Build scripts should allow lines that are purely whitespace (but not …

…non-whitespace with trailing whitespace)

build/tools/check-trailing-space-linux

@@ -3,7 +3,7 @@
 # Check that all files have trailing spaces stripped
 OutTrailingSpaceListFile='output/knockout-files-to-clean.txt'
 cd ..
-grep -rl ' $' build spec src | grep -v ".exe$" > build/$OutTrailingSpaceListFile
+grep -nrI '[^ ][ ]\+$' * | grep -rv "^build/output/" > build/$OutTrailingSpaceListFile
 cd build
 if [ -s $OutTrailingSpaceListFile ]
 then

build/tools/check-trailing-space-windows.bat

@@ -3,17 +3,17 @@
 @rem Check that all files have trailing spaces stripped
 set OutTrailingSpaceListFile=output\knockout-files-to-clean.txt
 cd ..
-findstr -rsm -c:" $" * |findstr -rv "^.git" |findstr -rv ".exe$" > build\%OutTrailingSpaceListFile%
-cd build
-for %%R in (%OutTrailingSpaceListFile%) do if %%~zR gtr 0 goto :NeedFixTrailingSpace
-del %OutTrailingSpaceListFile%
-goto :TrailingSpaceOkay
 
-:NeedFixTrailingSpace
-echo The following files have trailing spaces that need to be cleaned up:
-echo.
-type %OutTrailingSpaceListFile%
+@rem Totally outlandish way to detect trailing whitespace on non-whitespace-only lines, because the DOS "findstr" command can't handle spaces in regexes.
+@rem We should consider changing the whole Windows build script to PowerShell, where this would be trivial and clean.
+set foundTrailingWhitespace=0
+findstr -rsen -c:" " *.js *.html *.css *.bat *.ps1 > build\%OutTrailingSpaceListFile%
+cscript build\tools\searchReplace.js " {2,}" "" build\%OutTrailingSpaceListFile% >nul
+for /f "tokens=1,2,* delims=:" %%i in (build\%OutTrailingSpaceListFile%) do @if "%%k" NEQ "" (
+    echo Error: Trailing whitespace on %%i line %%j
+    set foundTrailingWhitespace=1
+)
+cd build
 del %OutTrailingSpaceListFile%
-exit /b 1
 
-:TrailingSpaceOkay
+if %foundTrailingWhitespace% EQU 1 exit /b 1