Restore the Error middleware's two defaults without restating every option

[ericproulx]

Middleware::Error::Options lists its fourteen options as Data members and again as keyword parameters with their defaults. Two of them, rescue_options and default_error_formatter, arrive as an explicit nil from Endpoint#error_middleware_options when the API called no rescue_from and no format. An explicit nil bypasses a keyword default, so initialize restored the two by hand, in a super call that named all fourteen options a third time.

Change

rescue_options ||= Grape::DSL::RescueOptions.new
default_error_formatter ||= Grape::ErrorFormatter::Txt
super

A bare super passes the method's parameters as they stand, reassigned ones included. Checked on Ruby 4.0.7: explicit nils for the other options still go through as nil, an unknown keyword still raises, and positional construction and #with still work. The comment no longer points at the def_delegator :rescue_options, :backtrace that #initialize replaced with an instance variable.

Not changed: the readers and the instance-variable copy

The middleware lists the options twice more, in attr_reader and in the assignments in #initialize. Both could come from Options.members, but a loop costs build time. Copying through instance_variable_set made Error.new 43% slower in the interpreter and 49% with YJIT. With the instance-variable names precomputed and the values read off options, it was still 14% and 23% slower. Compiling a 200-route API was 1.7% and 2.8% slower in every run. Generating the assignments with class_eval would cost nothing, but Grape has no string-eval code generation, and a tidy-up is not a reason to introduce it. The lists stay written out.

Tests

No spec changes; behaviour is unchanged.

• bundle exec rake passes.
• Removing either restored default fails the suite: 1584 examples without rescue_options, 34 without default_error_formatter.
• A script built Error and Formatter bare, with explicit nils and with every option set, on master and on this branch. It dumped instance variables (names and order), reader values and #options; the dumps are identical.
• Error.new throughput, master vs branch run alternately, two rounds: interpreter 350k → 355k, YJIT 480k → 464k. Master's own two YJIT rounds were 461k and 500k, so this is noise.

🤖 Generated with Claude Code

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