Support variable debugging for JavaScript

Author: bennyyip

README.md

@@ -57,7 +57,7 @@ Fortran      | :heavy_check_mark: | :heavy_check_mark:
 Go           | :x:                | :x:
 Haskell      | :heavy_check_mark: | :heavy_check_mark:
 Java         | :heavy_check_mark: | :heavy_check_mark:
-Javascript   | :heavy_check_mark: | :x:
+Javascript   | :heavy_check_mark: | :heavy_check_mark:
 Julia        | :x:                | :x:
 Lua          | :x:                | :x:
 Matlab       | :x:                | :x:

ftplugin/javascript.vim

@@ -3,4 +3,12 @@ function! s:DebugStringFun()
     :return l:debug_str
 endfunc
 
+function! s:DebugVarFun(desc, var)
+    let l:debug_str = 'console.log(`' . a:desc . '${' . a:var . '}`)'
+    return l:debug_str
+endfunc
+
+
 command! -buffer -nargs=0 AddDebugString put=s:DebugStringFun()
+command! -buffer -nargs=1 AddDebugStringExpr
+            \ put=s:DebugVarFun(<args> . ': ', <args>)