Refactor exception assertions

Author: ref-humbold

src/test/java/algolib/TestUtils.java

@@ -0,0 +1,45 @@
+package algolib;
+
+import org.assertj.core.api.Assertions;
+
+public final class TestUtils
+{
+    public static <T> T failOnException(ExceptionalSupplier<T> supplier)
+    {
+        try
+        {
+            return supplier.get();
+        }
+        catch(Exception e)
+        {
+            Assertions.fail("Unexpected exception %s".formatted(e.getClass().getSimpleName()));
+            return null;
+        }
+    }
+
+    public static void failOnException(ExceptionalRunnable supplier)
+    {
+        try
+        {
+            supplier.run();
+        }
+        catch(Exception e)
+        {
+            Assertions.fail("Unexpected exception %s".formatted(e.getClass().getSimpleName()));
+        }
+    }
+
+    @FunctionalInterface
+    public interface ExceptionalSupplier<T>
+    {
+        T get()
+                throws Exception;
+    }
+
+    @FunctionalInterface
+    public interface ExceptionalRunnable
+    {
+        void run()
+                throws Exception;
+    }
+}

src/test/java/algolib/geometry/dim2/ClosestPointsTest.java

@@ -13,11 +13,9 @@ public class ClosestPointsTest
     @Test
     public void findClosestPoints_WhenNoPoints_ThenNoSuchElementException()
     {
-        // when
-        Throwable throwable =
-                Assertions.catchThrowable(() -> ClosestPoints.findClosestPoints(List.of()));
-        // then
-        Assertions.assertThat(throwable).isInstanceOf(NoSuchElementException.class);
+
+        Assertions.assertThatThrownBy(() -> ClosestPoints.findClosestPoints(List.of()))
+                  .isInstanceOf(NoSuchElementException.class);
     }
 
     @Test

src/test/java/algolib/geometry/dim2/Vector2DTest.java

@@ -131,9 +131,7 @@ public void divide_ThenDivideEachCoordinate()
     @Test
     public void divide_WhenDivisionByZero_ThenArithmeticException()
     {
-        // when
-        Throwable throwable = Assertions.catchThrowable(() -> Vector2D.of(1.0, 1.0).divide(0));
-        // then
-        Assertions.assertThat(throwable).isInstanceOf(ArithmeticException.class);
+        Assertions.assertThatThrownBy(() -> Vector2D.of(1.0, 1.0).divide(0))
+                  .isInstanceOf(ArithmeticException.class);
     }
 }

src/test/java/algolib/geometry/dim3/Vector3DTest.java

@@ -180,10 +180,7 @@ public void divide_ThenDivideEachCoordinate()
     @Test
     public void divide_WhenDivisionByZero_ThenArithmeticException()
     {
-        // when
-        Throwable throwable = Assertions.catchThrowable(() -> Vector3D.of(1.0, 1.0, 1.0).divide(0));
-
-        // then
-        Assertions.assertThat(throwable).isInstanceOf(ArithmeticException.class);
+        Assertions.assertThatThrownBy(() -> Vector3D.of(1.0, 1.0, 1.0).divide(0))
+                  .isInstanceOf(ArithmeticException.class);
     }
 }

src/test/java/algolib/graphs/DirectedSimpleGraphTest.java

@@ -60,17 +60,13 @@ public void getProperties_get_WhenNotExisting_ThenIllegalArgumentException()
         Vertex<Integer> vertex = new Vertex<>(14);
         Edge<Integer> edge1 = new Edge<>(new Vertex<>(2), new Vertex<>(8));
         Edge<Integer> edge2 = new Edge<>(new Vertex<>(0), new Vertex<>(-1));
-        // when
-        Throwable throwableVertex =
-                Assertions.catchThrowable(() -> testObject.getProperties().get(vertex));
-        Throwable throwableEdge1 =
-                Assertions.catchThrowable(() -> testObject.getProperties().get(edge1));
-        Throwable throwableEdge2 =
-                Assertions.catchThrowable(() -> testObject.getProperties().get(edge2));
         // then
-        Assertions.assertThat(throwableVertex).isInstanceOf(IllegalArgumentException.class);
-        Assertions.assertThat(throwableEdge1).isInstanceOf(IllegalArgumentException.class);
-        Assertions.assertThat(throwableEdge2).isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.getProperties().get(vertex))
+                  .isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.getProperties().get(edge1))
+                  .isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.getProperties().get(edge2))
+                  .isInstanceOf(IllegalArgumentException.class);
     }
 
     @Test
@@ -295,11 +291,9 @@ public void addVertex_WhenExistingVertex_ThenNull()
         String property = "qwerty";
 
         testObject.getProperties().set(vertex, property);
-        // when
-        Throwable throwable =
-                Assertions.catchThrowable(() -> testObject.addVertex(vertex, "abcdefg"));
         // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.addVertex(vertex, "abcdefg"))
+                  .isInstanceOf(IllegalArgumentException.class);
         Assertions.assertThat(testObject.getVerticesCount()).isEqualTo(10);
         Assertions.assertThat(testObject.getProperties().get(vertex)).isEqualTo(property);
     }
@@ -330,11 +324,9 @@ public void addEdgeBetween_WhenExistingEdge_ThenIllegalArgumentException()
         Vertex<Integer> source = new Vertex<>(3);
         Vertex<Integer> destination = new Vertex<>(7);
         testObject.addEdgeBetween(source, destination);
-        // when
-        Throwable throwable =
-                Assertions.catchThrowable(() -> testObject.addEdgeBetween(source, destination));
         // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.addEdgeBetween(source, destination))
+                  .isInstanceOf(IllegalArgumentException.class);
     }
 
     @Test

src/test/java/algolib/graphs/MultipartiteGraphTest.java

@@ -164,10 +164,8 @@ public void getVerticesFromGroup_WhenValidGroup_ThenVertices()
     @Test
     public void getVerticesFromGroup_WhenInvalidGroup_ThenIndexOutOfBoundsException()
     {
-        // when
-        Throwable throwable = Assertions.catchThrowable(() -> testObject.getVerticesFromGroup(14));
-        // then
-        Assertions.assertThat(throwable).isInstanceOf(IndexOutOfBoundsException.class);
+        Assertions.assertThatThrownBy(() -> testObject.getVerticesFromGroup(14))
+                  .isInstanceOf(IndexOutOfBoundsException.class);
     }
 
     @Test
@@ -193,22 +191,18 @@ public void addVertex_WhenExistingVertex_ThenIllegalArgumentException()
         String property = "qwerty";
 
         testObject.getProperties().set(vertex, property);
-        // when
-        Throwable throwable =
-                Assertions.catchThrowable(() -> testObject.addVertex(3, vertex, "xyz"));
-        // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalArgumentException.class);
+
+        Assertions.assertThatThrownBy(() -> testObject.addVertex(3, vertex, "xyz"))
+                  .isInstanceOf(IllegalArgumentException.class);
         Assertions.assertThat(testObject.getVerticesCount()).isEqualTo(10);
         Assertions.assertThat(testObject.getProperties().get(vertex)).isEqualTo(property);
     }
 
     @Test
     public void addVertex_WhenInvalidGroup_ThenIndexOutOfBoundsException()
     {
-        // when
-        Throwable throwable = Assertions.catchThrowable(() -> testObject.addVertex(-3, 19));
-        // then
-        Assertions.assertThat(throwable).isInstanceOf(IndexOutOfBoundsException.class);
+        Assertions.assertThatThrownBy(() -> testObject.addVertex(-3, 19))
+                  .isInstanceOf(IndexOutOfBoundsException.class);
     }
 
     @Test
@@ -235,30 +229,24 @@ public void addEdgeBetween_WhenExistingEdge_ThenIllegalArgumentException()
         Vertex<Integer> destination = new Vertex<>(3);
 
         testObject.addEdgeBetween(source, destination);
-        // when
-        Throwable throwable =
-                Assertions.catchThrowable(() -> testObject.addEdgeBetween(source, destination));
-        // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalArgumentException.class);
+
+        Assertions.assertThatThrownBy(() -> testObject.addEdgeBetween(source, destination))
+                  .isInstanceOf(IllegalArgumentException.class);
     }
 
     @Test
     public void addEdgeBetween_WhenSameGroup_ThenGraphPartitionException()
     {
-        // when
-        Throwable throwable = Assertions.catchThrowable(
-                () -> testObject.addEdgeBetween(new Vertex<>(5), new Vertex<>(8)));
-        // then
-        Assertions.assertThat(throwable).isInstanceOf(GraphPartitionException.class);
+        Assertions.assertThatThrownBy(
+                          () -> testObject.addEdgeBetween(new Vertex<>(5), new Vertex<>(8)))
+                  .isInstanceOf(GraphPartitionException.class);
     }
 
     @Test
     public void addEdgeBetween_WhenInvalidVertex_ThenIllegalArgumentException()
     {
-        // when
-        Throwable throwable = Assertions.catchThrowable(
-                () -> testObject.addEdgeBetween(new Vertex<>(15), new Vertex<>(18)));
-        // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(
+                          () -> testObject.addEdgeBetween(new Vertex<>(15), new Vertex<>(18)))
+                  .isInstanceOf(IllegalArgumentException.class);
     }
 }

src/test/java/algolib/graphs/TreeGraphTest.java

@@ -183,11 +183,10 @@ public void addVertex_WhenExistingVertex_ThenIllegalArgumentException()
         String property = "qwerty";
 
         testObject.getProperties().set(vertex, property);
-        // when
-        Throwable throwable = Assertions.catchThrowable(
-                () -> testObject.addVertex(vertex, new Vertex<>(2), "abcdefg", "xyz"));
         // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(
+                          () -> testObject.addVertex(vertex, new Vertex<>(2), "abcdefg", "xyz"))
+                  .isInstanceOf(IllegalArgumentException.class);
         Assertions.assertThat(testObject.getVerticesCount()).isEqualTo(8);
         Assertions.assertThat(testObject.getProperties().get(vertex)).isEqualTo(property);
     }

src/test/java/algolib/graphs/UndirectedSimpleGraphTest.java

@@ -59,17 +59,13 @@ public void getProperties_get_WhenNotExisting_ThenIllegalArgumentException()
         Vertex<Integer> vertex = new Vertex<>(14);
         Edge<Integer> edge1 = new Edge<>(new Vertex<>(2), new Vertex<>(8));
         Edge<Integer> edge2 = new Edge<>(new Vertex<>(0), new Vertex<>(-1));
-        // when
-        Throwable throwableVertex =
-                Assertions.catchThrowable(() -> testObject.getProperties().get(vertex));
-        Throwable throwableEdge1 =
-                Assertions.catchThrowable(() -> testObject.getProperties().get(edge1));
-        Throwable throwableEdge2 =
-                Assertions.catchThrowable(() -> testObject.getProperties().get(edge2));
         // then
-        Assertions.assertThat(throwableVertex).isInstanceOf(IllegalArgumentException.class);
-        Assertions.assertThat(throwableEdge1).isInstanceOf(IllegalArgumentException.class);
-        Assertions.assertThat(throwableEdge2).isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.getProperties().get(vertex))
+                  .isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.getProperties().get(edge1))
+                  .isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.getProperties().get(edge2))
+                  .isInstanceOf(IllegalArgumentException.class);
     }
 
     @Test
@@ -294,11 +290,9 @@ public void addVertex_WhenExistingVertex_ThenNull()
         String property = "qwerty";
 
         testObject.getProperties().set(vertex, property);
-        // when
-        Throwable throwable =
-                Assertions.catchThrowable(() -> testObject.addVertex(vertex, "abcdefg"));
         // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.addVertex(vertex, "abcdefg"))
+                  .isInstanceOf(IllegalArgumentException.class);
         Assertions.assertThat(testObject.getVerticesCount()).isEqualTo(10);
         Assertions.assertThat(testObject.getProperties().get(vertex)).isEqualTo(property);
     }
@@ -330,11 +324,9 @@ public void addEdgeBetween_WhenExistingEdge_ThenIllegalArgumentException()
         Vertex<Integer> destination = new Vertex<>(7);
 
         testObject.addEdgeBetween(source, destination);
-        // when
-        Throwable throwable =
-                Assertions.catchThrowable(() -> testObject.addEdgeBetween(source, destination));
         // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.addEdgeBetween(source, destination))
+                  .isInstanceOf(IllegalArgumentException.class);
     }
 
     @Test
@@ -345,11 +337,9 @@ public void addEdgeBetween_WhenReversedEdge_ThenIllegalArgumentException()
         Vertex<Integer> destination = new Vertex<>(7);
 
         testObject.addEdgeBetween(source, destination);
-        // when
-        Throwable throwable =
-                Assertions.catchThrowable(() -> testObject.addEdgeBetween(destination, source));
         // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalArgumentException.class);
+        Assertions.assertThatThrownBy(() -> testObject.addEdgeBetween(destination, source))
+                  .isInstanceOf(IllegalArgumentException.class);
     }
 
     @Test

src/test/java/algolib/graphs/algorithms/ShortestPathsTest.java

@@ -140,11 +140,11 @@ public void bellmanFord_WhenNegativeCycle_ThenIllegalStateException()
         // given
         directedGraph.addEdgeBetween(directedGraph.getVertex(8), directedGraph.getVertex(3),
                                      new Weight(-20.0));
-        // when
-        Throwable throwable = Assertions.catchThrowable(
-                () -> ShortestPaths.bellmanFord(directedGraph, directedGraph.getVertex(1)));
         // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalStateException.class);
+        Assertions.assertThatThrownBy(
+                          () -> ShortestPaths.bellmanFord(directedGraph,
+                                                          directedGraph.getVertex(1)))
+                  .isInstanceOf(IllegalStateException.class);
     }
 
     // endregion
@@ -182,11 +182,10 @@ public void dijkstra_WhenNegativeEdge_ThenIllegalStateException()
         // given
         directedGraph.addEdgeBetween(directedGraph.getVertex(8), directedGraph.getVertex(3),
                                      new Weight(-5.0));
-        // when
-        Throwable throwable = Assertions.catchThrowable(
-                () -> ShortestPaths.dijkstra(directedGraph, directedGraph.getVertex(1)));
         // then
-        Assertions.assertThat(throwable).isInstanceOf(IllegalStateException.class);
+        Assertions.assertThatThrownBy(
+                          () -> ShortestPaths.dijkstra(directedGraph, directedGraph.getVertex(1)))
+                  .isInstanceOf(IllegalStateException.class);
     }
 
     // endregion

src/test/java/algolib/graphs/algorithms/TopologicalSortingTest.java

@@ -58,11 +58,9 @@ public void inputsTopologicalSort_WhenCyclicGraph_ThenDirectedCyclicGraphExcepti
         graph.addEdgeBetween(graph.getVertex(5), graph.getVertex(1));
         graph.addEdgeBetween(graph.getVertex(5), graph.getVertex(2));
         graph.addEdgeBetween(graph.getVertex(5), graph.getVertex(4));
-        // when
-        Throwable throwable =
-                Assertions.catchThrowable(() -> TopologicalSorting.inputsTopologicalSort(graph));
         // then
-        Assertions.assertThat(throwable).isInstanceOf(DirectedCyclicGraphException.class);
+        Assertions.assertThatThrownBy(() -> TopologicalSorting.inputsTopologicalSort(graph))
+                  .isInstanceOf(DirectedCyclicGraphException.class);
     }
 
     @Test
@@ -129,11 +127,9 @@ public void dfsTopologicalSort_WhenCyclicGraph_ThenDirectedCyclicGraphException(
         graph.addEdgeBetween(graph.getVertex(5), graph.getVertex(1));
         graph.addEdgeBetween(graph.getVertex(5), graph.getVertex(2));
         graph.addEdgeBetween(graph.getVertex(5), graph.getVertex(4));
-        // when
-        Throwable throwable =
-                Assertions.catchThrowable(() -> TopologicalSorting.dfsTopologicalSort(graph));
         // then
-        Assertions.assertThat(throwable).isInstanceOf(DirectedCyclicGraphException.class);
+        Assertions.assertThatThrownBy(() -> TopologicalSorting.dfsTopologicalSort(graph))
+                  .isInstanceOf(DirectedCyclicGraphException.class);
     }
 
     @Test