Add a test reproducing micrometer-metrics/micrometer#3020

src/test/java/learningtest/io/micrometer/core/instrument/composite/CompositeMeterRegistryTests.java

@@ -2,7 +2,9 @@
 
 import io.micrometer.core.instrument.Counter;
 import io.micrometer.core.instrument.composite.CompositeMeterRegistry;
+import io.micrometer.core.instrument.config.MeterFilter;
 import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -28,4 +30,25 @@ void test() {
         assertThat(childMeterRegistry.counter(name).count()).isOne();
     }
 
+    @Disabled("See https://github.com/micrometer-metrics/micrometer/issues/3020")
+    @Test
+    void filtersOnIntermediateCompositeMeterRegistryDoNotSeemToWork() {
+        CompositeMeterRegistry parentMeterRegistry = new CompositeMeterRegistry();
+
+        CompositeMeterRegistry intermediateMeterRegistry = new CompositeMeterRegistry();
+        intermediateMeterRegistry.config().meterFilter(MeterFilter.denyNameStartsWith("deny"));
+        parentMeterRegistry.add(intermediateMeterRegistry);
+
+        SimpleMeterRegistry leafMeterRegistry = new SimpleMeterRegistry();
+        intermediateMeterRegistry.add(leafMeterRegistry);
+
+        parentMeterRegistry.counter("deny.item");
+
+        assertThat(parentMeterRegistry.getMeters()).hasSize(1);
+        // This seems to be empty with and without the filter.
+        assertThat(intermediateMeterRegistry.getMeters()).isEmpty();
+        // Filters on intermediate composite meter registries don't seem to work.
+        assertThat(leafMeterRegistry.getMeters()).isEmpty();
+    }
+
 }