test: factor out mtree parser

test/compat_test.cpp

@@ -1085,31 +1085,12 @@ void check_compat(logger& lgr, reader::filesystem_v2 const& fs,
   EXPECT_NO_THROW(ext.extract(fs));
   EXPECT_NO_THROW(ext.close());
 
-  std::istringstream iss(oss.str());
-  std::string line;
-  size_t num = 0;
   ref_entries.erase("");
 
-  while (std::getline(iss, line, '\n')) {
+  auto mtree = test::parse_mtree(oss.str());
-    if (line == "#mtree") {
-      continue;
-    }
 
-    std::vector<std::string> parts;
+  for (auto [path, kv] : mtree) {
-    split_to(line, ' ', parts);
+    auto name = path.substr(2);
-    auto name = parts.front().substr(2);
-    parts.erase(parts.begin());
-    std::unordered_map<std::string, std::string> kv;
-
-    for (auto const& p : parts) {
-      auto pos = p.find('=');
-      if (pos == std::string::npos) {
-        throw std::runtime_error("unexpected mtree line: " + line);
-      }
-      kv[p.substr(0, pos)] = p.substr(pos + 1);
-    }
-
-    ++num;
 
     auto ri = ref_entries.find(name);
     EXPECT_FALSE(ri == ref_entries.end());
@@ -1127,7 +1108,7 @@ void check_compat(logger& lgr, reader::filesystem_v2 const& fs,
     }
   }
 
-  EXPECT_EQ(ref_entries.size(), num);
+  EXPECT_EQ(ref_entries.size(), mtree.size());
 
   std::map<std::string, std::vector<std::string>> testdirs{
       {"empty", {"empty/alsoempty"}},

test/test_helpers.cpp

@@ -576,6 +576,40 @@ std::string create_random_string(size_t size, size_t seed) {
   return create_random_string(size, tmprng);
 }
 
+std::vector<
+    std::pair<std::string, std::unordered_map<std::string, std::string>>>
+parse_mtree(std::string_view mtree) {
+  std::vector<
+      std::pair<std::string, std::unordered_map<std::string, std::string>>>
+      rv;
+  std::istringstream iss{std::string{mtree}};
+  std::string line;
+
+  while (std::getline(iss, line, '\n')) {
+    if (line == "#mtree") {
+      continue;
+    }
+
+    auto parts = split_to<std::vector<std::string>>(line, ' ');
+    auto path = parts.front();
+    parts.erase(parts.begin());
+
+    std::unordered_map<std::string, std::string> attrs;
+
+    for (auto const& p : parts) {
+      auto pos = p.find('=');
+      if (pos == std::string::npos) {
+        throw std::runtime_error("unexpected mtree line: " + line);
+      }
+      attrs[p.substr(0, pos)] = p.substr(pos + 1);
+    }
+
+    rv.emplace_back(std::move(path), std::move(attrs));
+  }
+
+  return rv;
+}
+
 bool skip_slow_tests() {
   static bool skip = getenv_is_enabled("DWARFS_SKIP_SLOW_TESTS");
   return skip;

test/test_helpers.h

@@ -364,6 +364,10 @@ std::string create_random_string(size_t size, uint8_t min, uint8_t max,
 std::string create_random_string(size_t size, std::mt19937_64& gen);
 std::string create_random_string(size_t size, size_t seed = 0);
 
+std::vector<
+    std::pair<std::string, std::unordered_map<std::string, std::string>>>
+parse_mtree(std::string_view mtree);
+
 bool skip_slow_tests();
 
 #define DWARFS_SLOW_TEST()                                                     \