Add pkg_editor unit tests with random files of varying sizes

This commit adds randomness to the pkg_editor unit tests that deal with packing and unpacking files. This ensures that we can cover all file sizes and all types of file contents and improves the robustness of our pkg_editor code.

Author: IlanTruanovsky

lib/pkg_editor/test/CMakeLists.txt

@@ -3,6 +3,12 @@
 
 add_executable(pkg_editor_test pkg_editor_test.cpp)
 target_link_libraries(pkg_editor_test PRIVATE CppUTest pkg_editor)
+
+# This section can be removed once the minimum required version of GCC has been raised to 9
+if(NOT CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+       target_link_libraries(pkg_editor_test PRIVATE stdc++fs)
+endif()
+
 add_test(pkg_editor_test pkg_editor_test -v)
 
 if(ZLIB_FOUND)

lib/pkg_editor/test/pkg_editor_test.cpp

@@ -12,9 +12,17 @@
 #pragma warning(pop)
 #endif
 
+// Replace this library with <filesystem> once we move to GCC 8 or newer
+// versions
+#define _SILENCE_EXPERIMENTAL_FILESYSTEM_DEPRECATION_WARNING 1
+#include <experimental/filesystem>
+
+#include <climits>
+#include <random>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <string>
 
 #include "pkg_editor/pkg_editor.h"
 #include <assert.h>
@@ -40,6 +48,11 @@
 #define PACK_UNPACK_FILE ".pack_unpack"
 #define PACK_UNPACK_DIR ".pack_unpack_dir"
 
+using random_bytes_engine =
+    std::independent_bits_engine<std::default_random_engine, CHAR_BIT,
+                                 unsigned int>;
+namespace fs = std::experimental::filesystem::v1;
+
 static void l_remove_file(const char *filename) {
 #ifdef _WIN32
   _unlink(filename);
@@ -379,7 +392,7 @@ TEST(package, pack) {
   CHECK_EQUAL(1, result);
 }
 
-static bool files_same(const char *f1, const char *f2) {
+static bool files_same(const fs::path f1, const fs::path f2) {
   std::ifstream file1(f1, std::ifstream::ate | std::ifstream::binary);
   std::ifstream file2(f2, std::ifstream::ate | std::ifstream::binary);
   file1.exceptions(std::ifstream::failbit | std::ifstream::badbit);
@@ -398,11 +411,55 @@ static bool files_same(const char *f1, const char *f2) {
   return std::equal(begin1, std::istreambuf_iterator<char>(), begin2);
 }
 
+static void generate_random_file(const fs::path &name, size_t size) {
+  random_bytes_engine rbe;
+  std::ofstream file(name);
+  file.exceptions(std::ifstream::failbit | std::ifstream::badbit);
+  std::generate_n(std::ostreambuf_iterator<char>(file), size,
+                  [&] { return (char)rbe(); });
+}
+
+// Creates a folder consisting of a certain number of files with random contents
+// and random sizes
+static std::vector<fs::path> generate_tmp_folder(const fs::path &tmpdir) {
+  std::vector<fs::path> files;
+
+  std::mt19937 gen{};
+  std::uniform_int_distribution dis{0, 100000};
+
+  fs::remove_all(tmpdir);
+  fs::create_directory(tmpdir);
+
+  // Guarantee we always have one large and one empty file
+  generate_random_file(files.emplace_back(tmpdir / "empty_file"), 0);
+  generate_random_file(files.emplace_back(tmpdir / "large_file"), 10000000);
+
+  const int num_random_files = 8;
+  for (int i = 0; i < num_random_files; i++) {
+    std::string filename = "file" + std::to_string(i);
+    generate_random_file(files.emplace_back(tmpdir / filename), dis(gen));
+  }
+
+  return files;
+}
+
+static bool is_same_tmpdir(const std::vector<fs::path> &files,
+                           const fs::path &unpack_dir) {
+  return std::all_of(files.begin(), files.end(), [&](const fs::path &path) {
+    fs::path unpacked_file_path = unpack_dir / path;
+    return files_same(path, unpacked_file_path);
+  });
+}
+
 TEST(package, unpack) {
   int result;
+  fs::path tmpdir = "tmp";
+  std::string tmpdir_string = tmpdir.string();
+  const char *tmpdir_c_str = tmpdir_string.c_str();
+  std::vector<fs::path> files = generate_tmp_folder(tmpdir);
 
   // Create a known good input.
-  const char *test_input[] = {"include", "src", "test", NULL};
+  const char *test_input[] = {tmpdir_c_str, NULL};
   result = acl_pkg_pack(PACK_UNPACK_FILE, test_input);
   CHECK_EQUAL(1, result);
 
@@ -411,17 +468,17 @@ TEST(package, unpack) {
   CHECK_EQUAL(1, result);
 
   // Compare some files to be sure that they are the same.
-  CHECK_EQUAL(true,
-              files_same("CMakeLists.txt", PACK_UNPACK_DIR "/CMakeLists.txt"));
-  CHECK_EQUAL(true, files_same("test/pkg_editor_test.cpp",
-                               PACK_UNPACK_DIR "/test/pkg_editor_test.cpp"));
+  CHECK(is_same_tmpdir(files, PACK_UNPACK_DIR));
 }
 
 TEST(package, unpack_buffer) {
   int result;
-
+  fs::path tmpdir = "tmp";
+  std::string tmpdir_string = tmpdir.string();
+  const char *tmpdir_c_str = tmpdir_string.c_str();
+  std::vector<fs::path> files = generate_tmp_folder(tmpdir);
   // Create a known good input.
-  const char *test_input[] = {"include", "src", "test", NULL};
+  const char *test_input[] = {"include", "src", "test", tmpdir_c_str, NULL};
   result = acl_pkg_pack(PACK_UNPACK_FILE, test_input);
   CHECK_EQUAL(1, result);
 
@@ -447,13 +504,18 @@ TEST(package, unpack_buffer) {
                                PACK_UNPACK_DIR "/src/pkg_editor.c"));
   CHECK_EQUAL(true, files_same("test/pkg_editor_test.cpp",
                                PACK_UNPACK_DIR "/test/pkg_editor_test.cpp"));
+  CHECK(is_same_tmpdir(files, PACK_UNPACK_DIR));
 }
 
 TEST(package, unpack_buffer_stdin) {
   int result;
+  fs::path tmpdir = "tmp";
+  std::string tmpdir_string = tmpdir.string();
+  const char *tmpdir_c_str = tmpdir_string.c_str();
+  std::vector<fs::path> files = generate_tmp_folder(tmpdir);
 
   // Create a known good input.
-  const char *test_input[] = {"include", "src", "test", NULL};
+  const char *test_input[] = {"include", "src", "test", tmpdir_c_str, NULL};
   result = acl_pkg_pack(PACK_UNPACK_FILE, test_input);
   CHECK_EQUAL(1, result);
 
@@ -496,5 +558,6 @@ TEST(package, unpack_buffer_stdin) {
                                PACK_UNPACK_DIR "/src/pkg_editor.c"));
   CHECK_EQUAL(true, files_same("test/pkg_editor_test.cpp",
                                PACK_UNPACK_DIR "/test/pkg_editor_test.cpp"));
+  CHECK(is_same_tmpdir(files, PACK_UNPACK_DIR));
 }
 #endif