build: strip trailing whitespace in docs (#17488)

script/check-trailing-whitespace.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python
+
+import os
+import sys
+
+SOURCE_ROOT = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
+DOCS_DIR = os.path.join(SOURCE_ROOT, 'docs')
+
+def main():
+  os.chdir(SOURCE_ROOT)
+
+  filepaths = []
+  totalDirs = 0
+  try:
+    for root, dirs, files in os.walk(DOCS_DIR):
+      totalDirs += len(dirs)
+      for f in files:
+        if f.endswith('.md'):
+          filepaths.append(os.path.join(root, f))
+  except KeyboardInterrupt:
+    print('Keyboard interruption. Please try again.')
+    return
+
+  trailingWhiteSpaceFiles = 0
+  for path in filepaths:
+    trailingWhiteSpaceFiles += hasTrailingWhiteSpace(path)
+
+  print('Parsed through ' + str(len(filepaths)) +
+        ' files within docs directory and its ' +
+        str(totalDirs) + ' subdirectories.')
+  print('Found ' + str(trailingWhiteSpaceFiles) +
+        ' files with trailing whitespace.')
+  return trailingWhiteSpaceFiles
+
+def hasTrailingWhiteSpace(filepath):
+  try:
+    f = open(filepath, 'r')
+    lines = f.read().splitlines()
+  except KeyboardInterrupt:
+    print('Keyboard interruption whle parsing. Please try again.')
+  finally:
+    f.close()
+
+  for line in lines:
+    if line != line.rstrip():
+      print "Trailing whitespace in: " + filepath
+      return True
+
+  return False
+
+if __name__ == '__main__':
+  sys.exit(main())