Enforce parentheses on method calls with arguments

[anakinj]

Description

Style/MethodCallWithArgsParentheses is off by default, so the codebase had drifted both ways — JWT.encode payload, nil, alg sitting next to JWT.encode(payload, nil, alg), with the paren-less form concentrated in the older specs. This enables the cop and applies it.

Style/MethodCallWithArgsParentheses:
  Enabled: true
  Exclude:
    - "*.gemspec"
  AllowedMethods:
    - raise
    - fail
    - yield
    - to
    - not_to
    - to_not
    - describe
    - context
    - it
    - specify

What is deliberately left alone

raise and fail. raise Foo, 'msg' is about as idiomatic as paren-less Ruby gets, and enforcing parentheses on it accounted for 67 of the 100 changed lines in lib/ — all of it in the claims and crypto files, for a style nobody asked for. The codebase is already mixed here (crit.rb and jwt_id.rb use parentheses, audience.rb and expiration.rb do not) and stays that way, unenforced. Exempting these is what takes lib/ from 100 changed lines down to 7.

yield. A keyword that reads like one; yield('msg') is no clearer than yield 'msg'.

The gemspec. spec.add_dependency 'base64' is the universal form and the whole file is a DSL. Metrics/BlockLength already excludes it.

The RSpec matcher DSL. Without the exemptions the autocorrect produces RSpec.describe(JWT) and expect(x).to(eq(y)), which is worse than what it replaces.

Scope

21 files, 226 insertions / 225 deletions. lib/ is down to four calls:

exported.reject! { |k, _| EC_PRIVATE_KEY_ELEMENTS.include? k }   ->  .include?(k)   (x3)
l = a.unpack "C#{a.bytesize}"                                    ->  a.unpack("C#{a.bytesize}")

The one hand-written part

Everything else is rubocop -a output, except five arrays in spec/integration/readme_examples_spec.rb. Adding parentheses there made Layout/FirstArrayElementIndentation push the elements out to a 36 column hanging indent:

expect(decoded_token).to eq([
                              { 'data' => 'test' },
                              { 'alg' => 'none' }
                            ])

They are collapsed onto one line instead. Switching Layout/FirstArrayElementIndentation to consistent was the other way to fix that, but it restyles 14 places to fix 5.

Verification

• 644 examples, 0 failures. RuboCop clean, 93 files, no offenses.
• Syntactic only: no method call changes arity, receiver or arguments.

Checklist

Before the PR can be merged be sure the following are checked:

• There are tests for the fix or feature added/changed — n/a, no behaviour change
• A description of the changes and a reference to the PR has been added to CHANGELOG.md — skipped, style-only with no effect on the published gem