Adding check for non-existent dagid

daggy/src/loggers/dag_run/OStreamLogger.cpp

@@ -111,6 +111,9 @@ namespace daggy {
             }
 
             DAGRunRecord OStreamLogger::getDAGRun(DAGRunID dagRunID) {
+                if (dagRunID >= dagRuns_.size()) {
+                    throw std::runtime_error("No such DAGRun ID");
+                }
                 std::lock_guard<std::mutex> lock(guard_);
                 return dagRuns_[dagRunID];
             }

tests/unit_server.cpp

@@ -71,6 +71,11 @@ TEST_CASE("rest_endpoint", "[server_basic]") {
         REQUIRE(response.code() == Pistache::Http::Code::Ok);
     }
 
+    SECTION ("Querying a non-existent dagrunid should fail ") {
+        auto response = REQUEST(baseURL + "/v1/dagrun/100");
+        REQUIRE(response.code() != Pistache::Http::Code::Ok);
+    }
+
     SECTION("Simple DAGRun Submission") {
         std::string dagRun = R"({
             "name": "unit_server",