Introduce InspectSink

This helps with writing unit tests.

blocks/basic/include/gnuradio-4.0/basic/common_blocks.hpp

@@ -10,6 +10,22 @@
 #include <gnuradio-4.0/Graph.hpp>
 #include <gnuradio-4.0/reflection.hpp>
 
+// A convenience class to make writing unit tests easier.
+// This sink allows to inspect the input port values as a class member.
+template<typename T>
+class InspectSink : public gr::Block<InspectSink<T>> {
+public:
+    T             value{};
+    gr::PortIn<T> in;
+
+    constexpr void
+    processOne(T val) {
+        value = val;
+    }
+};
+
+ENABLE_REFLECTION_FOR_TEMPLATE_FULL((typename T), (InspectSink<T>), value, in);
+
 template<typename T>
 class builtin_multiply : public gr::Block<builtin_multiply<T>> {
 public:

core/test/qa_DynamicBlock.cpp

@@ -56,7 +56,7 @@ const boost::ut::suite DynamicBlocktests = [] {
         // sources_count / 2 inputs on construction, and change the number
         // via settings
         auto &adder = testGraph.addBlock(std::make_unique<multi_adder<double>>(sources_count / 2));
-        auto &sink  = testGraph.emplaceBlock<DebugSink<double>>({});
+        auto &sink  = testGraph.emplaceBlock<InspectSink<double>>({});
 
         // Function that adds a new source node to the graph, and connects
         // it to one of adder's ports
@@ -80,7 +80,7 @@ const boost::ut::suite DynamicBlocktests = [] {
             const auto work = sink.work(1UZ);
             expect(eq(work.performed_work, 1UZ));
 
-            expect(eq(sink.lastValue, static_cast<double>((i + 1) * sources.size())));
+            expect(eq(sink.value, static_cast<double>((i + 1) * sources.size())));
         }
 
         // add yet another sources_count number of ports
@@ -104,7 +104,7 @@ const boost::ut::suite DynamicBlocktests = [] {
             const auto sink_work = sink.work(1UZ);
             expect(eq(sink_work.performed_work, 1UZ));
 
-            expect(eq(sink.lastValue, static_cast<double>((i + 1) * sources_count + (i - events_count + 1) * sources_count)));
+            expect(eq(sink.value, static_cast<double>((i + 1) * sources_count + (i - events_count + 1) * sources_count)));
         }
     };
 };