Move main() code into tests and remove binary crate

tests/dijkstra.rs

@@ -0,0 +1,76 @@
+use grapherity::algorithms;
+use grapherity::models::Graph;
+use grapherity::models::Vertex;
+
+#[test]
+fn dijkstra() {
+    let (graph, vertices) = make_test_graph();
+    let (distances, predecessors) = algorithms::dijkstra(&graph, vertices[0]);
+    let expected_distances_from_v0 = [
+        Some(0),
+        Some(1),
+        Some(2),
+        Some(2),
+        Some(2),
+        Some(3),
+        Some(3),
+        Some(3),
+        Some(3),
+        Some(4),
+    ];
+    let expected_predecessors_from_v0 = [
+        vec![None],
+        vec![Some(vertices[0])],
+        vec![Some(vertices[1])],
+        vec![Some(vertices[1])],
+        vec![Some(vertices[1])],
+        vec![Some(vertices[2])],
+        vec![Some(vertices[2]), Some(vertices[3])],
+        vec![Some(vertices[4])],
+        vec![Some(vertices[4])],
+        vec![Some(vertices[5]), Some(vertices[6]), Some(vertices[7])],
+    ];
+    assert_eq!(
+        distances.len(),
+        graph.vertex_count(),
+        "distances count from Dijkstra's algorithm must equal vertex count"
+    );
+    assert_eq!(
+        predecessors.len(),
+        graph.vertex_count(),
+        "predecessors count from Dijkstra's algorithm must equal vertex count"
+    );
+    for i in 0..graph.vertex_count() {
+        assert_eq!(
+            distances[i], expected_distances_from_v0[i],
+            "unexpected distance from {:?} to {:?} from Dijkstra's algorithm",
+            vertices[0], vertices[i]
+        );
+        assert!(
+            expected_predecessors_from_v0[i].contains(&predecessors[i]),
+            "unexpected predecessor {:?} of {:?} from Dijkstra's algorithm",
+            predecessors[i],
+            vertices[i]
+        );
+    }
+}
+
+fn make_test_graph() -> (Graph, [Vertex; 10]) {
+    let mut graph = Graph::new();
+    let vertices: [Vertex; 10] = core::array::from_fn(|_| graph.add_vertex());
+    graph.add_edge(vertices[0], vertices[1]);
+    graph.add_edge(vertices[1], vertices[2]);
+    graph.add_edge(vertices[1], vertices[3]);
+    graph.add_edge(vertices[1], vertices[4]);
+    graph.add_edge(vertices[2], vertices[4]);
+    graph.add_edge(vertices[2], vertices[5]);
+    graph.add_edge(vertices[2], vertices[6]);
+    graph.add_edge(vertices[3], vertices[6]);
+    graph.add_edge(vertices[4], vertices[7]);
+    graph.add_edge(vertices[4], vertices[8]);
+    graph.add_edge(vertices[5], vertices[9]);
+    graph.add_edge(vertices[6], vertices[9]);
+    graph.add_edge(vertices[7], vertices[8]);
+    graph.add_edge(vertices[7], vertices[9]);
+    (graph, vertices)
+}