WX_EXPORT_METHOD是暴露module方法的宏定义，展开后为：

#define WX_EXPORT_METHOD(method)

+ (NSString *)wx_export_method_ __LINE__ { \
    return NSStringFromSelector(method); \
}

注册方法在WXInvocationConfig里的registerMethods里，代码如下：

- (void)registerMethods
{
    Class currentClass = NSClassFromString(_clazz);
    
    if (!currentClass) {
        WXLogWarning(@"The module class [%@] doesn't exit！", _clazz);
        return;
    }
    
    while (currentClass != [NSObject class]) {
        unsigned int methodCount = 0;
        Method *methodList = class_copyMethodList(object_getClass(currentClass), &methodCount);
        for (unsigned int i = 0; i < methodCount; i++) {
            NSString *selStr = [NSString stringWithCString:sel_getName(method_getName(methodList[i])) encoding:NSUTF8StringEncoding];
            BOOL isSyncMethod = NO;
            if ([selStr hasPrefix:@"wx_export_method_sync_"]) {
                isSyncMethod = YES;
            } else if ([selStr hasPrefix:@"wx_export_method_"]) {
                isSyncMethod = NO;
            } else {
                continue;
            }
            
            NSString *name = nil, *method = nil;
            SEL selector = NSSelectorFromString(selStr);
            if ([currentClass respondsToSelector:selector]) {
                method = ((NSString* (*)(id, SEL))[currentClass methodForSelector:selector])(currentClass, selector);
            }
            
            if (method.length <= 0) {
                WXLogWarning(@"The module class [%@] doesn't has any method！", _clazz);
                continue;
            }
            // 以冒号为分割，获取前半部分为方法名
            NSRange range = [method rangeOfString:@":"];
            if (range.location != NSNotFound) {
                name = [method substringToIndex:range.location];
            } else {
                name = method;
            }
            
            NSMutableDictionary *methods = isSyncMethod ? _syncMethods : _asyncMethods;
            [methods setObject:method forKey:name];
        }
        
        free(methodList);
        currentClass = class_getSuperclass(currentClass);
    }
    
}

可以看到，他用冒号来分割了字符串，只取了前半部分为方法字典的key，因此这样的两个方法：WX_EXPORT_METHOD(@selector(test:param:)) 和 @selector(test:)在同一个module里会互相覆盖，只保留了前一个。这点需要在写方法的时候加以注意。

参考资料：https://halfrost.com/weex_ios/