Convert exception assertions to AssertJ in 2 Exercises (exercism#2174)

kerolloz · web-flow · commit 76a5f6e52f25 · 2022-10-12T23:18:17.000+01:00
diff --git a/exercises/practice/change/src/test/java/ChangeCalculatorTest.java b/exercises/practice/change/src/test/java/ChangeCalculatorTest.java
@@ -1,6 +1,5 @@
-import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThrows;
 import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
@@ -98,41 +97,29 @@ public void testZeroChange() {
     public void testChangeLessThanSmallestCoinInCurrencyCannotBeRepresented() {
         ChangeCalculator changeCalculator = new ChangeCalculator(asList(5, 10));
 
-        IllegalArgumentException expected =
-            assertThrows(
-                IllegalArgumentException.class,
-                () -> changeCalculator.computeMostEfficientChange(3));
-
-        assertThat(expected)
-            .hasMessage("The total 3 cannot be represented in the given currency.");
+        assertThatExceptionOfType(IllegalArgumentException.class)
+                .isThrownBy(() -> changeCalculator.computeMostEfficientChange(3))
+                .withMessage("The total 3 cannot be represented in the given currency.");
     }
 
     @Ignore("Remove to run test")
     @Test
     public void testChangeLargerThanAllCoinsInCurrencyThatCannotBeRepresented() {
         ChangeCalculator changeCalculator = new ChangeCalculator(asList(5, 10));
 
-        IllegalArgumentException expected =
-            assertThrows(
-                IllegalArgumentException.class,
-                () -> changeCalculator.computeMostEfficientChange(94));
-
-        assertThat(expected)
-            .hasMessage("The total 94 cannot be represented in the given currency.");
+        assertThatExceptionOfType(IllegalArgumentException.class)
+                .isThrownBy(() -> changeCalculator.computeMostEfficientChange(94))
+                .withMessage("The total 94 cannot be represented in the given currency.");
     }
 
     @Ignore("Remove to run test")
     @Test
     public void testNegativeChangeIsRejected() {
         ChangeCalculator changeCalculator = new ChangeCalculator(asList(1, 2, 5));
 
-        IllegalArgumentException expected =
-            assertThrows(
-                IllegalArgumentException.class,
-                () -> changeCalculator.computeMostEfficientChange(-5));
-
-        assertThat(expected)
-            .hasMessage("Negative totals are not allowed.");
+        assertThatExceptionOfType(IllegalArgumentException.class)
+                .isThrownBy(() -> changeCalculator.computeMostEfficientChange(-5))
+                .withMessage("Negative totals are not allowed.");
     }
 
 }
diff --git a/exercises/practice/collatz-conjecture/src/test/java/CollatzCalculatorTest.java b/exercises/practice/collatz-conjecture/src/test/java/CollatzCalculatorTest.java
@@ -1,6 +1,5 @@
-import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThrows;
 
 import org.junit.Ignore;
 import org.junit.Test;
@@ -35,25 +34,17 @@ public void testAVeryLargeInput() {
     @Ignore("Remove to run test")
     @Test
     public void testZeroIsConsideredInvalidInput() {
-        IllegalArgumentException expected =
-            assertThrows(
-                IllegalArgumentException.class,
-                () -> collatzCalculator.computeStepCount(0));
-
-        assertThat(expected)
-            .hasMessage("Only natural numbers are allowed");
+        assertThatExceptionOfType(IllegalArgumentException.class)
+                .isThrownBy(() -> collatzCalculator.computeStepCount(0))
+                .withMessage("Only natural numbers are allowed");
     }
 
     @Ignore("Remove to run test")
     @Test
     public void testNegativeIntegerIsConsideredInvalidInput() {
-        IllegalArgumentException expected =
-            assertThrows(
-                IllegalArgumentException.class,
-                () -> collatzCalculator.computeStepCount(-15));
-
-        assertThat(expected)
-            .hasMessage("Only natural numbers are allowed");
+        assertThatExceptionOfType(IllegalArgumentException.class)
+                .isThrownBy(() -> collatzCalculator.computeStepCount(-15))
+                .withMessage("Only natural numbers are allowed");
     }
 
 }
