Source value mapped more than once inspection for @ValueMapping

For value mappings a source value can only be mapped once. For example

import org.mapstruct.Mapper;
import org.mapstruct.ValueMapping;

@Mapper
public interface ValueMapper {

    enum A {
        A,B
    }

    enum B {
        A,B
    }

    @ValueMapping(source = "A", target = "B")
    @ValueMapping(source = "A", target = "A")
    A from(B b);
}

is invalide as source A is mapped twice. MapStruct report this as

Source value mapping: "A" cannot be mapped more than once.

Currently the plugin does not recognize this as an error. An inspection should be added for this.

For normal mappings there is already an inspection implemented and could be used as an example: https://github.com/mapstruct/mapstruct-idea/blob/main/src/main/java/org/mapstruct/intellij/inspection/TargetPropertyMappedMoreThanOnceInspection.java.

從 src/main/java/org/mapstruct/intellij/inspection/TargetPropertyMappedMoreThanOnceInspection.java 開始，該檔案提供了現有的 inspection 模式。追蹤它如何偵測重複的一般 mapping，然後對 @ValueMapping 的來源值套用相同的方法。完成的標準是能夠識別重複的來源值，並使用預期的錯誤訊息進行回報。