Allow for several directories in TEST_DATA_DIR

tests/CMakeLists.txt

@@ -180,7 +180,7 @@ if(AVIF_ENABLE_FUZZTEST)
         target_link_libraries(${TEST_NAME} PRIVATE aviftest_helpers ${ARGN})
         link_fuzztest(${TEST_NAME})
         add_test(NAME ${TEST_NAME} COMMAND ${TEST_NAME})
-        set_property(TEST ${TEST_NAME} PROPERTY ENVIRONMENT "TEST_DATA_DIR=${CMAKE_CURRENT_SOURCE_DIR}/data/")
+        set_property(TEST ${TEST_NAME} PROPERTY ENVIRONMENT "TEST_DATA_DIRS=${CMAKE_CURRENT_SOURCE_DIR}/data/")
     endmacro()
 
     if(AVIF_LOCAL_FUZZTEST)

tests/gtest/avif_fuzztest_dec.cc

@@ -21,7 +21,7 @@ ::testing::Environment* const kStackLimitEnv = SetStackLimitTo512x1024Bytes();
 //------------------------------------------------------------------------------
 
 void Decode(const std::string& arbitrary_bytes, DecoderPtr decoder) {
-  ASSERT_NE(GetSeedDataDir(), nullptr);  // Make sure seeds are available.
+  ASSERT_FALSE(GetSeedDataDirs().empty());  // Make sure seeds are available.
 
   ImagePtr decoded(avifImageCreateEmpty());
   ASSERT_NE(decoded, nullptr);

tests/gtest/avif_fuzztest_dec_incr.cc

@@ -46,7 +46,7 @@ avifResult AvifIoRead(struct avifIO* io, uint32_t read_flags, uint64_t offset,
 
 void DecodeIncr(const std::string& arbitrary_bytes, bool is_persistent,
                 bool give_size_hint, bool use_nth_image_api) {
-  ASSERT_NE(GetSeedDataDir(), nullptr);  // Make sure seeds are available.
+  ASSERT_FALSE(GetSeedDataDirs().empty());  // Make sure seeds are available.
 
   ImagePtr reference(avifImageCreateEmpty());
   ASSERT_NE(reference.get(), nullptr);

tests/gtest/avif_fuzztest_helpers.cc

@@ -213,43 +213,60 @@ ::testing::Environment* SetEnv(const char* name, const char* value) {
 
 //------------------------------------------------------------------------------
 
-const char* GetSeedDataDir() { return std::getenv("TEST_DATA_DIR"); }
+std::vector<std::string> GetSeedDataDirs() {
+  const char* var = std::getenv("TEST_DATA_DIRS");
+  std::vector<std::string> res;
+  if (var == nullptr || *var == 0) return res;
+  const char* var_start = var;
+  while (true) {
+    if (*var == 0 || *var == ';') {
+      res.push_back(std::string(var_start, var - var_start));
+      if (*var == 0) break;
+      var_start = var + 1;
+    }
+    ++var;
+  }
+  return res;
+}
 
 std::vector<std::string> GetTestImagesContents(
     size_t max_file_size, const std::vector<avifAppFileFormat>& image_formats) {
   // Use an environment variable to get the test data directory because
   // fuzztest seeds are created before the main() function is called, so the
   // test has no chance to parse command line arguments.
-  const char* const test_data_dir = GetSeedDataDir();
-  if (test_data_dir == nullptr) {
+  const std ::vector<std::string> test_data_dirs = GetSeedDataDirs();
+  if (test_data_dirs.empty()) {
     // Only a warning because this can happen when running the binary with
     // --list_fuzz_tests (such as with gtest_discover_tests() in cmake).
-    std::cerr << "WARNING: TEST_DATA_DIR env variable not set, unable to read "
+    std::cerr << "WARNING: TEST_DATA_DIRS env variable not set, unable to read "
                  "seed files";
     return {};
   }
 
-  std::cout << "Reading seeds from " << test_data_dir << " (non recursively)\n";
-  auto tuple_vector = fuzztest::ReadFilesFromDirectory(test_data_dir);
   std::vector<std::string> seeds;
-  seeds.reserve(tuple_vector.size());
-  for (auto& [file_content] : tuple_vector) {
-    if (file_content.size() > max_file_size) continue;
-    if (!image_formats.empty()) {
-      const avifAppFileFormat format = avifGuessBufferFileFormat(
-          reinterpret_cast<const uint8_t*>(file_content.data()),
-          file_content.size());
-      if (std::find(image_formats.begin(), image_formats.end(), format) ==
-          image_formats.end()) {
-        continue;
+  for (const std::string& test_data_dir : test_data_dirs) {
+    std::cout << "Reading seeds from " << test_data_dir
+              << " (non recursively)\n";
+    auto tuple_vector = fuzztest::ReadFilesFromDirectory(test_data_dir);
+    seeds.reserve(tuple_vector.size());
+    for (auto& [file_content] : tuple_vector) {
+      if (file_content.size() > max_file_size) continue;
+      if (!image_formats.empty()) {
+        const avifAppFileFormat format = avifGuessBufferFileFormat(
+            reinterpret_cast<const uint8_t*>(file_content.data()),
+            file_content.size());
+        if (std::find(image_formats.begin(), image_formats.end(), format) ==
+            image_formats.end()) {
+          continue;
+        }
       }
-    }
 
-    seeds.push_back(std::move(file_content));
+      seeds.push_back(std::move(file_content));
+    }
   }
   if (seeds.empty()) {
-    std::cerr << "ERROR: no files found in " << test_data_dir
-              << " that match the given file size and format criteria\n";
+    std::cerr << "ERROR: no files found that match the given file size and "
+                 "format criteria\n";
     std::abort();
   }
   std::cout << "Returning " << seeds.size() << " seed images\n";

tests/gtest/avif_fuzztest_helpers.h

@@ -195,31 +195,32 @@ inline ::testing::Environment* SetStackLimitTo512x1024Bytes() {
 
 //------------------------------------------------------------------------------
 
-// Returns the value of the 'TEST_DATA_DIR' environment variable.
+// Returns the paths contained in the 'TEST_DATA_DIRS' environment variable.
+// Several paths can be set in the variable, separated by ';'.
 // Returns nullptr if not set.
 // Tests that use ArbitraryImageWithSeeds() should
-// ASSERT_NE(GetSeedDataDir(), nullptr) if they want to make sure that seeds are
-// actually used.
-const char* GetSeedDataDir();
+// ASSERT_FALSE(GetSeedDataDirs().empty()) if they want to make sure that seeds
+// are actually used.
+std::vector<std::string> GetSeedDataDirs();
 
 // Returns a list of test images contents (not paths) from the directory set in
-// the 'TEST_DATA_DIR' environment variable, that are smaller than
+// the 'TEST_DATA_DIRS' environment variable, that are smaller than
 // 'max_file_size' and have one of the formats in 'image_formats' (or any format
 // if 'image_formats' is empty).
-// If TEST_DATA_DIR is not set, returns an empty set.
-// Tests that use this should ASSERT_NE(GetSeedDataDir(), nullptr)
+// If TEST_DATA_DIRS is not set, returns an empty set.
+// Tests that use this should ASSERT_FALSE(GetSeedDataDirs().empty())
 // if they want to make sure that seeds are actually used.
-// Terminates the program with abort() if TEST_DATA_DIR is set but doesn't
+// Terminates the program with abort() if TEST_DATA_DIRS is set but doesn't
 // contain any matching images.
 std::vector<std::string> GetTestImagesContents(
     size_t max_file_size, const std::vector<avifAppFileFormat>& image_formats);
 
 // Generator for an arbitrary ImagePtr that uses test image files as seeds.
-// Uses the 'TEST_DATA_DIR' environment variable to load the seeds.
-// If TEST_DATA_DIR is not set, no seeds are used.
-// Tests that use this should ASSERT_NE(GetSeedDataDir(), nullptr)
+// Uses the 'TEST_DATA_DIRS' environment variable to load the seeds.
+// If TEST_DATA_DIRS is not set, no seeds are used.
+// Tests that use this should ASSERT_FALSE(GetSeedDataDirs().empty())
 // if they want to make sure that seeds are actually used.
-// Terminates the program with abort() if TEST_DATA_DIR is set but doesn't
+// Terminates the program with abort() if TEST_DATA_DIRS is set but doesn't
 // contain any matching images.
 inline auto ArbitraryImageWithSeeds(
     const std::vector<avifAppFileFormat>& image_formats) {

tests/gtest/avif_fuzztest_read_image.cc

@@ -46,7 +46,7 @@ void ReadImageFile(const std::string& arbitrary_bytes,
                    bool ignore_color_profile, bool ignore_exif, bool ignore_xmp,
                    bool allow_changing_cicp, bool ignore_gain_map,
                    avifMatrixCoefficients matrix_coefficients) {
-  ASSERT_NE(GetSeedDataDir(), nullptr);  // Make sure seeds are available.
+  ASSERT_FALSE(GetSeedDataDirs().empty());  // Make sure seeds are available.
 
   // Write the byte stream to a temp file since avifReadImage() takes a file
   // path as input.