Sprint 281: DAP Hardening (steps 1933–1937)

DAPRequestValidator, DAPCapabilityNegotiator, DAPEventBroadcaster,
DAPBreakpointHitDispatcher — 26/26 tests pass.
Integration step 1937: Python+Rust DAP session round-trip verified.
Also adds allBreakpoints() to ASTNodeBreakpointMapper.
Metrics: 8 whetstone calls, 8853 tokens.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

editor/tests/step1935_test.cpp

@@ -0,0 +1,89 @@
+// Step 1935: DAPEventBroadcaster
+//
+//  t1: subscribe and broadcast fires handler
+//  t2: multiple subscribers for same event type all fire
+//  t3: unsubscribe stops handler from firing
+//  t4: broadcastAll routes by event["event"]
+//  t5: subscriberCount correct; different types independent
+
+#include "DAPEventBroadcaster.h"
+#include <iostream>
+
+namespace ws = whetstone;
+static int p=0,f=0;
+#define T(n) { std::cout<<"  "<<#n<<"... "; }
+#define P() { std::cout<<"PASS\n"; ++p; }
+#define F(m) { std::cout<<"FAIL: "<<m<<"\n"; ++f; }
+#define C(c,m) if(!(c)){F(m);return;}
+
+void t1(){
+    T(subscribe_and_broadcast_fires_handler);
+    ws::DAPEventBroadcaster b;
+    int count = 0;
+    b.subscribe("stopped", [&](const nlohmann::json&){ ++count; });
+    b.broadcast("stopped", {});
+    C(count == 1, "handler fired once");
+    b.broadcast("continued", {});
+    C(count == 1, "other event not fired");
+    P();
+}
+
+void t2(){
+    T(multiple_subscribers_all_fire);
+    ws::DAPEventBroadcaster b;
+    int a = 0, c = 0;
+    b.subscribe("output", [&](const nlohmann::json&){ ++a; });
+    b.subscribe("output", [&](const nlohmann::json&){ ++c; });
+    b.broadcast("output", {});
+    C(a == 1 && c == 1, "both handlers fired");
+    P();
+}
+
+void t3(){
+    T(unsubscribe_stops_handler);
+    ws::DAPEventBroadcaster b;
+    int count = 0;
+    int id = b.subscribe("stopped", [&](const nlohmann::json&){ ++count; });
+    b.broadcast("stopped", {});
+    C(count == 1, "fired before unsubscribe");
+    b.unsubscribe(id);
+    b.broadcast("stopped", {});
+    C(count == 1, "not fired after unsubscribe");
+    C(b.subscriberCount("stopped") == 0, "count 0 after unsubscribe");
+    P();
+}
+
+void t4(){
+    T(broadcastAll_routes_by_event_field);
+    ws::DAPEventBroadcaster b;
+    int stopped = 0, output = 0;
+    b.subscribe("stopped", [&](const nlohmann::json&){ ++stopped; });
+    b.subscribe("output",  [&](const nlohmann::json&){ ++output;  });
+    nlohmann::json ev = {{"type","event"},{"seq",1},{"event","stopped"},{"body",{}}};
+    b.broadcastAll(ev);
+    C(stopped == 1, "stopped handler fired");
+    C(output  == 0, "output handler not fired");
+    // no event field → no-op
+    b.broadcastAll({{"type","event"},{"seq",2}});
+    C(stopped == 1, "still 1 after no-event broadcast");
+    P();
+}
+
+void t5(){
+    T(subscriberCount_independent_per_type);
+    ws::DAPEventBroadcaster b;
+    b.subscribe("stopped",  [](const nlohmann::json&){});
+    b.subscribe("stopped",  [](const nlohmann::json&){});
+    b.subscribe("continued",[](const nlohmann::json&){});
+    C(b.subscriberCount("stopped")   == 2, "two stopped");
+    C(b.subscriberCount("continued") == 1, "one continued");
+    C(b.subscriberCount("output")    == 0, "zero output");
+    P();
+}
+
+int main(){
+    std::cout << "Step 1935: DAPEventBroadcaster\n";
+    t1(); t2(); t3(); t4(); t5();
+    std::cout << "\n" << p << "/" << (p+f) << " passed\n";
+    return f > 0 ? 1 : 0;
+}