subject
バランスの取れていない (エスケープされていない) 引用符が含まれていない場合にのみ、文字列 ( ) に一致する正規表現が必要な場合は、次のことを試してください。
/^(?:[^"\\]|\\.|"(?:\\.|[^"\\])*")*$/.test(subject)
説明:
^ # Match the start of the string.
(?: # Match either...
[^"\\] # a character besides quotes or backslash
| # or
\\. # any escaped character
| # or
" # a closed string, i. e. one that starts with a quote,
(?: # followed by either
\\. # an escaped character
| # or
[^"\\] # any other character except quote or backslash
)* # any number of times,
" # and a closing quote.
)* # Repeat as often as needed.
$ # Match the end of the string.