test(compliance): closure-to-single-method-interface coercion case

Languages with native closure-to-interface conversion (Java lambdas, and
now Ruby via Jsii::Utils.coerce_callable) can accept a bare closure where
a behavioral single-method interface is expected. Adds the suite case,
the Ruby spec exercising lambda / named-hash / static-call-site forms
end-to-end through the kernel, and the regenerated matrix.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: omarqureshi

gh-pages/content/specification/6-compliance-report.md

@@ -5,7 +5,7 @@
 This section details the current state of each language binding with respect to our standard compliance suite.
 
 
-| number | test                                                                                                                                                             | java (97.56%) | golang (78.86%)                              | dotnet (n/a) | python (n/a) | ruby (100.00%) |
+| number | test                                                                                                                                                             | java (96.77%) | golang (78.23%)                              | dotnet (n/a) | python (n/a) | ruby (100.00%) |
 | ------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------- | -------------------------------------------- | ------------ | ------------ | -------------- |
 | 1      | asyncOverrides_overrideCallsSuper                                                                                                                                | 🟢            | [🔴](https://github.com/aws/jsii/issues/2670) | n/a          | n/a          | 🟢             |
 | 2      | [arrayReturnedByMethodCanBeRead]("Array created in the kernel can be queried for its elements")                                                                  | 🟢            | 🟢                                           | n/a          | n/a          | 🟢             |
@@ -125,8 +125,9 @@ This section details the current state of each language binding with respect to
 | 116    | subclassing                                                                                                                                                      | 🟢            | 🟢                                           | n/a          | n/a          | 🟢             |
 | 117    | testInterfaces                                                                                                                                                   | 🟢            | 🟢                                           | n/a          | n/a          | 🟢             |
 | 118    | [callbackParameterIsInterface]("Validates pure interfaces can be passed to callbacks")                                                                           | ⭕             | 🟢                                           | n/a          | n/a          | 🟢             |
-| 119    | [classCanBeUsedWhenNotExpressedlyLoaded]("Validates that types not explicitly loaded by the user can safely be returned by JS code")                             | 🟢            | 🟢                                           | n/a          | n/a          | 🟢             |
-| 120    | [downcasting]("Ensures unsafe-cast features work as expected")                                                                                                   | ⭕             | 🟢                                           | n/a          | n/a          | 🟢             |
-| 121    | [strippedDeprecatedMemberCanBeReceived]("Ensures --strip-deprecated does not cause odd runtime errors")                                                          | 🟢            | 🟢                                           | n/a          | n/a          | 🟢             |
-| 122    | [exceptionMessage]("Verifies that custom exception names are correctly forwarded")                                                                               | 🟢            | 🟢                                           | n/a          | n/a          | 🟢             |
-| 123    | [voidReturningAsync]("Verifies that returning Promise<void> is correctly handled")                                                                               | ⭕             | ⭕                                            | n/a          | n/a          | 🟢             |
+| 119    | [closureImplementsSingleMethodInterface]("Language-native closures/lambdas can be passed where a behavioral single-method interface is expected")                | ⭕             | ⭕                                            | n/a          | n/a          | 🟢             |
+| 120    | [classCanBeUsedWhenNotExpressedlyLoaded]("Validates that types not explicitly loaded by the user can safely be returned by JS code")                             | 🟢            | 🟢                                           | n/a          | n/a          | 🟢             |
+| 121    | [downcasting]("Ensures unsafe-cast features work as expected")                                                                                                   | ⭕             | 🟢                                           | n/a          | n/a          | 🟢             |
+| 122    | [strippedDeprecatedMemberCanBeReceived]("Ensures --strip-deprecated does not cause odd runtime errors")                                                          | 🟢            | 🟢                                           | n/a          | n/a          | 🟢             |
+| 123    | [exceptionMessage]("Verifies that custom exception names are correctly forwarded")                                                                               | 🟢            | 🟢                                           | n/a          | n/a          | 🟢             |
+| 124    | [voidReturningAsync]("Verifies that returning Promise<void> is correctly handled")                                                                               | ⭕             | ⭕                                            | n/a          | n/a          | 🟢             |

packages/@jsii/ruby-runtime-test/spec/compliance/interfaces_spec.rb

@@ -238,6 +238,20 @@ def your_turn(bell)
     expect(consumer.when_typed_as_class(concrete_bell_ringer)).to be true
   end
 
+  it 'coerces closures into single-method interfaces', compliance: 'closureImplementsSingleMethodInterface' do
+    consumer = JsiiCalc::ConsumerCanRingBell.new
+
+    # Bare lambda where IBellRinger (single abstract method) is expected;
+    # the JS side calls back into it via the ordinary overrides path.
+    expect(consumer.implemented_by_object_literal(->(bell) { bell.ring })).to be true
+
+    # Named single-entry hash form, equivalent to the lambda.
+    expect(consumer.implemented_by_object_literal({ your_turn: ->(bell) { bell.ring } })).to be true
+
+    # Static call sites coerce the same way.
+    expect(JsiiCalc::ConsumerCanRingBell.static_implemented_by_object_literal(->(bell) { bell.ring })).to be true
+  end
+
   it 'builds guest objects implementing interface properties', compliance: 'interfaceBuilder' do
     klass = Class.new do
       include JsiiCalc::IInterfaceWithProperties

tools/jsii-compliance/suite.ts

@@ -510,6 +510,11 @@ export const suite: schema.Suite = {
       name: 'callbackParameterIsInterface',
       description: 'Validates pure interfaces can be passed to callbacks',
     },
+    {
+      name: 'closureImplementsSingleMethodInterface',
+      description:
+        'Language-native closures/lambdas can be passed where a behavioral single-method interface is expected',
+    },
     {
       name: 'classCanBeUsedWhenNotExpressedlyLoaded',
       description: