Improve get all files in directory unit test (AcademySoftwareFoundation#2666)

Inverting the logic to compare file list to account for possible OS level files like .DS_Store

Author: ld-kerley

source/MaterialXFormat/File.cpp

@@ -185,7 +185,7 @@ FilePathVec FilePath::getFilesInDirectory(const string& extension) const
 
 #if defined(_WIN32)
     WIN32_FIND_DATAA fd;
-    FilePath query = extension.empty() ? *this : (*this / ("*." + extension));
+    FilePath query = extension.empty() ? (*this / "*") : (*this / ("*." + extension));
     HANDLE hFind = FindFirstFileA(query.asString().c_str(), &fd);
     if (hFind != INVALID_HANDLE_VALUE)
     {

source/MaterialXTest/MaterialXFormat/File.cpp

@@ -185,20 +185,23 @@ TEST_CASE("Get all files in directory", "[file]")
     mx::FilePathVec results;
 
     results = lightsDir.getFilesInDirectory("mtlx");
-    for (const mx::FilePath& filename : results)
+    REQUIRE(results.size() > 0);
+    for (const mx::FilePath& filename : mtlxFilenames)
     {
-        REQUIRE(std::find(mtlxFilenames.begin(), mtlxFilenames.end(), filename) != mtlxFilenames.end());
+        REQUIRE(std::find(results.begin(), results.end(), filename) != results.end());
     }
 
     results = lightsDir.getFilesInDirectory("hdr");
-    for (const mx::FilePath& filename : results)
+    REQUIRE(results.size() > 0);
+    for (const mx::FilePath& filename : hdrFilenames)
     {
-        REQUIRE(std::find(hdrFilenames.begin(), hdrFilenames.end(), filename) != hdrFilenames.end());
+        REQUIRE(std::find(results.begin(), results.end(), filename) != results.end());
     }
 
     results = lightsDir.getFilesInDirectory();
-    for (const mx::FilePath& filename : results)
+    REQUIRE(results.size() > 0);
+    for (const mx::FilePath& filename : allFilesnames)
     {
-        REQUIRE(std::find(allFilesnames.begin(), allFilesnames.end(), filename) != allFilesnames.end());
+        REQUIRE(std::find(results.begin(), results.end(), filename) != results.end());
     }
 }