[TASK] Add non-working test cases for BooleanParser (#955)

As this is a more complicated issue, we first provide test cases and
disable them for now.

Related issue: #533

tests/Functional/ViewHelpers/IfThenElseViewHelperTest.php

@@ -490,6 +490,15 @@ public static function renderDataProvider(): \Generator
             ['verdict' => false],
             0,
         ];
+        /**
+         * @todo This should work but doesn't at the moment. This is probably related to the boolean
+         * parser not converting variable nodes correctly. There is a related todo in the BooleanParserTest.
+        yield 'test' => [
+            '<f:if condition="{test}"><f:then>then</f:then><f:else>else</f:else></f:if>',
+            ['test' => '""'],
+            'then',
+        ];
+         */
     }
 
     #[DataProvider('renderDataProvider')]

tests/Unit/Core/Parser/BooleanParserTest.php

@@ -104,6 +104,12 @@ public static function getSomeEvaluationTestValues(): array
             ['{foo}', true, ['foo' => true]],
             ['{foo} == FALSE', true, ['foo' => false]],
             ['!{foo}', true, ['foo' => false]],
+
+            /*
+             * @todo This should work but doesn't at the moment. This is probably related to the boolean
+             * parser not converting variable nodes correctly. There is a related todo in the IfThenElseViewHelperTest.
+            ['{foo}', true, ['foo' => '""']],
+             */
         ];
     }