diff --git a/CMakeLists.txt b/CMakeLists.txt
index 35a08c2..663dbe4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,6 +24,7 @@ enable_testing()
 add_executable(wavefront_tests
 	tests/unit/trim_test.cpp
 	tests/unit/settings_test.cpp
+	tests/unit/scan_test.cpp
 	${APP_SOURCES}
 )
 target_link_libraries(wavefront_tests PRIVATE
diff --git a/src/main.cpp b/src/main.cpp
index 53b16f5..267bc40 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -124,10 +124,10 @@ int main(int argc, char** argv) {
     using FloatType = float;
     using IndexType = std::uint32_t;
 
-    CATCH_AND_RETURN(scan_data, wavefront::scan_error, 1, wavefront::scan(
+    auto scan_data = wavefront::scan(
         settings.input(),
         settings.selected_objects(),
-        settings.selected_groups())
+        settings.selected_groups()
     );
 
     std::cerr << "Scanned " << scan_data.total_lines << " lines" << std::endl;
diff --git a/src/scan.cpp b/src/scan.cpp
index a5ee70e..790249a 100644
--- a/src/scan.cpp
+++ b/src/scan.cpp
@@ -11,8 +11,6 @@
 #include "scan.hpp"
 
 namespace wavefront {
-    scan_error::scan_error(const std::string &message) : std::runtime_error(message) {}
-
     scan_result::scan_result() :
         total_lines(0),
         line_data(),
diff --git a/src/scan.hpp b/src/scan.hpp
index 77f9d96..4541c27 100644
--- a/src/scan.hpp
+++ b/src/scan.hpp
@@ -10,11 +10,6 @@
 #include "settings.hpp"
 
 namespace wavefront {
-    class scan_error : public std::runtime_error {
-    public:
-        explicit scan_error(const std::string &message);
-    };
-
     struct scan_result {
         std::size_t total_lines;
         std::map<std::size_t, std::string> line_data;
diff --git a/tests/data/test-scan-1.txt b/tests/data/test-scan-1.txt
index 4223d07..325e095 100644
--- a/tests/data/test-scan-1.txt
+++ b/tests/data/test-scan-1.txt
@@ -1,4 +1,5 @@
 # Command
+
 v 0.1 0.2 0.3
 v 0.2 0.3 0.4
 v 0.3 0.4 0.5
@@ -18,3 +19,8 @@ o test
 f 4/3/2 5/2/1 6/1/2
 g test
 f 7/2/2 8/3/2 9/1/1
+o
+f 8/1/1 5/2/2 3/3/2
+g
+f 2/1/1 6/2/2 4/3/2
+h this line is skipped
diff --git a/tests/unit/scan_test.cpp b/tests/unit/scan_test.cpp
new file mode 100644
index 0000000..1f17e2a
--- /dev/null
+++ b/tests/unit/scan_test.cpp
@@ -0,0 +1,64 @@
+#include <filesystem>
+#include <fstream>
+
+#include <gtest/gtest.h>
+
+#include "scan.hpp"
+
+namespace {
+    std::filesystem::path test_data_path(const std::string &filename) {
+        const auto here = std::filesystem::path(__FILE__).parent_path();
+        return here.parent_path() / "data" / filename;
+    }
+
+    TEST(Scan, ReadsAllSupportedTypes) {
+        std::ifstream input(test_data_path("test-scan-1.txt"));
+        ASSERT_TRUE(input.is_open());
+
+        const auto result = wavefront::scan(input);
+
+        EXPECT_EQ(result.total_lines, 26u);
+        EXPECT_EQ(result.line_data.size(), 21u);
+
+        EXPECT_TRUE(result.category_map.contains("v"));
+        EXPECT_TRUE(result.category_map.contains("vn"));
+        EXPECT_TRUE(result.category_map.contains("vt"));
+        EXPECT_TRUE(result.category_map.contains("f"));
+
+        EXPECT_EQ(result.category_map.at("v").size(), 10u);
+        EXPECT_EQ(result.category_map.at("vn").size(), 4u);
+        EXPECT_EQ(result.category_map.at("vt").size(), 3u);
+        EXPECT_EQ(result.category_map.at("f").size(), 5u);
+    }
+
+    TEST(Scan, FiltersByObject) {
+        std::ifstream input(test_data_path("test-scan-1.txt"));
+        ASSERT_TRUE(input.is_open());
+
+        const auto result = wavefront::scan(input, {"test"});
+
+        EXPECT_EQ(result.category_map.at("f").size(), 4u);
+        EXPECT_EQ(result.category_map.at("f")[0], 19u);
+        EXPECT_EQ(result.category_map.at("f")[1], 21u);
+    }
+
+    TEST(Scan, FiltersByGroup) {
+        std::ifstream input(test_data_path("test-scan-1.txt"));
+        ASSERT_TRUE(input.is_open());
+
+        const auto result = wavefront::scan(input, {}, {"test"});
+
+        EXPECT_EQ(result.category_map.at("f").size(), 3u);
+        EXPECT_EQ(result.category_map.at("f")[0], 21u);
+    }
+
+    TEST(Scan, FiltersByObjectAndGroup) {
+        std::ifstream input(test_data_path("test-scan-1.txt"));
+        ASSERT_TRUE(input.is_open());
+
+        const auto result = wavefront::scan(input, {"test"}, {"test"});
+
+        EXPECT_EQ(result.category_map.at("f").size(), 3u);
+        EXPECT_EQ(result.category_map.at("f")[0], 21u);
+    }
+}