Increase test coverage

Author: beutlich

.CI/Test/FileSystem.c

@@ -4,8 +4,23 @@
 #include <assert.h>
 #include <string.h>
 
+typedef enum {
+    FileType_NoFile = 1,
+    FileType_Directory = 3
+} ModelicaFileType;
+
 int main(int argc, char **argv) {
-    ModelicaInternal_mkdir("abc");
-    ModelicaInternal_rmdir("abc");
+    const char* dirName = "abc";
+    const char* newName = "xyz";
+    ModelicaFileType fileType = FileType_NoFile;
+    ModelicaInternal_mkdir(dirName);
+    fileType = ModelicaInternal_stat(dirName);
+    assert(FileType_Directory == fileType);
+    ModelicaInternal_rename(dirName, newName);
+    fileType = ModelicaInternal_stat(dirName);
+    assert(FileType_NoFile == fileType);
+    fileType = ModelicaInternal_stat(newName);
+    assert(FileType_Directory == fileType);
+    ModelicaInternal_rmdir(newName);
     return 0;
 }