From 14097436feb7acaec2fa230daf2ad8d773f92ff7 Mon Sep 17 00:00:00 2001
From: A248 <theanandbeh@gmail.com>
Date: Sat, 4 Dec 2021 10:29:45 -0500
Subject: [PATCH] Disallow null values in collection elements - Fixes #23

---
 .../arim/dazzleconf/internal/NestedMapHelper.java |  2 +-
 .../arim/dazzleconf/internal/error/UserError.java |  6 ++++++
 .../internal/processor/FlexibleTypeImpl.java      | 15 ++++++++++-----
 .../ext/snakeyaml/NullListElementTest.java        | 15 ++++++---------
 4 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/core/src/main/java/space/arim/dazzleconf/internal/NestedMapHelper.java b/core/src/main/java/space/arim/dazzleconf/internal/NestedMapHelper.java
index 7eaec1e..2cd54e3 100644
--- a/core/src/main/java/space/arim/dazzleconf/internal/NestedMapHelper.java
+++ b/core/src/main/java/space/arim/dazzleconf/internal/NestedMapHelper.java
@@ -170,7 +170,7 @@ public Object get(String key) throws MissingKeyException, MissingValueException
 		if (value == null) {
 			if (currentMap.containsKey(keyParts[lastIndex])) {
 				// Null value
-				throw MissingValueException.forKeyAndMessage(key, UserError.missingKey(key));
+				throw MissingValueException.forKeyAndMessage(key, UserError.nullValue(key));
 			} else {
 				// Absent value
 				throw MissingKeyException.forKeyAndMessage(key, UserError.missingKey(key));
diff --git a/core/src/main/java/space/arim/dazzleconf/internal/error/UserError.java b/core/src/main/java/space/arim/dazzleconf/internal/error/UserError.java
index 2649311..58b6f2b 100644
--- a/core/src/main/java/space/arim/dazzleconf/internal/error/UserError.java
+++ b/core/src/main/java/space/arim/dazzleconf/internal/error/UserError.java
@@ -71,6 +71,12 @@ public static UserError missingKey(String key) {
 						"the configuration option at " + key + ", then set it to a valid value.");
 	}
 
+	public static UserError nullValue(String key) {
+		return new UserError(Errors.When.LOAD_CONFIG,
+				"The configuration option at " + key + " was set to an empty value. " +
+						"You must set it to a valid value - it cannot be empty.");
+	}
+
 	@Override
 	public Errors.When when() {
 		return when;
diff --git a/core/src/main/java/space/arim/dazzleconf/internal/processor/FlexibleTypeImpl.java b/core/src/main/java/space/arim/dazzleconf/internal/processor/FlexibleTypeImpl.java
index de900ea..98fef8f 100644
--- a/core/src/main/java/space/arim/dazzleconf/internal/processor/FlexibleTypeImpl.java
+++ b/core/src/main/java/space/arim/dazzleconf/internal/processor/FlexibleTypeImpl.java
@@ -58,10 +58,10 @@ final class FlexibleTypeImpl implements FlexibleType {
 
 	FlexibleTypeImpl(String key, Object value, ConfigurationOptions options,
 			ValueSerialiserMap serialisers) {
-		this.key = key;
-		this.value = value;
-		this.options = options;
-		this.serialisers = serialisers;
+		this.key = Objects.requireNonNull(key, "key");
+		this.value = Objects.requireNonNull(value, "value");
+		this.options = Objects.requireNonNull(options, "options");
+		this.serialisers = Objects.requireNonNull(serialisers, "serialisers");
 	}
 
 	@Override
@@ -260,7 +260,12 @@ public <K, V> Map<K, V> getMap(FlexibleTypeMapEntryFunction<? extends K, ? exten
 		return ImmutableCollections.mapOf(result);
 	}
 
-	private FlexibleTypeImpl deriveFlexibleObject(Object value) {
+	private FlexibleTypeImpl deriveFlexibleObject(Object value) throws BadValueException {
+		if (value == null) {
+			throw badValueExceptionBuilder()
+					.message(UserError.nullValue(key))
+					.build();
+		}
 		return new FlexibleTypeImpl(key, value, options, serialisers);
 	}
 
diff --git a/snakeyaml/src/test/java/space/arim/dazzleconf/ext/snakeyaml/NullListElementTest.java b/snakeyaml/src/test/java/space/arim/dazzleconf/ext/snakeyaml/NullListElementTest.java
index 7de1739..9f9c76b 100644
--- a/snakeyaml/src/test/java/space/arim/dazzleconf/ext/snakeyaml/NullListElementTest.java
+++ b/snakeyaml/src/test/java/space/arim/dazzleconf/ext/snakeyaml/NullListElementTest.java
@@ -19,9 +19,9 @@
 
 package space.arim.dazzleconf.ext.snakeyaml;
 
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import space.arim.dazzleconf.ConfigurationOptions;
+import space.arim.dazzleconf.error.BadValueException;
 import space.arim.dazzleconf.error.InvalidConfigException;
 
 import java.io.ByteArrayInputStream;
@@ -29,12 +29,10 @@
 import java.nio.charset.StandardCharsets;
 import java.util.List;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 public class NullListElementTest {
 
-	@Disabled("Fix scheduled for 1.3.0. See https://github.com/A248/DazzleConf/issues/23")
 	@Test
 	public void readLiteralNullListElement() throws IOException, InvalidConfigException {
 		String content = """
@@ -43,11 +41,10 @@ public void readLiteralNullListElement() throws IOException, InvalidConfigExcept
 				  - 'value2'
 				  """;
 		var factory = SnakeYamlConfigurationFactory.create(ListConfig.class, ConfigurationOptions.defaults());
-		ListConfig config = factory.load(new ByteArrayInputStream(content.getBytes(StandardCharsets.UTF_8)));
-		assertEquals(List.of("value2"), config.list());
+		var data = new ByteArrayInputStream(content.getBytes(StandardCharsets.UTF_8));
+		assertThrows(BadValueException.class, () -> factory.load(data));
 	}
 
-	@Disabled("See prior")
 	@Test
 	public void readImplicitNullListElement() throws IOException, InvalidConfigException {
 		String content = """
@@ -56,8 +53,8 @@ public void readImplicitNullListElement() throws IOException, InvalidConfigExcep
 				  -\040
 				  """;
 		var factory = SnakeYamlConfigurationFactory.create(ListConfig.class, ConfigurationOptions.defaults());
-		ListConfig config = factory.load(new ByteArrayInputStream(content.getBytes(StandardCharsets.UTF_8)));
-		assertEquals(List.of("value1"), config.list());
+		var data = new ByteArrayInputStream(content.getBytes(StandardCharsets.UTF_8));
+		assertThrows(BadValueException.class, () -> factory.load(data));
 	}
 
 	public interface ListConfig {