Improve property target name

Previously, non camel case properties were wrongly resolved, i.e.
getFOO() leading to a 'f-o-o'. While unusual, underscores can also be
added to a property name. In that case, the hyphen should not be added
as the binder consider this to be a single "word". Typically setFoo_Bar
on the "something" prefix is mapped using "something.foo_bar".

All these cases are now handled properly, generating the target name that
the binder expects.

Fixes gh-2118

spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/metadata/ConfigurationMetadataTests.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.configurationprocessor.metadata;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+/**
+ * Tests for {@link ConfigurationMetadata}.
+ *
+ * @author Stephane Nicoll
+ */
+public class ConfigurationMetadataTests {
+
+	@Test
+	public void toDashedCaseCamelCase() {
+		assertThat(ConfigurationMetadata.toDashedCase("simpleCamelCase"), is("simple-camel-case"));
+	}
+
+	@Test
+	public void toDashedCaseWordsUnderScore() {
+		assertThat(ConfigurationMetadata.toDashedCase("Word_With_underscore"), is("word_with_underscore"));
+	}
+
+	@Test
+	public void toDashedCaseWordsSeveralUnderScores() {
+		assertThat(ConfigurationMetadata.toDashedCase("Word___With__underscore"), is("word___with__underscore"));
+	}
+
+	@Test
+	public void toDashedCaseLowerCaseUnderscore() {
+		assertThat(ConfigurationMetadata.toDashedCase("lower_underscore"), is("lower_underscore"));
+	}
+
+	@Test
+	public void toDashedCaseUpperUnderscore() {
+		assertThat(ConfigurationMetadata.toDashedCase("UPPER_UNDERSCORE"), is("upper_underscore"));
+	}
+
+	@Test
+	public void toDashedCaseMultipleUnderscores() {
+		assertThat(ConfigurationMetadata.toDashedCase("super___crazy"), is("super___crazy"));
+	}
+
+	@Test
+	public void toDashedCaseUppercase() {
+		assertThat(ConfigurationMetadata.toDashedCase("UPPERCASE"), is("uppercase"));
+	}
+
+	@Test
+	public void toDashedCaseLowercase() {
+		assertThat(ConfigurationMetadata.toDashedCase("lowercase"), is("lowercase"));
+	}
+
+}