I had to write my own JSON parser/formatter a year ago (to support Java 1.2 - don't ask) and this article and its supporting github repo (https://github.com/nst/JSONTestSuite) was an unexpected gift from the heavens.
Doesn’t the test suite’s matrix demonstrate that there are tons of cases that aren’t handled consistently across these parsers?
If you're emitting JSON you can skim the list and avoid all of them.
Either way the minefield proper is no longer your problem.
So it certainly helped me. And just based on how thorough and insane the test suite is, I think I'm in good hands. Not perfect hands - but definitely a million times better than anything I would have come up with on my own.
The test suite made my parser blow up many times, and for each blow up I got to make a conscious decision in my bugfix: how do I want to handle this?
(I decided to let the 10,000 depth nested {{{{{{{{{{{{{{{{{{"key","value"}}}}}}}}}}}}}}}}}}} guy blow up even though it is legal. Yes, I'm too lazy to implement my own stack.) :-)