Defined a testing::SrcDir() function that returns the name of a directory

where ancillary data files can be found.

PiperOrigin-RevId: 487896836
Change-Id: Ie6b1ba734e900fa33872b63090879ee6efe33411

googletest/test/gtest_dirs_test.cc

@@ -0,0 +1,97 @@
+#include <sys/stat.h>
+
+#include <cstdlib>
+#include <cstring>
+#include <string>
+
+#include "gtest/gtest.h"
+#include "gtest/internal/gtest-port.h"
+
+namespace {
+
+class SetEnv {
+ public:
+  // Sets the environment value with name `name` to `value`, unless `value` is
+  // nullptr, in which case it unsets it. Restores the original value on
+  // destruction.
+  SetEnv(const char* name, const char* value) : name_(name) {
+    const char* old_value = getenv(name);
+    if (old_value != nullptr) {
+      saved_value_ = old_value;
+      have_saved_value_ = true;
+    }
+    if (value == nullptr) {
+      GTEST_CHECK_POSIX_SUCCESS_(unsetenv(name));
+    } else {
+      GTEST_CHECK_POSIX_SUCCESS_(setenv(name, value, 1 /*overwrite*/));
+    }
+  }
+
+  ~SetEnv() {
+    if (have_saved_value_) {
+      GTEST_CHECK_POSIX_SUCCESS_(
+          setenv(name_.c_str(), saved_value_.c_str(), 1 /*overwrite*/));
+    } else {
+      GTEST_CHECK_POSIX_SUCCESS_(unsetenv(name_.c_str()));
+    }
+  }
+
+ private:
+  std::string name_;
+  bool have_saved_value_ = false;
+  std::string saved_value_;
+};
+
+class MakeTempDir {
+ public:
+  // Creates a directory with a unique name including `testname`.
+  // The destructor removes it.
+  explicit MakeTempDir(const std::string& testname) {
+    // mkdtemp requires that the last 6 characters of the input pattern
+    // are Xs, and the string is modified by replacing those characters.
+    std::string pattern = "/tmp/" + testname + "_XXXXXX";
+    GTEST_CHECK_(mkdtemp(pattern.data()) != nullptr);
+    dirname_ = pattern;
+  }
+
+  ~MakeTempDir() { GTEST_CHECK_POSIX_SUCCESS_(rmdir(dirname_.c_str())); }
+
+  const char* DirName() const { return dirname_.c_str(); }
+
+ private:
+  std::string dirname_;
+};
+
+bool StartsWith(const std::string& str, const std::string& prefix) {
+  return str.substr(0, prefix.size()) == prefix;
+}
+
+TEST(TempDirTest, InEnvironment) {
+  // Since the test infrastructure might be verifying directory existence or
+  // even creating subdirectories, we need to be careful that the directories we
+  // specify are actually valid.
+  MakeTempDir temp_dir("TempDirTest_InEnvironment");
+  SetEnv set_env("TEST_TMPDIR", temp_dir.DirName());
+  EXPECT_TRUE(StartsWith(testing::TempDir(), temp_dir.DirName()));
+}
+
+TEST(TempDirTest, NotInEnvironment) {
+  SetEnv set_env("TEST_TMPDIR", nullptr);
+  EXPECT_NE(testing::TempDir(), "");
+}
+
+TEST(SrcDirTest, InEnvironment) {
+  // Since the test infrastructure might be verifying directory existence or
+  // even creating subdirectories, we need to be careful that the directories we
+  // specify are actually valid.
+  MakeTempDir temp_dir("SrcDirTest_InEnvironment");
+  SetEnv set_env("TEST_SRCDIR", temp_dir.DirName());
+  EXPECT_TRUE(StartsWith(testing::SrcDir(), temp_dir.DirName()));
+}
+
+TEST(SrcDirTest, NotInEnvironment) {
+  SetEnv set_env("TEST_SRCDIR", nullptr);
+  EXPECT_NE(testing::SrcDir(), "");
+}
+
+}  // namespace