Ignore unsupported kty when a Set is built from an array (RFC 7517 §5)

lib/jwt/jwk/set.rb

@@ -28,7 +28,11 @@ def initialize(jwks = nil, options = {}) # rubocop:disable Metrics/CyclomaticCom
                     nil
                   end
                 when Array
-                  jwks.map { |k| JWT::JWK.new(k, nil, options) }
+                  jwks.each_with_object([]) do |k, arr|
+                    arr << JWT::JWK.new(k, nil, options)
+                  rescue JWT::UnsupportedKeyType
+                    nil
+                  end
                 else
                   raise ArgumentError, 'Can only create new JWKS from Hash, Array and JWK'
                 end

spec/jwt/jwk/set_spec.rb

@@ -48,6 +48,16 @@
       expect(set.keys[0][:kty]).to eql('oct')
     end
 
+    it 'ignores keys with unsupported kty values when constructed from an array (RFC 7517 §5)' do
+      keys = [
+        { kty: 'unknown', alg: 'unknown-alg', kid: 'unknown' },
+        { kty: 'oct', k: Base64.strict_encode64('testkey') }
+      ]
+      set = described_class.new(keys)
+      expect(set.size).to eql(1)
+      expect(set.keys[0][:kty]).to eql('oct')
+    end
+
     it 'returns an empty set when all keys have unsupported kty values' do
       jwks = {
         keys: [