Football Match Reports: Teach default keyword instead of exceptions

exercises/concept/football-match-reports/.docs/instructions.md

@@ -27,11 +27,11 @@ FootballMatchReports.onField(10);
 // => "striker"
 ```
 
-## 2. Raise an alert if an unknown shirt number is encountered
+## 2. Output "unknown" if the shirt number is not part of the official list
 
-Modify the `FootballMatchReports.onField()` method to throw an `IllegalArgumentException` when a shirt number outside the range 1-11 is processed.
+Modify the `FootballMatchReports.onField()` method to return 'unknown' when a shirt number outside the range 1-11 is processed.
 
 ```java
 FootballMatchReports.onField(13);
-// => Throw IllegalArgumentException
+// => "unknown"
 ```

exercises/concept/football-match-reports/src/test/java/FootballMatchReportsTest.java

@@ -3,7 +3,6 @@
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
 public class FootballMatchReportsTest {
 
@@ -68,17 +67,15 @@ public void test_right_wing() {
 
     @Test
     @Tag("task:2")
-    @DisplayName("The onField method throws IllegalArgumentException for unknown shirt number")
+    @DisplayName("The onField method returns 'unknown' for unknown shirt number")
     public void test_exception() {
-        assertThatExceptionOfType(IllegalArgumentException.class)
-                .isThrownBy(() -> FootballMatchReports.onField(13));
+        assertThat(FootballMatchReports.onField(13)).isEqualTo("unknown");
     }
 
     @Test
     @Tag("task:2")
-    @DisplayName("The onField method throws IllegalArgumentException for negative shirt number")
+    @DisplayName("The onField method returns 'unknown' for negative shirt number")
     public void test_exception_negative_number() {
-        assertThatExceptionOfType(IllegalArgumentException.class)
-                .isThrownBy(() -> FootballMatchReports.onField(-1));
+        assertThat(FootballMatchReports.onField(-1)).isEqualTo("unknown");
     }
 }