#1306 throw exception instead of silently logging it

... especially with FINE level (== DEBUG).

This pattern causes flaky failures that are very hard to debug.
If something went wrong, it's always safer to throw it with a clear description of what happened.

See "Throw early, catch late" principle.

src/main/java/net/datafaker/internal/helper/FakerIDN.java

@@ -14,14 +14,14 @@ public class FakerIDN {
     public static String toASCII(String in) {
         try {
             return IDN.toASCII(in);
-        } catch (IllegalArgumentException e) {
+        } catch (IllegalArgumentException ignore) {
             // let's continue with the character by character encoding hack.
         }
         final StringBuilder asciiResult = new StringBuilder();
         for (int i = 0; i < in.length(); i++) {
             try {
                 asciiResult.append(IDN.toASCII(in.substring(i, i + 1)));
-            } catch (Exception ignored) {
+            } catch (IllegalArgumentException ignored) {
             }
         }
         if (asciiResult.isEmpty()) {

src/main/java/net/datafaker/providers/base/Address.java

@@ -62,7 +62,7 @@ public String zipCodeByState(String stateAbbr) {
     }
 
     public String countyByZipCode(String postCode) {
-        return resolve("address.county_by_postcode." + postCode, () -> "County are not configured for postcode " + postCode);
+        return resolve("address.county_by_postcode." + postCode, () -> "County is not configured for postcode " + postCode);
     }
 
     public String streetSuffix() {

src/main/java/net/datafaker/providers/base/Image.java

@@ -158,8 +158,7 @@ private String generateBase64RasterImage(ImageType imageType, int width, int hei
             byte[] imageBytes = baos.toByteArray();
             return "data:" + imageType.mimeType + ";base64," + Base64.getEncoder().encodeToString(imageBytes);
         } catch (IOException e) {
-            e.printStackTrace();
-            return null;
+            throw new RuntimeException("Failed to generate image %s of size %sx%s".formatted(imageType, width, height), e);
         }
     }
 

src/main/java/net/datafaker/providers/base/Internet.java

@@ -246,41 +246,29 @@ public String macAddress() {
      * @return a correctly formatted IPv4 address.
      */
     public String ipV4Address() {
-        try {
-            return getIpV4Address().getHostAddress();
-        } catch (UnknownHostException e) {
-            return "127.0.0.1";
-        }
+        return getIpV4Address().getHostAddress();
     }
 
     /**
      * returns an IPv4 address.
      *
      * @return an IPv4 address.
      */
-    public InetAddress getIpV4Address() throws UnknownHostException {
-        return Inet4Address.getByAddress(new byte[]{
-            (byte) (faker.random().nextInt(254) + 2),
-            (byte) (faker.random().nextInt(254) + 2),
-            (byte) (faker.random().nextInt(254) + 2),
-            (byte) (faker.random().nextInt(254) + 2)});
+    public InetAddress getIpV4Address() {
+        return inet4Address((byte) (faker.random().nextInt(254) + 2), (byte) (faker.random().nextInt(254) + 2), (byte) (faker.random().nextInt(254) + 2), (byte) (faker.random().nextInt(254) + 2));
     }
 
     /**
      * @return a valid private IPV4 address in dot notation
      */
     public String privateIpV4Address() {
-        try {
-            return getPrivateIpV4Address().getHostAddress();
-        } catch (UnknownHostException e) {
-            return "127.0.0.1";
-        }
+        return getPrivateIpV4Address().getHostAddress();
     }
 
     /**
      * @return a private IPV4 address
      */
-    public InetAddress getPrivateIpV4Address() throws UnknownHostException {
+    public InetAddress getPrivateIpV4Address() {
         final Byte[] PRIVATE_FIRST_OCTET = {10, 127, (byte) 169, (byte) 192, (byte) 172};
         final Byte[] PRIVATE_SECOND_OCTET_172 = {16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31};
 
@@ -295,24 +283,20 @@ public InetAddress getPrivateIpV4Address() throws UnknownHostException {
             case (byte) 192 -> second = (byte) 168;
             case (byte) 169 -> second = (byte) 254;
         }
-        return Inet4Address.getByAddress(new byte[]{first, second, third, fourth});
+        return inet4Address(first, second, third, fourth);
     }
 
     /**
      * @return a valid public IPV4 address in dot notation
      */
     public String publicIpV4Address() {
-        try {
-            return getPublicIpV4Address().getHostAddress();
-        } catch (UnknownHostException e) {
-            return "127.0.0.1";
-        }
+        return getPublicIpV4Address().getHostAddress();
     }
 
     /**
      * @return a valid public IPV4 address
      */
-    public InetAddress getPublicIpV4Address() throws UnknownHostException {
+    public InetAddress getPublicIpV4Address() {
         final RandomService r = faker.random();
 
         final byte[] PRIVATE_FIRST_OCTET = {10, 127, (byte) 169, (byte) 192, (byte) 172};
@@ -325,7 +309,7 @@ public InetAddress getPublicIpV4Address() throws UnknownHostException {
         while (Arrays.binarySearch(PRIVATE_FIRST_OCTET, first) > 0) {
             first = (byte) r.nextInt(256);
         }
-        return Inet4Address.getByAddress(new byte[]{first, second, third, fourth});
+        return inet4Address(first, second, third, fourth);
     }
 
     /**
@@ -343,19 +327,15 @@ public String ipV4Cidr() {
      * @return a correctly formatted IPv6 address.
      */
     public String ipV6Address() {
-        try {
-            return getIpV6Address().getHostAddress();
-        } catch (UnknownHostException e) {
-            return "0:0:0:0:0:0:0:1";
-        }
+        return getIpV6Address().getHostAddress();
     }
 
     /**
      * <p>Returns an IPv6 address in hh:hh:hh:hh:hh:hh:hh:hh format.</p>
      *
      * @return a IPV6 address.
      */
-    public InetAddress getIpV6Address() throws UnknownHostException {
+    public InetAddress getIpV6Address() {
         final RandomService random = faker.random();
         final char[] res = new char[4 * 8 + 7];
         for (int i = 0; i < 8; i++) {
@@ -366,7 +346,7 @@ public InetAddress getIpV6Address() throws UnknownHostException {
             char[] hex = random.hex(4, false).toCharArray();
             System.arraycopy(hex, 0, res, i + offset, hex.length);
         }
-        return Inet6Address.getByName(String.valueOf(res));
+        return inet6Address(String.valueOf(res));
     }
 
     /**
@@ -550,4 +530,20 @@ public String toString() {
             return browserName;
         }
     }
+
+    private static InetAddress inet4Address(byte first, byte second, byte third, byte fourth) {
+        try {
+            return Inet4Address.getByAddress(new byte[]{first, second, third, fourth});
+        } catch (UnknownHostException e) {
+            throw new RuntimeException("Failed to create Inet4Address from %s %s %s %s".formatted(first, second, third, fourth), e);
+        }
+    }
+
+    private static InetAddress inet6Address(String host) {
+        try {
+            return Inet6Address.getByName(host);
+        } catch (UnknownHostException e) {
+            throw new RuntimeException("Failed to create Inet6Address from host '%s'".formatted(host), e);
+        }
+    }
 }

src/main/java/net/datafaker/service/FakeValues.java

@@ -13,11 +13,8 @@
 import java.util.Set;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 public class FakeValues implements FakeValuesInterface {
-    private static final Logger LOG = Logger.getLogger("faker");
     private static final Map<FakeValuesContext, FakeValues> FAKE_VALUES_MAP = new HashMap<>();
     private final FakeValuesContext fakeValuesContext;
     private volatile Map<String, Object> values;
@@ -74,9 +71,8 @@ private Map<String, Object> loadFromUrl() {
         try (InputStream stream = url.openStream()) {
             return readFromStream(stream);
         } catch (IOException e) {
-            LOG.log(Level.SEVERE, "Exception: ", e);
+            throw new RuntimeException("Failed to read fake values from %s".formatted(url), e);
         }
-        return null;
     }
 
     private Map<String, Object> loadValues() {
@@ -102,13 +98,11 @@ private Map<String, Object> loadValues() {
                     try (InputStream stream2 = getClass().getClassLoader().getResourceAsStream(path)) {
                         result = readFromStream(stream2);
                         enrichMapWithJavaNames(result);
-                    } catch (Exception e) {
-                        LOG.log(Level.SEVERE, "Exception: ", e);
                     }
                 }
 
             } catch (IOException e) {
-                LOG.log(Level.SEVERE, "Exception: ", e);
+                throw new RuntimeException("Failed to read fake values from %s".formatted(path), e);
             }
             if (result != null) {
                 return result;

src/main/java/net/datafaker/service/FakeValuesService.java

@@ -45,6 +45,8 @@
 import com.github.curiousoddman.rgxgen.RgxGen;
 
 import static java.util.Objects.requireNonNull;
+import static java.util.logging.Level.FINE;
+import static java.util.logging.Level.SEVERE;
 import static net.datafaker.transformations.Field.field;
 
 public class FakeValuesService {
@@ -947,22 +949,15 @@ private ValueResolver resolveFromMethodOn(Object obj, String directive, String[]
         if (obj == null) {
             return null;
         }
-        try {
-            final MethodAndCoercedArgs accessor = retrieveMethodAccessor(obj, directive, args);
-            return (accessor == null)
-                ? NULL_VALUE
-                : new MethodAndCoercedArgsResolver(accessor, obj);
-        } catch (Exception e) {
-            LOG.log(Level.FINE, "Can't call " + directive + " on " + obj, e);
-            return NULL_VALUE;
-        }
+        final MethodAndCoercedArgs accessor = retrieveMethodAccessor(obj, directive, args);
+        return accessor == null ? NULL_VALUE : new MethodAndCoercedArgsResolver(accessor, obj);
     }
 
     /**
      * Accepts a {@link BaseFaker} instance and a name.firstName style 'key' which is resolved to the return value of:
      * {@link BaseFaker#name()}'s {@link Name#firstName()} method.
      *
-     * @throws RuntimeException if there's a problem invoking the method or it doesn't exist.
+     * @throws RuntimeException if there's a problem invoking the method, or it doesn't exist.
      */
     private ValueResolver resolveFakerObjectAndMethod(ProviderRegistration faker, String key, int dotIndex, String[] args) {
         final String[] classAndMethod;
@@ -985,10 +980,11 @@ private ValueResolver resolveFakerObjectAndMethod(ProviderRegistration faker, St
             if (accessor == null) {
                 return NULL_VALUE;
             }
+
             return new MethodAndCoercedArgsResolver(accessor, objectWithMethodToInvoke);
-        } catch (Exception e) {
-            LOG.log(Level.SEVERE, e.getMessage(), e);
-            return NULL_VALUE;
+        } catch (InvocationTargetException | IllegalAccessException e) {
+            throw new RuntimeException("Failed to resolve faker object and method for %s (dotIndex=%s, args=%s)"
+                .formatted(key, dotIndex, Arrays.toString(args)), e);
         }
     }
 
@@ -1020,7 +1016,7 @@ private MethodAndCoercedArgs retrieveMethodAccessor(Object object, String method
      */
     private MethodAndCoercedArgs accessor(Class<?> clazz, String name, String[] args) {
         final String finalName = name;
-        LOG.log(Level.FINE, () -> "Find accessor named " + finalName + " on " + clazz.getSimpleName() + " with args " + Arrays.toString(args));
+        LOG.fine(() -> "Find accessor named " + finalName + " on " + clazz.getSimpleName() + " with args " + Arrays.toString(args));
         name = removeUnderscoreChars(name);
         final Collection<Method> methods;
         if (CLASS_2_METHODS_CACHE.containsKey(clazz)) {
@@ -1155,7 +1151,9 @@ private Object[] coerceArguments(Method accessor, String[] args) {
                 }
                 coerced[i] = coercedArgument;
             } catch (Exception e) {
-                LOG.fine("Unable to coerce " + args[i] + " to " + toType.getSimpleName() + " via " + toType.getSimpleName() + "(String) constructor.");
+                Throwable cause = unwrap(e);
+                Level level = cause instanceof IllegalArgumentException || cause instanceof NoSuchMethodException ? FINE : SEVERE;
+                LOG.log(level, "Unable to coerce " + args[i] + " to " + toType.getSimpleName() + " via " + toType.getSimpleName() + "(String) constructor.", e);
                 return null;
             }
         }
@@ -1249,10 +1247,13 @@ public Object resolve() {
         private static Object invokeAndToString(MethodAndCoercedArgs accessor, Object objectWithMethodToInvoke) {
             try {
                 return accessor.invoke(objectWithMethodToInvoke);
-            } catch (Exception e) {
-                LOG.log(Level.FINE, e.getMessage(), e);
-                return null;
+            } catch (InvocationTargetException | IllegalAccessException e) {
+                throw new RuntimeException("Failed to invoke %s on %s".formatted(accessor, objectWithMethodToInvoke), unwrap(e));
             }
         }
     }
+
+    private static Throwable unwrap(Throwable e) {
+        return e instanceof InvocationTargetException reflection ? unwrap(reflection.getTargetException()) : e;
+    }
 }

src/main/java/net/datafaker/transformations/JavaObjectTransformer.java

@@ -63,8 +63,7 @@ public Object apply(Object input, Schema<Object, ?> schema) {
                         CLASS2CONSTRUCTOR.put(clazz, primaryConstructor);
                     }
                     result = primaryConstructor.newInstance();
-                } catch (InstantiationException | IllegalAccessException |
-                         InvocationTargetException e) {
+                } catch (InstantiationException | IllegalAccessException | InvocationTargetException e) {
                     throw new RuntimeException(e);
                 }
             }

src/test/java/net/datafaker/Issue759Test.java

@@ -34,7 +34,8 @@ public static void fakeSomeData(Faker faker) {
         try {
             String county = faker.address().countyByZipCode(zipCode);
             assertThat(county).isNotEqualTo(zipCode);
-        } catch (Exception ignore) {
+        } catch (RuntimeException expected) {
+            assertThat(expected).hasMessageStartingWith("County is not configured for postcode " + zipCode);
         }
     }
 

src/test/java/net/datafaker/idnumbers/SouthKoreanIdNumberTest.java

@@ -5,7 +5,6 @@
 
 import java.time.LocalDate;
 import java.time.format.DateTimeFormatter;
-import java.time.format.DateTimeParseException;
 import java.util.Locale;
 import java.util.regex.Pattern;
 
@@ -23,12 +22,10 @@ void testValidKoKrRrn() {
 
         // Check if contains other character than digit
         assertThat(rrn).matches(D_6_D_7);
-        try {
-            // Check date
-            LocalDate.parse(rrn.substring(0, 6), YYMMDD);
-        } catch (DateTimeParseException e) {
-            assertThat(e).isNull();
-        }
+        // Check date
+        LocalDate date = LocalDate.parse(rrn.substring(0, 6), YYMMDD);
+        int currentYear = LocalDate.now().getYear();
+        assertThat(date.getYear()).isBetween(currentYear - 80, currentYear + 80);
     }
 
 }

src/test/java/net/datafaker/integration/FakerIntegrationTest.java

@@ -23,6 +23,7 @@
 import java.util.Set;
 import java.util.stream.Stream;
 
+import static java.lang.Thread.currentThread;
 import static org.apache.commons.lang3.StringUtils.substringBefore;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.reflections.ReflectionUtils.getAllMethods;
@@ -112,7 +113,8 @@ private void testAllMethodsThatReturnStringsActuallyReturnStrings(AbstractProvid
             try {
                  returnValue = method.invoke(provider);
             } catch (Exception e) {
-                throw new RuntimeException("Test for method " + method + " and object " + provider + " was failed for locale " + locale, e);
+                throw new RuntimeException("Test for method %s and object %s was failed for locale %s [thread: %s]".formatted(
+                    method, provider, locale, currentThread().getName()), e);
             }
             assertThat(returnValue).as("For method " + provider.getClass() + "#" + method.getName() + "value is '" + returnValue + "'").isInstanceOf(String.class);
             final String returnValueAsString = (String) returnValue;

src/test/java/net/datafaker/providers/base/AddressTest.java

@@ -31,7 +31,7 @@ class AddressTest extends BaseFakerTest<BaseFaker> {
     private static final Condition<String> IS_A_NUMBER = new Condition<>(s -> {
         try {
             Double.valueOf(s);
-        } catch (NumberFormatException nfe) {
+        } catch (NumberFormatException ignore) {
             return false;
         }
         return true;
@@ -184,7 +184,7 @@ void testCountyForWrongZipCode(String zipCode) {
         final BaseFaker localFaker = new BaseFaker(new Locale("en", "US"));
         assertThatThrownBy(() -> localFaker.address().countyByZipCode(zipCode))
             .isInstanceOf(RuntimeException.class)
-            .hasMessage("County are not configured for postcode " + zipCode);
+            .hasMessage("County is not configured for postcode " + zipCode);
     }
 
     @Test