Refactor vertex_test.dart fixes #31

Author: mafinar-cmb

lib/graph/graph.dart

@@ -28,17 +28,15 @@ class Graph<T> {
 
   /// Adds an edge
   void addEdge(Vertex src, Vertex dst, [num weight = 1]) {
-    src.unlock();
-    dst.unlock();
+    unlockVertices(<Vertex>{src, dst});
     if (src.key == dst.key && !allowLoops) throw Error();
 
     src = _getOrAddVertex(src);
     dst = _getOrAddVertex(dst);
     src.addConnection(dst, weight);
 
     if (!isDigraph) dst.addConnection(src, weight);
-    src.lock();
-    dst.lock();
+    lockVertices(<Vertex>{src, dst});
   }
 
   /// Checks if vertex is included

lib/graph/vertex.dart

@@ -88,3 +88,13 @@ class Vertex<T> {
   @override
   String toString() => key;
 }
+
+/// Unlocks a set of vertices
+void unlockVertices(Set<Vertex> vertices) {
+  vertices.forEach((v) => v.unlock());
+}
+
+/// Locks a set of vertices
+void lockVertices(Set<Vertex> vertices) {
+  vertices.forEach((v) => v.lock());
+}

test/graph/vertex_test.dart

@@ -3,27 +3,42 @@ import 'package:test/test.dart';
 import 'package:algorithms/graph/vertex.dart';
 
 void main() {
-  Vertex root;
-  Vertex rootWithValue;
-  Vertex connectedVertex;
-  Vertex toBeAdded;
-  Vertex anotherVertex;
-
-  setUp(() {
+  Vertex root,
+      rootWithValue,
+      connectedVertex,
+      toBeAdded,
+      anotherVertex,
+      a,
+      b,
+      c;
+
+  void _initializeVertices() {
     root = Vertex('A');
     rootWithValue = Vertex('a', 'Wake up');
-
     connectedVertex = Vertex('0');
     toBeAdded = Vertex('1');
     anotherVertex = Vertex('2');
+    a = Vertex('a');
+    b = Vertex('b');
+    c = Vertex('c');
+  }
+
+  void _unlockVertices() {
+    unlockVertices(<Vertex>{
+      root,
+      rootWithValue,
+      connectedVertex,
+      toBeAdded,
+      anotherVertex,
+      a,
+      b,
+      c
+    });
+  }
 
-    // For test purposes, unlock all vertices
-    root.unlock();
-    rootWithValue.unlock();
-    connectedVertex.unlock();
-    toBeAdded.unlock();
-    anotherVertex.unlock();
-
+  setUp(() {
+    _initializeVertices();
+    _unlockVertices();
     connectedVertex.addConnection(toBeAdded);
     connectedVertex.addConnection(anotherVertex);
   });
@@ -36,10 +51,6 @@ void main() {
   });
 
   test('Successfully add a vertex', () {
-    var b = Vertex('B');
-    var c = Vertex('C');
-    b.unlock();
-    c.unlock();
     expect(root.addConnection(b), isTrue);
     expect(root.addConnection(c), isTrue);
     expect(root.outgoingConnections.containsKey(b), isTrue);
@@ -49,8 +60,6 @@ void main() {
   });
 
   test('Unsuccessfully add a vertex', () {
-    var b = Vertex('B');
-    b.unlock();
     root.addConnection(b);
     expect(root.addConnection(b), isFalse);
   });
@@ -62,44 +71,42 @@ void main() {
   });
 
   test('Unsuccessfully remove a vertex', () {
-    var aVertex = Vertex('-1');
-    aVertex.unlock();
-    expect(connectedVertex.removeConnection(aVertex), isFalse);
+    expect(connectedVertex.removeConnection(a), isFalse);
   });
 
   test('Trying to add to a locked vertex throws error', () {
     var locked = Vertex('PROTECTED');
-    expect(() => locked.addConnection(root), throwsA(isA<Error>()));
+    expect(() => locked.addConnection(root), throwsA(isA<UnsupportedError>()));
     root.lock();
-    expect(() => root.addConnection(root), throwsA(isA<Error>()));
+    expect(() => root.addConnection(root), throwsA(isA<UnsupportedError>()));
   });
 
   test('Trying to add a locked vertex throws error', () {
     var locked = Vertex('PROTECTED');
-    expect(() => root.addConnection(locked), throwsA(isA<Error>()));
+    expect(() => root.addConnection(locked), throwsA(isA<UnsupportedError>()));
     locked.unlock();
     root.lock();
-    expect(() => locked.addConnection(root), throwsA(isA<Error>()));
+    expect(() => locked.addConnection(root), throwsA(isA<UnsupportedError>()));
   });
 
   test('Trying to remove from a locked vertex throws error', () {
     toBeAdded.lock();
     expect(() => connectedVertex.removeConnection(toBeAdded),
-        throwsA(isA<Error>()));
+        throwsA(isA<UnsupportedError>()));
   });
 
   test('Trying to remove a locked vertex throws error', () {
     connectedVertex.lock();
     expect(() => connectedVertex.removeConnection(toBeAdded),
-        throwsA(isA<Error>()));
+        throwsA(isA<UnsupportedError>()));
   });
 
   test('Trying to remove a locked vertex throws error', () {
     var locked = Vertex('PROTECTED');
-    expect(() => root.addConnection(locked), throwsA(isA<Error>()));
+    expect(() => root.addConnection(locked), throwsA(isA<UnsupportedError>()));
     locked.unlock();
     root.lock();
-    expect(() => locked.addConnection(root), throwsA(isA<Error>()));
+    expect(() => locked.addConnection(root), throwsA(isA<UnsupportedError>()));
   });
 
   test('Check for vertex containment', () {
@@ -110,12 +117,6 @@ void main() {
   });
 
   test('Get a list of vertices', () {
-    var a = Vertex('A');
-    var b = Vertex('B');
-    var c = Vertex('C');
-    a.unlock();
-    b.unlock();
-    c.unlock();
     root.addConnection(a);
     root.addConnection(b);
     root.addConnection(c);
@@ -131,8 +132,6 @@ void main() {
   });
 
   test('Get out degree for vertex', () {
-    var c = Vertex('c');
-    c.unlock();
     expect(root.outDegree, equals(0));
     connectedVertex.addConnection(c);
     expect(connectedVertex.outDegree, equals(3));