tools/file_packager.py: Cleanup code and and its generated output. NFC

tests/test_other.py

@@ -2497,18 +2497,33 @@ def test_file_packager(self):
     os.chdir('subdir')
     create_file('data2.txt', 'data2')
 
+    def check(text):
+      self.assertGreater(len(text), 0)
+      empty_lines = 0
+      # check the generated is relatively tidy
+      for line in text.splitlines():
+        if line and line[-1].isspace():
+          self.fail('output contains trailing whitespace: `%s`' % line)
+
+        if line.strip():
+          empty_lines = 0
+        else:
+          empty_lines += 1
+          if empty_lines > 1:
+            self.fail('output contains more then one empty line in row')
+
     # relative path to below the current dir is invalid
     stderr = self.expect_fail([FILE_PACKAGER, 'test.data', '--preload', '../data1.txt'])
     self.assertContained('below the current directory', stderr)
 
     # relative path that ends up under us is cool
     proc = self.run_process([FILE_PACKAGER, 'test.data', '--preload', '../subdir/data2.txt'], stderr=PIPE, stdout=PIPE)
-    self.assertGreater(len(proc.stdout), 0)
     self.assertNotContained('below the current directory', proc.stderr)
+    check(proc.stdout)
 
     # direct path leads to the same code being generated - relative path does not make us do anything different
     proc2 = self.run_process([FILE_PACKAGER, 'test.data', '--preload', 'data2.txt'], stderr=PIPE, stdout=PIPE)
-    self.assertGreater(len(proc2.stdout), 0)
+    check(proc2.stdout)
     self.assertNotContained('below the current directory', proc2.stderr)
 
     def clean(txt):