriteTo = baseDir + "data/local_file_writer_test_file" +
+      std::to_string(randint) + ".txt";
+  auto writer = fbpcf::io::LocalFileWriter(fileToWriteTo);
+  auto bufferedWriter = std::make_unique<BufferedWriter>(writer, chunkSize);
 
   std::string to_write = "this file tests the buffered writer\n";
   auto buf =
@@ -61,10 +66,34 @@ TEST(BufferedWriterTest, testWritingToFile) {
     Verify that file contents match the expected
   */
   IOTestHelper::expectFileContentsMatch(
-      file_to_write_to,
-      base_dir + "data/expected_buffered_writer_test_file.txt");
+      fileToWriteTo, baseDir + "data/expected_buffered_writer_test_file.txt");
 
-  IOTestHelper::cleanup(file_to_write_to);
+  IOTestHelper::cleanup(fileToWriteTo);
 }
 
+class BufferedWriterTest
+    : public ::testing::TestWithParam<size_t> { // the only parameter is the
+                                                // chunk size
+ protected:
+  void SetUp() override {}
+
+  void TearDown() override {}
+};
+
+TEST_P(BufferedWriterTest, testWritingToFile) {
+  auto chunkSize = GetParam();
+
+  runBufferedWriterTest(chunkSize);
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    BufferedWriterTest,
+    BufferedWriterTest,
+    ::testing::Values(1, 10, 40, 100, 200, 500, 1000, 4096),
+    [](const testing::TestParamInfo<BufferedWriterTest::ParamType>& info) {
+      auto chunkSize = std::to_string(info.param);
+      std::string name = "Chunk_size_" + chunkSize;
+      return name;
+    });
+
 } // namespace fbpcf::io