Cleanup some filesystem tests. NFC

There were a couple of old tests in `test/filesystem`.  This change
modes them to `test/fs` and improves them.

Author: sbc100

test/filesystem/bad_lookup.cpp

@@ -0,0 +1,81 @@
+// Copyright 2014 The Emscripten Authors.  All rights reserved.
+// Emscripten is available under two separate licenses, the MIT license and the
+// University of Illinois/NCSA Open Source License.  Both these licenses can be
+// found in the LICENSE file.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+//--------------------------------------------------------------------------
+// Helper to create an empty file with the given path.
+void touch(const char* path, const mode_t mode) {
+  printf("Touching file: %s with mode=%o\n", path, mode);
+
+  int fd = open(path, O_CREAT | O_WRONLY, mode);
+  if (fd == -1) {
+    int error = errno;
+    printf("Failed to touch file using open: %s; %s\n", path, strerror(errno));
+  } else {
+    close(fd);
+  }
+}
+
+//--------------------------------------------------------------------------
+// Stats the given path and prints the mode.  Returns true if the path
+// exists; false otherwise.
+bool exists(const char* path) {
+  struct stat path_stat;
+  if (lstat(path, &path_stat) != 0) {
+    int error = errno;
+    if (error == ENOENT) {
+      // Only bother logging if something other than the path not existing
+      // went wrong.
+      printf("Failed to lstat path: %s; %s", path, strerror(error));
+    }
+    return false;
+  }
+
+  printf("Mode for path=%s: %o\n", path, path_stat.st_mode);
+  return true;
+}
+
+int main() {
+  touch("file1", 0667);
+  if (!exists("file1")) {
+    printf("Failed to create path: file1\n");
+    return 1;
+  }
+  if (exists("file1/dir")) {
+    printf("Path should not exists: file1/dir\n");
+    return 1;
+  }
+
+  touch("file2", 0676);
+  if (!exists("file2")) {
+    printf("Failed to create path: file2\n");
+    return 1;
+  }
+  if (exists("file2/dir")) {
+    printf("Path should not exists: file2/dir\n");
+    return 1;
+  }
+
+  touch("file3", 0766);
+  if (!exists("file3")) {
+    printf("Failed to create path: file3\n");
+    return 1;
+  }
+  if (exists("file3/dir")) {
+    printf("Path should not exists: file3/dir\n");
+    return 1;
+  }
+
+  printf("ok.\n");
+  return 0;
+}
+

test/fs/test_fs_bad_lookup.c

@@ -0,0 +1,4 @@
+int main() {
+  // Nothing to do here. Test is written in JS. See test/fs/test_fs_base.js.
+  return 0;
+}

test/fs/test_fs_base.c

@@ -195,3 +195,4 @@
   parentExists: false
   parentPath: null
   parentObject.contents: null
+

test/filesystem/src.js renamed to test/fs/test_fs_base.js

@@ -22,5 +22,6 @@ int main() {
   assert(nread == byte_count);
   fclose(fp);
 
+  printf("success\n");
   return 0;
 }

test/filesystem/output.txt renamed to test/fs/test_fs_base.out

@@ -813,7 +813,7 @@ def test():
 
   @also_with_wasmfs
   def test_dev_random(self):
-    self.btest_exit('filesystem/test_dev_random.c')
+    self.btest_exit('fs/test_dev_random.c')
 
   def test_sdl_swsurface(self):
     self.btest_exit('test_sdl_swsurface.c', args=['-lSDL', '-lGL'])

test/filesystem/test_dev_random.c renamed to test/fs/test_fs_dev_random.c

@@ -5735,10 +5735,8 @@ def test_istream(self):
 
   def test_fs_base(self):
     self.set_setting('DEFAULT_LIBRARY_FUNCS_TO_INCLUDE', ['$FS'])
-    self.add_pre_run(read_file(test_file('filesystem/src.js')))
-    src = 'int main() {return 0;}\n'
-    expected = read_file(test_file('filesystem/output.txt'))
-    self.do_run(src, expected)
+    self.add_pre_run(read_file(test_file('fs/test_fs_base.js')))
+    self.do_run_in_out_file_test('fs/test_fs_base.c')
 
   @also_with_noderawfs
   @is_slow_test

test/test_browser.py

@@ -6097,8 +6097,17 @@ class time_iterator {
     ''')
     self.run_process([EMXX, 'src.cpp', '-O2', '-sSAFE_HEAP'])
 
-  def test_bad_lookup(self):
-    self.do_runf(path_from_root('test/filesystem/bad_lookup.cpp'), expected_output='ok')
+  @also_with_wasmfs
+  @also_with_noderawfs
+  @crossplatform
+  def test_fs_bad_lookup(self):
+    self.do_runf(path_from_root('test/fs/test_fs_bad_lookup.c'), expected_output='ok')
+
+  @also_with_wasmfs
+  @also_with_noderawfs
+  @crossplatform
+  def test_fs_dev_random(self):
+    self.do_runf('fs/test_fs_dev_random.c', 'success')
 
   @parameterized({
     'none': [{'EMCC_FORCE_STDLIBS': None}, False],