first set of changes

src/doctest/csf/Digraph.cpp

@@ -0,0 +1,73 @@
+#include <test/csf/Digraph.h>
+
+#include <doctest/doctest.h>
+
+#include <sstream>
+#include <string>
+#include <vector>
+
+using namespace xrpl::test::csf;
+
+TEST_SUITE_BEGIN("Digraph");
+
+TEST_CASE("Digraph basic operations")
+{
+    using Graph = Digraph<char, std::string>;
+    Graph graph;
+
+    CHECK(!graph.connected('a', 'b'));
+    CHECK(!graph.edge('a', 'b'));
+    CHECK(!graph.disconnect('a', 'b'));
+
+    CHECK(graph.connect('a', 'b', "foobar"));
+    CHECK(graph.connected('a', 'b'));
+    CHECK(*graph.edge('a', 'b') == "foobar");
+
+    CHECK(!graph.connect('a', 'b', "repeat"));
+    CHECK(graph.disconnect('a', 'b'));
+    CHECK(graph.connect('a', 'b', "repeat"));
+    CHECK(graph.connected('a', 'b'));
+    CHECK(*graph.edge('a', 'b') == "repeat");
+
+    CHECK(graph.connect('a', 'c', "tree"));
+
+    {
+        std::vector<std::tuple<char, char, std::string>> edges;
+
+        for (auto const& edge : graph.outEdges('a'))
+        {
+            edges.emplace_back(edge.source, edge.target, edge.data);
+        }
+
+        std::vector<std::tuple<char, char, std::string>> expected;
+        expected.emplace_back('a', 'b', "repeat");
+        expected.emplace_back('a', 'c', "tree");
+        CHECK(edges == expected);
+        CHECK(graph.outDegree('a') == expected.size());
+    }
+
+    CHECK(graph.outEdges('r').size() == 0);
+    CHECK(graph.outDegree('r') == 0);
+    CHECK(graph.outDegree('c') == 0);
+
+    // only 'a' has out edges
+    CHECK(graph.outVertices().size() == 1);
+    std::vector<char> expected = {'b', 'c'};
+
+    CHECK((graph.outVertices('a') == expected));
+    CHECK(graph.outVertices('b').size() == 0);
+    CHECK(graph.outVertices('c').size() == 0);
+    CHECK(graph.outVertices('r').size() == 0);
+
+    std::stringstream ss;
+    graph.saveDot(ss, [](char v) { return v; });
+    std::string expectedDot =
+        "digraph {\n"
+        "a -> b;\n"
+        "a -> c;\n"
+        "}\n";
+    CHECK(ss.str() == expectedDot);
+}
+
+TEST_SUITE_END();
+