Use the env TEMPDIR if available instead of P_tmpdir.

CHANGELOG.md

@@ -7,6 +7,7 @@
 * Fixed forgetting to insert a backlink when inserting a mixed link directly using Table::FieldValues. ([#4899](https://github.com/realm/realm-core/issues/4899) since the introduction of Mixed in v11.0.0)
 * Using "sort", "distinct", or "limit" as field name in query expression would cause an "Invalid predicate" error ([#7545](https://github.com/realm/realm-java/issues/7545) since v10.1.2)
 * Crash when quering with 'Not()' followed by empty group. ([#4168](https://github.com/realm/realm-core/issues/4168) since v1.0.0)
+* Change Apple/Linux temp dir created with `util::make_temp_dir()` to default to the environment's TMPDIR if available. Make `TestFile` clean up the directories it creates when finished. ([#4921](https://github.com/realm/realm-core/issues/4921))
 
 ### Breaking changes
 * `App::Config::transport_factory` was replaced with `App::Config::transport`. It should now be an instance of `GenericNetworkTransport` rather than a factory for making instances. This allows the SDK to control which thread constructs the transport layer. ([#4903](https://github.com/realm/realm-core/pull/4903))

src/realm/util/file.cpp

@@ -322,7 +322,12 @@ std::string make_temp_dir()
     }
     return std::string(buffer);
 #else
-    std::string tmp = std::string(P_tmpdir) + std::string("/realm_XXXXXX") + std::string("\0", 1);
+    char* tmp_dir_env = getenv("TMPDIR");
+    std::string base_dir = tmp_dir_env ? tmp_dir_env : std::string(P_tmpdir);
+    if (!base_dir.empty() && base_dir[base_dir.length() - 1] != '/') {
+        base_dir = base_dir + "/";
+    }
+    std::string tmp = base_dir + std::string("realm_XXXXXX") + std::string("\0", 1);
     std::unique_ptr<char[]> buffer = std::make_unique<char[]>(tmp.size()); // Throws
     memcpy(buffer.get(), tmp.c_str(), tmp.size());
     if (mkdtemp(buffer.get()) == 0) {

test/object-store/migrations.cpp

@@ -2266,13 +2266,12 @@ TEST_CASE("migration: AdditiveDiscovered") {
          }},
     };
 
-    TestFile config;
-    config.cache = false;
-    config.schema = schema;
-
     std::vector<SchemaMode> additive_modes = {SchemaMode::AdditiveDiscovered, SchemaMode::AdditiveExplicit};
 
     for (auto mode : additive_modes) {
+        TestFile config;
+        config.cache = false;
+        config.schema = schema;
         config.schema_mode = mode;
         auto realm = Realm::get_shared_realm(config);
         realm->update_schema(schema);

test/object-store/util/test_file.cpp

@@ -61,7 +61,11 @@ using namespace realm;
 TestFile::TestFile()
 {
     disable_sync_to_disk();
-    path = util::format("%1/realm.XXXXXX", util::make_temp_dir());
+    m_temp_dir = util::make_temp_dir();
+    if (m_temp_dir.size() == 0 || m_temp_dir[m_temp_dir.size() - 1] != '/') {
+        m_temp_dir = m_temp_dir + "/";
+    }
+    path = util::format("%1realm.XXXXXX", m_temp_dir);
     int fd = mkstemp(path.data());
     if (fd < 0) {
         int err = errno;
@@ -80,12 +84,10 @@ TestFile::TestFile()
 
 TestFile::~TestFile()
 {
-    if (!m_persist)
-#ifdef _WIN32
-        _unlink(path.c_str());
-#else // POSIX
-        unlink(path.c_str());
-#endif
+    if (!m_persist) {
+        util::File::try_remove(path);
+        util::try_remove_dir_recursive(m_temp_dir);
+    }
 }
 
 DBOptions TestFile::options() const

test/object-store/util/test_file.hpp

@@ -82,6 +82,7 @@ struct TestFile : realm::Realm::Config {
 
 private:
     bool m_persist = false;
+    std::string m_temp_dir;
 };
 
 struct InMemoryTestFile : TestFile {