Improve the error message when return type does not matched the CharSequence or its subclass

See gh-1279

Author: kazuki43zoo

src/main/java/org/apache/ibatis/builder/annotation/ProviderMethodResolver.java

@@ -18,7 +18,6 @@
 
 import java.lang.reflect.Method;
 import java.util.Arrays;
-import java.util.Date;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -50,18 +49,25 @@ public interface ProviderMethodResolver {
    * @throws BuilderException Throws when cannot resolve a target method
    */
   default Method resolveMethod(ProviderContext context) {
-    List<Method> targetMethods = Arrays.stream(getClass().getMethods())
+    List<Method> sameNameMethods = Arrays.stream(getClass().getMethods())
         .filter(m -> m.getName().equals(context.getMapperMethod().getName()))
+        .collect(Collectors.toList());
+    if (sameNameMethods.isEmpty()) {
+      throw new BuilderException("Cannot resolve the provider method because '"
+          + context.getMapperMethod().getName() + "' not found in SqlProvider '" + getClass().getName() + "'.");
+    }
+    List<Method> targetMethods = sameNameMethods.stream()
         .filter(m -> CharSequence.class.isAssignableFrom(m.getReturnType()))
         .collect(Collectors.toList());
     if (targetMethods.size() == 1) {
       return targetMethods.get(0);
     }
     if (targetMethods.isEmpty()) {
-      throw new BuilderException("Cannot resolve the provide method because '"
-          + context.getMapperMethod().getName() + "' not found in SqlProvider '" + getClass().getName() + "'.");
+      throw new BuilderException("Cannot resolve the provider method because '"
+          + context.getMapperMethod().getName() + "' does not return the CharSequence or its subclass in SqlProvider '"
+          + getClass().getName() + "'.");
     } else {
-      throw new BuilderException("Cannot resolve the provide method because '"
+      throw new BuilderException("Cannot resolve the provider method because '"
           + context.getMapperMethod().getName() + "' is found multiple in SqlProvider '" + getClass().getName() + "'.");
     }
   }

src/test/java/org/apache/ibatis/submitted/sqlprovider/ProviderMethodResolutionTest.java

@@ -66,11 +66,20 @@ void shouldResolveWhenDefaultResolverMatchedMethodIsOne() {
   }
 
   @Test
-  void shouldErrorWhenDefaultResolverMatchedMethodIsNone() {
+  void shouldErrorWhenDefaultResolverMethodNameMatchedMethodIsNone() {
     BuilderException e = Assertions.assertThrows(BuilderException.class,
-        () -> sqlSessionFactory.getConfiguration().addMapper(DefaultProvideMethodResolverMatchedMethodIsNoneMapper.class));
+        () -> sqlSessionFactory.getConfiguration().addMapper(DefaultProvideMethodResolverMethodNameMatchedMethodIsNoneMapper.class));
     assertEquals(
-        "Cannot resolve the provide method because 'insert' not found in SqlProvider 'org.apache.ibatis.submitted.sqlprovider.ProviderMethodResolutionTest$DefaultProvideMethodResolverMatchedMethodIsNoneMapper$MethodResolverBasedSqlProvider'.",
+        "Cannot resolve the provider method because 'insert' not found in SqlProvider 'org.apache.ibatis.submitted.sqlprovider.ProviderMethodResolutionTest$DefaultProvideMethodResolverMethodNameMatchedMethodIsNoneMapper$MethodResolverBasedSqlProvider'.",
+        e.getCause().getMessage());
+  }
+
+  @Test
+  void shouldErrorWhenDefaultResolverReturnTypeMatchedMethodIsNone() {
+    BuilderException e = Assertions.assertThrows(BuilderException.class,
+        () -> sqlSessionFactory.getConfiguration().addMapper(DefaultProvideMethodResolverReturnTypeMatchedMethodIsNoneMapper.class));
+    assertEquals(
+        "Cannot resolve the provider method because 'insert' does not return the CharSequence or its subclass in SqlProvider 'org.apache.ibatis.submitted.sqlprovider.ProviderMethodResolutionTest$DefaultProvideMethodResolverReturnTypeMatchedMethodIsNoneMapper$MethodResolverBasedSqlProvider'.",
         e.getCause().getMessage());
   }
 
@@ -79,7 +88,7 @@ void shouldErrorWhenDefaultResolverMatchedMethodIsMultiple() {
     BuilderException e = Assertions.assertThrows(BuilderException.class,
         () -> sqlSessionFactory.getConfiguration().addMapper(DefaultProvideMethodResolverMatchedMethodIsMultipleMapper.class));
     assertEquals(
-        "Cannot resolve the provide method because 'update' is found multiple in SqlProvider 'org.apache.ibatis.submitted.sqlprovider.ProviderMethodResolutionTest$DefaultProvideMethodResolverMatchedMethodIsMultipleMapper$MethodResolverBasedSqlProvider'.",
+        "Cannot resolve the provider method because 'update' is found multiple in SqlProvider 'org.apache.ibatis.submitted.sqlprovider.ProviderMethodResolutionTest$DefaultProvideMethodResolverMatchedMethodIsMultipleMapper$MethodResolverBasedSqlProvider'.",
         e.getCause().getMessage());
   }
 
@@ -187,7 +196,20 @@ default Method resolveMethod(ProviderContext context) {
     }
   }
 
-  interface DefaultProvideMethodResolverMatchedMethodIsNoneMapper {
+  interface DefaultProvideMethodResolverMethodNameMatchedMethodIsNoneMapper {
+
+    @InsertProvider(type = MethodResolverBasedSqlProvider.class)
+    int insert();
+
+    class MethodResolverBasedSqlProvider implements ProviderMethodResolver {
+      public static String provideInsertSql() {
+        return "INSERT INTO foo (name) VALUES(#{name})";
+      }
+    }
+
+  }
+
+  interface DefaultProvideMethodResolverReturnTypeMatchedMethodIsNoneMapper {
 
     @InsertProvider(type = MethodResolverBasedSqlProvider.class)
     int insert();