Fix binding of Flyway's baselineVersion property

See gh-4317

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration.java

@@ -21,6 +21,7 @@ import javax.persistence.EntityManagerFactory;
 import javax.sql.DataSource;
 
 import org.flywaydb.core.Flyway;
+import org.flywaydb.core.api.MigrationVersion;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
@@ -33,9 +34,11 @@ import org.springframework.boot.autoconfigure.data.jpa.EntityManagerFactoryDepen
 import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
 import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.context.properties.ConfigurationPropertiesBinding;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.io.DefaultResourceLoader;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.orm.jpa.AbstractEntityManagerFactoryBean;
@@ -47,6 +50,7 @@ import org.springframework.util.Assert;
  *
  * @author Dave Syer
  * @author Phillip Webb
+ * @author Vedran Pavic
  * @since 1.1.0
  */
 @Configuration
@@ -57,6 +61,12 @@ import org.springframework.util.Assert;
 		HibernateJpaAutoConfiguration.class })
 public class FlywayAutoConfiguration {
 
+	@Bean
+	@ConfigurationPropertiesBinding
+	public StringToMigrationVersionConverter stringToMigrationVersionConverter() {
+		return new StringToMigrationVersionConverter();
+	}
+
 	@Configuration
 	@ConditionalOnMissingBean(Flyway.class)
 	@EnableConfigurationProperties(FlywayProperties.class)
@@ -158,4 +168,16 @@ public class FlywayAutoConfiguration {
 
 	}
 
+	/**
+	 * Converts a String to a {@link MigrationVersion}.
+	 */
+	private static class StringToMigrationVersionConverter implements Converter<String, MigrationVersion> {
+
+		@Override
+		public MigrationVersion convert(String source) {
+			return MigrationVersion.fromVersion(source);
+		}
+
+	}
+
 }

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/flyway/FlywayAutoConfigurationTests.java

@@ -23,6 +23,7 @@ import java.util.Map;
 import javax.sql.DataSource;
 
 import org.flywaydb.core.Flyway;
+import org.flywaydb.core.api.MigrationVersion;
 import org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform;
 import org.junit.After;
 import org.junit.Before;
@@ -56,6 +57,7 @@ import static org.junit.Assert.assertThat;
  * @author Dave Syer
  * @author Phillip Webb
  * @author Andy Wilkinson
+ * @author Vedran Pavic
  */
 public class FlywayAutoConfigurationTests {
 
@@ -195,6 +197,16 @@ public class FlywayAutoConfigurationTests {
 				PropertyPlaceholderAutoConfiguration.class);
 	}
 
+	@Test
+	public void overrideBaselineVersion() throws Exception {
+		EnvironmentTestUtils.addEnvironment(this.context, "flyway.baseline-version=0");
+		registerAndRefresh(EmbeddedDataSourceConfiguration.class,
+				FlywayAutoConfiguration.class,
+				PropertyPlaceholderAutoConfiguration.class);
+		Flyway flyway = this.context.getBean(Flyway.class);
+		assertThat(flyway.getBaselineVersion(), equalTo(MigrationVersion.fromVersion("0")));
+	}
+
 	private void registerAndRefresh(Class<?>... annotatedClasses) {
 		this.context.register(annotatedClasses);
 		this.context.refresh();