Bug #22241: Restore compatibility for removed `JSON.dump` and `JSON.parse` arguments

• Status: Open
• Assignee: byroot (Jean Boussier)
• Target version: 4.1
• ruby -v: f51515f39a13223ce784eb3412c1f83a8a3960a4
• Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN

[nobu (Nobuyoshi Nakada)]

JSON 3.0.0.rc1 removes two previously accepted arguments without a deprecation period:

JSON.dump(object, io, 0)
JSON.parse(source, quirks_mode: true)

The first call now raises TypeError because the third positional argument is treated as an options hash. The second raises ArgumentError because quirks_mode is no longer recognized.
Neither usage produces a deprecation warning with JSON 2.21.2, even with warnings enabled:

Warning[:deprecated] = true

This currently breaks downstream test suites. RDoc used the third JSON.dump argument when generating its JSON index, while json-schema 5.1.0 passes quirks_mode: true, causing RBS schema tests in the Ruby repository to fail.
Because JSON is a default gem, downstream projects cannot always avoid the breakage by pinning an older version, especially when testing against Ruby head. Could JSON 3.0 continue accepting these arguments for compatibility? quirks_mode can presumably be accepted and ignored now that top-level scalar values are parsed by default. The positional limit argument could similarly remain supported until it has gone through a deprecation cycle.

[byroot (Jean Boussier)]

quirks_mode hasn't been a valid argument for years. I can't even tell you what its behavior may have been.

Any code that pass quirks_mode should stop passing that argument, and it won't cause any compatibility.

As for the positional limit argument, this one I'm open to put it back, but the form JSON.dump(obj, max_nesting: <limit>) has been supported forever as well.

[byroot (Jean Boussier)]

Ref: https://github.com/byroot/json-schema/pull/1

[byroot (Jean Boussier)]

Could JSON 3.0 continue accepting these arguments for compatibility?

I'd prefer if Ruby kept using the 2.x-stable branch until ready: https://github.com/ruby/json/tree/2.x-stable

[nobu (Nobuyoshi Nakada)]

byroot (Jean Boussier) wrote in #note-1:

quirks_mode hasn't been a valid argument for years. I can't even tell you what its behavior may have been.

Any code that pass quirks_mode should stop passing that argument, and it won't cause any compatibility.

As for the positional limit argument, this one I'm open to put it back, but the form JSON.dump(obj, max_nesting: <limit>) has been supported forever as well.

I agree these arguments are useless , but also think it was problematic that the users had no chance to be noticed about them.

byroot (Jean Boussier) wrote in #note-2:

Ref: https://github.com/byroot/json-schema/pull/1

Not to the upstream?

[byroot (Jean Boussier)]

but also think it was problematic that the users had no chance to be noticed about them.

Well, I was planning to add deprecation for them in a new 2.x release soon. Right now it's a RC1, nobody is installing it without explicitly asking for it, except for ruby/ruby.

Not to the upstream?

Erf, I was tired, sorry: https://github.com/voxpupuli/json-schema/pull/578

I also started https://github.com/ruby/rbs/pull/3081