BAEL-7783: Assert properties of custom exceptions with catchThrowableOfType in AssertJ (#16442)

testing-modules/assertion-libraries/src/main/java/com/baeldung/assertj/exceptions/CityNotFoundException.java

@@ -0,0 +1,22 @@
+package com.baeldung.assertj.exceptions;
+
+public class CityNotFoundException extends RuntimeException {
+
+    private String city;
+    private String message;
+
+    CityNotFoundException(String city, String message) {
+        this.city = city;
+        this.message = message;
+    }
+
+    public String getCity() {
+        return city;
+    }
+
+    @Override
+    public String getMessage() {
+        return message;
+    }
+
+}

testing-modules/assertion-libraries/src/main/java/com/baeldung/assertj/exceptions/CityUtils.java

@@ -0,0 +1,17 @@
+package com.baeldung.assertj.exceptions;
+
+import java.util.Arrays;
+import java.util.List;
+
+public final class CityUtils {
+
+    private static final List<String> CITIES = Arrays.asList("Tamassint", "London", "Madrid", "New york");
+
+    public static String search(String searchedCity) {
+        return CITIES.stream()
+            .filter(searchedCity::equals)
+            .findFirst()
+            .orElseThrow(() -> new CityNotFoundException(searchedCity, "The specified city is not found"));
+    }
+
+}