@@ -19,7 +19,13 @@ class impl : public installer_ifc {

             const directory &directory, const installer_ifc::generator &generator) :

             tokens_(tokens), unistd_(unistd), directory_(directory), generator_(generator) {}

         std::string install_token() const override {

-            std::string user_name = unistd_.getlogin();

+            const char *c_user_name = unistd_.getlogin();

+            if (c_user_name == nullptr) {

+                return "";

+            }

+

+            std::string user_name = c_user_name;

+

             auto found_user = directory_.find_user(user_name);

             user user(found_user[0]);

             std::string token(generator_());

@@ -26,6 +26,13 @@ class fake_unistd : public unistd_ifc {

         }

 };

+class fail_unistd : public unistd_ifc {

+    public:

+        const char *getlogin() const override {

+            return nullptr;

+        }

+};

+

 class fake_directory : public directory_ifc {

     private:

         std::string expected_user_name_;

@@ -63,10 +70,30 @@ int installs_token() {

     succeed();

 }

+int unistd_does_not_find_user_name() {

+    //given

+    std::string user_name("user");

+    std::string token("token");

+    auto  test_tokens = std::make_shared<mock_tokens>();

+    tokens tokens{test_tokens};

+    unistd unistd(std::make_shared<fail_unistd>());

+    directory directory(std::make_shared<fake_directory>(user_name));

+    installer_ifc::generator generator = [&] { return token; };

+

+    installer installer = installer::create (tokens, unistd, directory, generator);

+

+

+    //when

+    installer.install_token();

+    //then

+    check(test_tokens->captured_token == "", "should not have installed a token");

+    succeed();

+}

 int run_tests() {

     test(installs_token);

+    test(unistd_does_not_find_user_name);

     succeed();

 }