Rewrite ThingParser usages.

This commit changes how the ThingParser is used throughout the code base. Instead of blindly filtering out null values, we're now throwing a new InvalidThingInputString exception. This exception is caught in an outer scope that has more context. The exception is then unwrapped and rethrown as a ConfigError with the additional context. In the outermost scope of (re)loading the config-file, the ConfigError is caught and printed, and then (re)loading stops gracefully.

We still need a proper way to handle loads/reloads consistently to get rid of the default command usage message, but this is a good step towards better usability in the face of user errors.

Fixes #478

changelog.md

@@ -15,6 +15,7 @@ These changes will (most likely) be included in the next version.
 - The new per-arena setting `join-interrupt-timer` makes it possible to add a "delay" to the join and spec commands. If the player moves or takes damage during this delay, the command is interrupted. This should help prevent exploits on PvP servers.
 - Right-clicking is now allowed in the lobby. This makes it possible to activate blocks like buttons and levers.
 - Snow and ice no longer melts in arenas.
+- Much of the parsing logic has been rewritten so that MobArena now logs more user-friendly errors when it encounters invalid values in the config-file.
 
 Thanks to:
 - PrinceIonia and Nesseley for help with test of dev builds

src/main/java/com/garbagemule/MobArena/ArenaImpl.java

@@ -20,6 +20,7 @@ import com.garbagemule.MobArena.region.ArenaRegion;
 import com.garbagemule.MobArena.repairable.Repairable;
 import com.garbagemule.MobArena.repairable.RepairableComparator;
 import com.garbagemule.MobArena.repairable.RepairableContainer;
+import com.garbagemule.MobArena.things.InvalidThingInputString;
 import com.garbagemule.MobArena.things.Thing;
 import com.garbagemule.MobArena.util.ClassChests;
 import com.garbagemule.MobArena.util.inventory.InventoryManager;
@@ -205,13 +206,9 @@ public class ArenaImpl implements Arena
             for (String fee : feeString.split(",")) {
                 try {
                     Thing thing = plugin.getThingManager().parse(fee.trim());
-                    if (thing == null) {
+                    this.entryFee.add(thing);
-                        plugin.getLogger().warning("Failed to parse entry fee: " + fee.trim());
+                } catch (InvalidThingInputString e) {
-                    } else {
+                    throw new ConfigError("Failed to parse entry fee of arena " + name + ": " + e.getInput());
-                        this.entryFee.add(thing);
-                    }
-                } catch (Exception e) {
-                    plugin.getLogger().severe("Exception parsing entry fee '" + fee.trim() + "': " + e.getLocalizedMessage());
                 }
             }
         }

src/main/java/com/garbagemule/MobArena/ArenaMasterImpl.java

@@ -5,6 +5,7 @@ import static com.garbagemule.MobArena.util.config.ConfigUtils.parseLocation;
 
 import com.garbagemule.MobArena.framework.Arena;
 import com.garbagemule.MobArena.framework.ArenaMaster;
+import com.garbagemule.MobArena.things.InvalidThingInputString;
 import com.garbagemule.MobArena.things.Thing;
 import com.garbagemule.MobArena.util.JoinInterruptTimer;
 import com.garbagemule.MobArena.util.config.ConfigUtils;
@@ -340,9 +341,8 @@ public class ArenaMasterImpl implements ArenaMaster
         if (priceString != null) {
             try {
                 price = plugin.getThingManager().parse(priceString);
-            } catch (Exception e) {
+            } catch (InvalidThingInputString e) {
-                plugin.getLogger().warning("Exception parsing class price: " + e.getLocalizedMessage());
+                throw new ConfigError("Failed to parse price of class " + classname + ": " + e.getInput());
-                price = null;
             }
         }
 
@@ -380,13 +380,15 @@ public class ArenaMasterImpl implements ArenaMaster
             items = Arrays.asList(value.split(","));
         }
 
-        List<Thing> things = items.stream()
+        try {
-            .map(String::trim)
+            List<Thing> things = items.stream()
-            .map(plugin.getThingManager()::parse)
+                .map(String::trim)
-            .filter(Objects::nonNull)
+                .map(plugin.getThingManager()::parse)
-            .collect(Collectors.toList());
+                .collect(Collectors.toList());
-
+            arenaClass.setItems(things);
-        arenaClass.setItems(things);
+        } catch (InvalidThingInputString e) {
+            throw new ConfigError("Failed to parse item for class " + arenaClass.getConfigName() + ": " + e.getInput());
+        }
     }
 
     private void loadClassArmor(ConfigurationSection section, ArenaClass arenaClass) {
@@ -394,76 +396,91 @@ public class ArenaMasterImpl implements ArenaMaster
         loadClassArmorLegacyNode(section, arenaClass);
 
         // Specific armor pieces
-        loadClassArmorPiece(section, "helmet",     arenaClass::setHelmet);
+        String name = arenaClass.getConfigName();
-        loadClassArmorPiece(section, "chestplate", arenaClass::setChestplate);
+        loadClassArmorPiece(section, "helmet",     name, arenaClass::setHelmet);
-        loadClassArmorPiece(section, "leggings",   arenaClass::setLeggings);
+        loadClassArmorPiece(section, "chestplate", name, arenaClass::setChestplate);
-        loadClassArmorPiece(section, "boots",      arenaClass::setBoots);
+        loadClassArmorPiece(section, "leggings",   name, arenaClass::setLeggings);
-        loadClassArmorPiece(section, "offhand",    arenaClass::setOffHand);
+        loadClassArmorPiece(section, "boots",      name, arenaClass::setBoots);
+        loadClassArmorPiece(section, "offhand",    name, arenaClass::setOffHand);
     }
 
     private void loadClassArmorLegacyNode(ConfigurationSection section, ArenaClass arenaClass) {
         List<String> armor = section.getStringList("armor");
         if (armor == null || armor.isEmpty()) {
-            String value = section.getString("armor", "");
+            String value = section.getString("armor", null);
+            if (value == null || value.isEmpty()) {
+                return;
+            }
             armor = Arrays.asList(value.split(","));
         }
 
-        // Prepend "armor:" for the armor thing parser
+        try {
-        List<Thing> things = armor.stream()
+            // Prepend "armor:" for the armor thing parser
-            .map(String::trim)
+            List<Thing> things = armor.stream()
-            .map(s -> "armor:" + s)
+                .map(String::trim)
-            .map(plugin.getThingManager()::parse)
+                .map(s -> plugin.getThingManager().parse("armor", s))
-            .filter(Objects::nonNull)
+                .collect(Collectors.toList());
-            .collect(Collectors.toList());
+            arenaClass.setArmor(things);
-
+        } catch (InvalidThingInputString e) {
-        arenaClass.setArmor(things);
+            throw new ConfigError("Failed to parse armor for class " + arenaClass.getConfigName() + ": " + e.getInput());
+        }
     }
 
-    private void loadClassArmorPiece(ConfigurationSection section, String slot, Consumer<Thing> setter) {
+    private void loadClassArmorPiece(ConfigurationSection section, String slot, String name, Consumer<Thing> setter) {
         String value = section.getString(slot, null);
         if (value == null) {
             return;
         }
-        // Prepend the slot name for the item parser
+        try {
-        Thing thing =  plugin.getThingManager().parse(slot + ":" + value);
+            // Prepend the slot name for the item parser
-        if (thing == null) {
+            Thing thing = plugin.getThingManager().parse(slot, value);
-            return;
+            setter.accept(thing);
+        } catch (InvalidThingInputString e) {
+            throw new ConfigError("Failed to parse " + slot + " slot for class " + name + ": " + e.getInput());
         }
-        setter.accept(thing);
     }
 
     private void loadClassPotionEffects(ConfigurationSection section, ArenaClass arenaClass) {
         List<String> effects = section.getStringList("effects");
         if (effects == null || effects.isEmpty()) {
-            String value = section.getString("effects", "");
+            String value = section.getString("effects", null);
+            if (value == null || value.isEmpty()) {
+                return;
+            }
             effects = Arrays.asList(value.split(","));
         }
 
-        // Prepend "effect:" for the potion effect thing parser
+        try {
-        List<Thing> things = effects.stream()
+            // Prepend "effect:" for the potion effect thing parser
-            .map(String::trim)
+            List<Thing> things = effects.stream()
-            .map(s -> "effect:" + s)
+                .map(String::trim)
-            .map(plugin.getThingManager()::parse)
+                .map(s -> plugin.getThingManager().parse("effect", s))
-            .filter(Objects::nonNull)
+                .collect(Collectors.toList());
-            .collect(Collectors.toList());
 
-        arenaClass.setEffects(things);
+            arenaClass.setEffects(things);
+        } catch (InvalidThingInputString e) {
+            throw new ConfigError("Failed to parse potion effect of class " + arenaClass.getConfigName() + ": " + e.getInput());
+        }
     }
 
     private void loadClassPermissions(ArenaClass arenaClass, ConfigurationSection section) {
-        section.getStringList("permissions").stream()
+        try {
-            .map(perm -> "perm:" + perm)
+            section.getStringList("permissions").stream()
-            .map(plugin.getThingManager()::parse)
+                .map(s -> plugin.getThingManager().parse("perm", s))
-            .filter(Objects::nonNull)
+                .forEach(arenaClass::addPermission);
-            .forEach(arenaClass::addPermission);
+        } catch (InvalidThingInputString e) {
+            throw new ConfigError("Failed to parse permission of class " + arenaClass.getConfigName() + ": " + e.getInput());
+        }
     }
 
     private void loadClassLobbyPermissions(ArenaClass arenaClass, ConfigurationSection section) {
-        section.getStringList("lobby-permissions").stream()
+        try {
-            .map(perm -> "perm:" + perm)
+            section.getStringList("lobby-permissions").stream()
-            .map(plugin.getThingManager()::parse)
+                .map(s -> plugin.getThingManager().parse("perm", s))
-            .filter(Objects::nonNull)
+                .forEach(arenaClass::addLobbyPermission);
-            .forEach(arenaClass::addLobbyPermission);
+        } catch (InvalidThingInputString e) {
+            throw new ConfigError("Failed to parse lobby-permission of class " + arenaClass.getConfigName() + ": " + e.getInput());
+        }
     }
 
     /**

src/main/java/com/garbagemule/MobArena/ConfigError.java

@@ -0,0 +1,7 @@
+package com.garbagemule.MobArena;
+
+public class ConfigError extends RuntimeException {
+    public ConfigError(String message) {
+        super(message);
+    }
+}

src/main/java/com/garbagemule/MobArena/MAUtils.java

@@ -3,6 +3,7 @@ package com.garbagemule.MobArena;
 import com.garbagemule.MobArena.framework.Arena;
 import com.garbagemule.MobArena.framework.ArenaMaster;
 import com.garbagemule.MobArena.region.ArenaRegion;
+import com.garbagemule.MobArena.things.InvalidThingInputString;
 import com.garbagemule.MobArena.things.Thing;
 import com.garbagemule.MobArena.util.ItemParser;
 import com.garbagemule.MobArena.util.TextUtils;
@@ -66,13 +67,9 @@ public class MAUtils
             for (String reward : rewards.split(",")) {
                 try {
                     Thing thing = plugin.getThingManager().parse(reward.trim());
-                    if (thing == null) {
+                    things.add(thing);
-                        plugin.getLogger().warning("Failed to parse reward: " + reward.trim());
+                } catch (InvalidThingInputString e) {
-                    } else {
+                    throw new ConfigError("Failed to parse reward for wave " + wave + " in the '" + type + "' branch of arena " + arena + ": " + e.getInput());
-                        things.add(thing);
-                    }
-                } catch (Exception e) {
-                    plugin.getLogger().severe("Exception parsing reward '" + reward.trim() + "': " + e.getLocalizedMessage());
                 }
             }
             result.put(wave, things);

src/main/java/com/garbagemule/MobArena/MobArena.java

@@ -100,7 +100,12 @@ public class MobArena extends JavaPlugin
 
         // Set up the ArenaMaster
         arenaMaster = new ArenaMasterImpl(this);
-        arenaMaster.initialize();
+        try {
+            arenaMaster.initialize();
+        } catch (ConfigError e) {
+            getLogger().severe(e.getMessage());
+            return;
+        }
 
         // Load signs after Messenger and ArenaMaster
         reloadSigns();

src/main/java/com/garbagemule/MobArena/things/InvalidThingInputString.java

@@ -0,0 +1,14 @@
+package com.garbagemule.MobArena.things;
+
+public class InvalidThingInputString extends RuntimeException {
+    private String input;
+
+    InvalidThingInputString(String input) {
+        super("Invalid input: " + input);
+        this.input = input;
+    }
+
+    public String getInput() {
+        return input;
+    }
+}

src/main/java/com/garbagemule/MobArena/things/ThingManager.java

@@ -64,6 +64,22 @@ public class ThingManager implements ThingParser {
 
     @Override
     public Thing parse(String s) {
+        Thing thing = parseThing(s);
+        if (thing != null) {
+            return thing;
+        }
+        throw new InvalidThingInputString(s);
+    }
+
+    public Thing parse(String prefix, String s) {
+        Thing thing = parseThing(prefix + ":" + s);
+        if (thing != null) {
+            return thing;
+        }
+        throw new InvalidThingInputString(s);
+    }
+
+    private Thing parseThing(String s) {
         for (ThingParser parser : parsers) {
             Thing thing = parser.parse(s);
             if (thing != null) {

src/main/java/com/garbagemule/MobArena/waves/WaveParser.java

@@ -1,7 +1,9 @@
 package com.garbagemule.MobArena.waves;
 
+import com.garbagemule.MobArena.ConfigError;
 import com.garbagemule.MobArena.framework.Arena;
 import com.garbagemule.MobArena.region.ArenaRegion;
+import com.garbagemule.MobArena.things.InvalidThingInputString;
 import com.garbagemule.MobArena.things.Thing;
 import com.garbagemule.MobArena.things.ThingManager;
 import com.garbagemule.MobArena.util.ItemParser;
@@ -134,7 +136,7 @@ public class WaveParser
         List<Location> spawnpoints = getSpawnpoints(arena, name, config);
         
         // Potion effects
-        List<PotionEffect> effects = getPotionEffects(config);
+        List<PotionEffect> effects = getPotionEffects(arena, name, config);
 
         // Recurrent must have priority + frequency, single must have firstWave
         if (branch == WaveBranch.RECURRENT && (priority == -1 || frequency <= 0)) {
@@ -238,7 +240,7 @@ public class WaveParser
     
     private static Wave parseUpgradeWave(Arena arena, String name, ConfigurationSection config) {
         ThingManager thingman = arena.getPlugin().getThingManager();
-        Map<String,List<Thing>> upgrades = getUpgradeMap(config, thingman);
+        Map<String,List<Thing>> upgrades = getUpgradeMap(config, name, arena, thingman);
         if (upgrades == null || upgrades.isEmpty()) {
             arena.getPlugin().getLogger().warning(WaveError.UPGRADE_MAP_MISSING.format(name, arena.configName()));
             return null;
@@ -307,13 +309,9 @@ public class WaveParser
         if (rew != null) {
             try {
                 Thing thing = arena.getPlugin().getThingManager().parse(rew.trim());
-                if (thing == null) {
+                result.setReward(thing);
-                    arena.getPlugin().getLogger().warning("Failed to parse boss reward: " + rew.trim());
+            } catch (InvalidThingInputString e) {
-                } else {
+                throw new ConfigError("Failed to parse boss reward in wave " + name + " of arena " + arena.configName() + ": " + e.getInput());
-                    result.setReward(thing);
-                }
-            } catch (Exception e) {
-                arena.getPlugin().getLogger().severe("Exception parsing boss reward '" + rew.trim() + "': " + e.getLocalizedMessage());
             }
         }
 
@@ -404,27 +402,41 @@ public class WaveParser
         return result;
     }
 
-    private static List<PotionEffect> getPotionEffects(ConfigurationSection config) {
+    private static List<PotionEffect> getPotionEffects(Arena arena, String name, ConfigurationSection config) {
-        String value = config.getString("effects");
+        /*
-        if (value == null) {
+         * TODO: Make this consistent with the rest somehow
-            value = config.getString("potions");
+         * - Things only work for Players (currently)
+         */
+        List<String> effects = config.getStringList("effects");
+        if (effects == null || effects.isEmpty()) {
+            String value = config.getString("effects", null);
+            if (value != null && !value.isEmpty()) {
+                effects = Arrays.asList(value.split(","));
+            } else {
+                effects = config.getStringList("potions");
+                if (effects == null || effects.isEmpty()) {
+                    value = config.getString("potions", null);
+                    if (value != null && !value.isEmpty()) {
+                        effects = Arrays.asList(value.split(","));
+                    } else {
+                        return Collections.emptyList();
+                    }
+                }
+            }
         }
-        if (value != null) {
+        return effects.stream()
-            List<PotionEffect> parsed = PotionEffectParser.parsePotionEffects(value);
+            .map(String::trim)
-            return (parsed != null) ? parsed : Collections.emptyList();
+            .map(input -> {
-        }
+                PotionEffect effect = PotionEffectParser.parsePotionEffect(input, false);
-
+                if (effect == null) {
-        List<String> list = config.getStringList("effects");
+                    throw new ConfigError("Failed to parse potion effect for wave " + name + " of arena " + arena.configName() + ": " + input);
-        if (list.isEmpty()) {
+                }
-            list = config.getStringList("potions");
+                return effect;
-        }
+            })
-        return list.stream()
-            .map(PotionEffectParser::parsePotionEffect)
-            .filter(Objects::nonNull)
             .collect(Collectors.toList());
     }
     
-    private static Map<String,List<Thing>> getUpgradeMap(ConfigurationSection config, ThingManager thingman) {
+    private static Map<String,List<Thing>> getUpgradeMap(ConfigurationSection config, String name, Arena arena, ThingManager thingman) {
         ConfigurationSection section = config.getConfigurationSection("upgrades");
         if (section == null) {
             return null;
@@ -442,54 +454,12 @@ public class WaveParser
             // Legacy support
             Object val = config.get(path + className, null);
             if (val instanceof String) {
-                String s = (String) val;
+                List<Thing> things = loadUpgradesFromString(className, (String) val, name, arena, thingman);
-                List<Thing> things = Arrays.asList(s.split(",")).stream()
-                    .map(String::trim)
-                    .map(thingman::parse)
-                    .filter(Objects::nonNull)
-                    .collect(Collectors.toList());
                 upgrades.put(className.toLowerCase(), things);
             }
             // New complex setup
             else if (val instanceof ConfigurationSection) {
-                ConfigurationSection classSection = (ConfigurationSection) val;
+                List<Thing> list = loadUpgradesFromSection(className, (ConfigurationSection) val, name, arena, thingman);
-                List<Thing> list = new ArrayList<>();
-
-                // Items
-                List<String> items = classSection.getStringList("items");
-                if (items == null || items.isEmpty()) {
-                    String value = classSection.getString("items", "");
-                    items = Arrays.asList(value.split(","));
-                }
-                items.stream()
-                    .map(String::trim)
-                    .map(thingman::parse)
-                    .filter(Objects::nonNull)
-                    .forEach(list::add);
-
-                // Armor
-                List<String> armor = classSection.getStringList("armor");
-                if (armor == null || armor.isEmpty()) {
-                    String value = classSection.getString("armor", "");
-                    armor = Arrays.asList(value.split(","));
-                }
-
-                // Prepend "armor:" for the armor thing parser
-                armor.stream()
-                    .map(String::trim)
-                    .map(s -> "armor:" + s)
-                    .map(thingman::parse)
-                    .filter(Objects::nonNull)
-                    .forEach(list::add);
-
-                // Prepend "perm:" for the permission thing parser
-                classSection.getStringList("permissions").stream()
-                    .map(perm -> "perm:" + perm)
-                    .map(thingman::parse)
-                    .filter(Objects::nonNull)
-                    .forEach(list::add);
-
-                // Put in the map
                 upgrades.put(className.toLowerCase(), list);
             }
         }
@@ -497,6 +467,74 @@ public class WaveParser
         return upgrades;
     }
 
+    private static List<Thing> loadUpgradesFromString(String className, String value, String name, Arena arena, ThingManager thingman) {
+        if (value == null || value.isEmpty()) {
+            return Collections.emptyList();
+        }
+        try {
+            return Arrays.stream(value.split(","))
+                .map(String::trim)
+                .map(thingman::parse)
+                .collect(Collectors.toList());
+        } catch (InvalidThingInputString e) {
+            throw new ConfigError("Failed to parse upgrades for class " + className + " in wave " + name + " of arena " + arena.configName() + ": " + e.getInput());
+        }
+    }
+
+    private static List<Thing> loadUpgradesFromSection(String className, ConfigurationSection classSection, String name, Arena arena, ThingManager thingman) {
+        List<Thing> list = new ArrayList<>();
+
+        // Items
+        List<String> items = classSection.getStringList("items");
+        if (items == null || items.isEmpty()) {
+            String value = classSection.getString("items", null);
+            if (value == null || value.isEmpty()) {
+                items = Collections.emptyList();
+            } else {
+                items = Arrays.asList(value.split(","));
+            }
+        }
+        try {
+            items.stream()
+                .map(String::trim)
+                .map(thingman::parse)
+                .forEach(list::add);
+        } catch (InvalidThingInputString e) {
+            throw new ConfigError("Failed to parse item upgrades for class " + className + " in wave " + name + " of arena " + arena.configName() + ": " + e.getInput());
+        }
+
+        // Armor
+        List<String> armor = classSection.getStringList("armor");
+        if (armor == null || armor.isEmpty()) {
+            String value = classSection.getString("armor", null);
+            if (value == null || value.isEmpty()) {
+                armor = Collections.emptyList();
+            } else {
+                armor = Arrays.asList(value.split(","));
+            }
+        }
+        try {
+            // Prepend "armor:" for the armor thing parser
+            armor.stream()
+                .map(String::trim)
+                .map(s -> thingman.parse("armor", s))
+                .forEach(list::add);
+        } catch (InvalidThingInputString e) {
+            throw new ConfigError("Failed to parse armor upgrades for class " + className + " in wave " + name + " of arena " + arena.configName() + ": " + e.getInput());
+        }
+
+        try {
+            // Prepend "perm:" for the permission thing parser
+            classSection.getStringList("permissions").stream()
+                .map(perm -> thingman.parse("perm", perm))
+                .forEach(list::add);
+        } catch (InvalidThingInputString e) {
+            throw new ConfigError("Failed to parse permission upgrades for class " + className + " in wave " + name + " of arena " + arena.configName() + ": " + e.getInput());
+        }
+
+        return list;
+    }
+    
     public static Wave createDefaultWave() {
         SortedMap<Integer,MACreature> monsters = new TreeMap<>();
         monsters.put(10, MACreature.ZOMBIE);

src/test/java/com/garbagemule/MobArena/things/ThingManagerTest.java

@@ -1,7 +1,6 @@
 package com.garbagemule.MobArena.things;
 
-import static org.hamcrest.CoreMatchers.nullValue;
+import static org.mockito.ArgumentMatchers.anyString;
-import static org.hamcrest.MatcherAssert.assertThat;
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
@@ -10,13 +9,18 @@ import static org.mockito.Mockito.when;
 
 import com.garbagemule.MobArena.MobArena;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 import org.mockito.InOrder;
 
 public class ThingManagerTest {
 
     private ThingManager subject;
 
+    @Rule
+    public ExpectedException exception = ExpectedException.none();
+
     @Before
     public void setup() {
         MobArena plugin = mock(MobArena.class);
@@ -27,6 +31,7 @@ public class ThingManagerTest {
     public void afterCoreParsersInOrder() {
         ThingParser first = mock(ThingParser.class);
         ThingParser second = mock(ThingParser.class);
+        when(second.parse(anyString())).thenReturn(mock(Thing.class));
         subject.register(first /*, false */);
         subject.register(second /*, false */);
 
@@ -41,6 +46,7 @@ public class ThingManagerTest {
     public void beforeCoreParsersInverseOrder() {
         ThingParser first = mock(ThingParser.class);
         ThingParser second = mock(ThingParser.class);
+        when(first.parse(anyString())).thenReturn(mock(Thing.class));
         subject.register(first, true);
         subject.register(second, true);
 
@@ -72,7 +78,7 @@ public class ThingManagerTest {
     }
 
     @Test
-    public void returnsNullIfNoParsersSucceed() {
+    public void throwsIfNoParsersSucceed() {
         ThingParser first = mock(ThingParser.class);
         ThingParser second = mock(ThingParser.class);
         when(first.parse("thing")).thenReturn(null);
@@ -80,9 +86,9 @@ public class ThingManagerTest {
         subject.register(first);
         subject.register(second);
 
-        Thing result = subject.parse("thing");
+        exception.expect(InvalidThingInputString.class);
 
-        assertThat(result, nullValue());
+        subject.parse("thing");
     }
 
 }