Intent to ship: JSON.parse with source

[Bryan Thrall]

As of Firefox 131, I intend to turn JSON.parse with source on by default on all desktop platforms. It has been developed behind the javascript.options.experimental.json_parse_with_source preference. The API shipped in Chromium last year (https://chromestatus.com/feature/5121582673428480), and implementation in WebKit is underway (https://bugs.webkit.org/show_bug.cgi?id=248031).

Bug to turn on by default: http://bugzilla.mozilla.org/show_bug.cgi?id=1913085 is the bug to enable, and https://bugzilla.mozilla.org/show_bug.cgi?id=1658310 is the meta bug for this.

Standard: https://tc39.es/proposal-json-parse-with-source

This feature was previously discussed in this "Intent to prototype" thread: https://groups.google.com/a/mozilla.org/g/dev-platform/c/R9UUdVUuUGU/m/H3e_Me1XAAAJ

Let me know if you have any questions,

[Bryan Thrall]

This change landed in Firefox Nightly 132, rather than 131.

-- 
Bryan Thrall
Senior Software Engineer
Mozilla

[Bryan Thrall]

We discovered some performance issues with this implementation, so I'm going to disable the feature by default in Firefox 132 until we can get the issues resolved.

[Bryan Thrall]

We are now planning on shipping Firefox 135 with JSON.parse enabled by default on all desktop platforms.

Here is the bug to turn it on by default: https://bugzilla.mozilla.org/show_bug.cgi?id=1934622

Let me know if you have any questions!