Optimize code

2024-02-20 17:32:20 +08:00
parent 46a603b924
commit 45a5ee1c54
16 changed files with 75 additions and 111 deletions
--- a/src/main/kotlin/top/fatweb/oxygen/api/config/DateFormatConfig.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/config/DateFormatConfig.kt
@@ -6,7 +6,6 @@ import org.springframework.beans.factory.annotation.Value
 import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer
 import org.springframework.boot.jackson.JsonComponent
 import org.springframework.context.annotation.Bean
-import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder
 import java.text.DateFormat
 import java.text.SimpleDateFormat
 import java.time.LocalDateTime
@@ -41,18 +40,18 @@ class DateFormatConfig {
    lateinit var timeZone: TimeZone

    @Bean
-    fun jackson2ObjectMapperBuilder() = Jackson2ObjectMapperBuilderCustomizer { builder: Jackson2ObjectMapperBuilder ->
+    fun jackson2ObjectMapperBuilder() = Jackson2ObjectMapperBuilderCustomizer {
        val tz = timeZone
        val df: DateFormat = SimpleDateFormat(dateFormat)
        df.timeZone = tz
-        builder.failOnEmptyBeans(false).failOnUnknownProperties(false)
+        it.failOnEmptyBeans(false).failOnUnknownProperties(false)
            .featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS).dateFormat(df)
    }

    @Bean
    fun jackson2ObjectMapperBuilderCustomizer() =
-        Jackson2ObjectMapperBuilderCustomizer { builder: Jackson2ObjectMapperBuilder ->
-            builder.serializerByType(
+        Jackson2ObjectMapperBuilderCustomizer {
+            it.serializerByType(
                LocalDateTime::class.java, LocalDateTimeSerializer(DateTimeFormatter.ofPattern(dateFormat))
            )
        }
--- a/src/main/kotlin/top/fatweb/oxygen/api/config/SecurityConfig.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/config/SecurityConfig.kt
@@ -6,7 +6,6 @@ import org.springframework.security.authentication.AuthenticationManager
 import org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration
 import org.springframework.security.config.annotation.method.configuration.EnableMethodSecurity
 import org.springframework.security.config.annotation.web.builders.HttpSecurity
-import org.springframework.security.config.annotation.web.configurers.*
 import org.springframework.security.config.http.SessionCreationPolicy
 import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder
 import org.springframework.security.web.SecurityFilterChain
@@ -56,15 +55,17 @@ class SecurityConfig(
    @Bean
    fun securityFilterChain(httpSecurity: HttpSecurity): SecurityFilterChain = httpSecurity
        //  Disable CSRF
-        .csrf { csrfConfigurer: CsrfConfigurer<HttpSecurity> -> csrfConfigurer.disable() }
+        .csrf {
+            it.disable()
+        }
        // Do not get SecurityContent by Session
-        .sessionManagement { sessionManagementConfigurer: SessionManagementConfigurer<HttpSecurity?> ->
-            sessionManagementConfigurer.sessionCreationPolicy(
+        .sessionManagement {
+            it.sessionCreationPolicy(
                SessionCreationPolicy.STATELESS
            )
        }
-        .authorizeHttpRequests { authorizeHttpRequests: AuthorizeHttpRequestsConfigurer<HttpSecurity>.AuthorizationManagerRequestMatcherRegistry ->
-            authorizeHttpRequests
+        .authorizeHttpRequests {
+            it
                // Allow anonymous access
                .requestMatchers(
                    "/error/thrown",
@@ -84,19 +85,21 @@ class SecurityConfig(
                .anyRequest().authenticated()
        }

-        .logout { logoutConfigurer: LogoutConfigurer<HttpSecurity> -> logoutConfigurer.disable() }
+        .logout {
+            it.disable()
+        }

-        .exceptionHandling { exceptionHandlingConfigurer: ExceptionHandlingConfigurer<HttpSecurity?> ->
-            exceptionHandlingConfigurer.authenticationEntryPoint(
+        .exceptionHandling {
+            it.authenticationEntryPoint(
                authenticationEntryPointHandler
            )
-            exceptionHandlingConfigurer.accessDeniedHandler(
+            it.accessDeniedHandler(
                accessDeniedHandler
            )
        }

-        .cors { cors: CorsConfigurer<HttpSecurity?> ->
-            cors.configurationSource(
+        .cors {
+            it.configurationSource(
                corsConfigurationSource()
            )
        }
--- a/src/main/kotlin/top/fatweb/oxygen/api/converter/permission/GroupConverter.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/converter/permission/GroupConverter.kt
@@ -51,7 +51,7 @@ object GroupConverter {
        enable = group.enable == 1,
        createTime = group.createTime,
        updateTime = group.updateTime,
-        roles = group.roles?.map { RoleConverter.roleToRoleVo(it) }
+        roles = group.roles?.map(RoleConverter::roleToRoleVo)
    )

    /**
@@ -71,9 +71,7 @@ object GroupConverter {
        pages = groupPage.pages,
        size = groupPage.size,
        current = groupPage.current,
-        records = groupPage.records.map {
-            groupToGroupWithRoleVo(it)
-        }
+        records = groupPage.records.map(::groupToGroupWithRoleVo)
    )

    /**
--- a/src/main/kotlin/top/fatweb/oxygen/api/converter/permission/PowerConverter.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/converter/permission/PowerConverter.kt
@@ -21,9 +21,9 @@ object PowerConverter {
     * @see PowerSetVo
     */
    fun powerSetToPowerSetVo(powerSet: PowerSet) = PowerSetVo(
-        moduleList = powerSet.moduleList?.map { ModuleConverter.moduleToModuleVo(it) },
-        menuList = powerSet.menuList?.map { MenuConverter.menuToMenuVo(it) },
-        funcList = powerSet.funcList?.map { FuncConverter.funcToFuncVo(it) },
-        operationList = powerSet.operationList?.map { OperationConverter.operationToOperationVo(it) }
+        moduleList = powerSet.moduleList?.map(ModuleConverter::moduleToModuleVo),
+        menuList = powerSet.menuList?.map(MenuConverter::menuToMenuVo),
+        funcList = powerSet.funcList?.map(FuncConverter::funcToFuncVo),
+        operationList = powerSet.operationList?.map(OperationConverter::operationToOperationVo)
    )
 }
--- a/src/main/kotlin/top/fatweb/oxygen/api/converter/permission/RoleConverter.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/converter/permission/RoleConverter.kt
@@ -51,10 +51,10 @@ object RoleConverter {
        enable = role.enable == 1,
        createTime = role.createTime,
        updateTime = role.updateTime,
-        modules = role.modules?.map { ModuleConverter.moduleToModuleVo(it) },
-        menus = role.menus?.map { MenuConverter.menuToMenuVo(it) },
-        funcs = role.funcs?.map { FuncConverter.funcToFuncVo(it) },
-        operations = role.operations?.map { OperationConverter.operationToOperationVo(it) }
+        modules = role.modules?.map(ModuleConverter::moduleToModuleVo),
+        menus = role.menus?.map(MenuConverter::menuToMenuVo),
+        funcs = role.funcs?.map(FuncConverter::funcToFuncVo),
+        operations = role.operations?.map(OperationConverter::operationToOperationVo)
    )

    /**
@@ -74,9 +74,7 @@ object RoleConverter {
        pages = rolePage.pages,
        size = rolePage.size,
        current = rolePage.current,
-        records = rolePage.records.map {
-            roleToRoleWithPowerVo(it)
-        }
+        records = rolePage.records.map(::roleToRoleWithPowerVo)
    )

    /**
--- a/src/main/kotlin/top/fatweb/oxygen/api/converter/permission/UserConverter.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/converter/permission/UserConverter.kt
@@ -45,21 +45,11 @@ object UserConverter {
        lastLoginIp = user.lastLoginIp,
        createTime = user.createTime,
        updateTime = user.updateTime,
-        userInfo = user.userInfo?.let {
-            UserInfoConverter.userInfoToUserInfoVo(it)
-        },
-        modules = user.modules?.map {
-            ModuleConverter.moduleToModuleVo(it)
-        },
-        menus = user.menus?.map {
-            MenuConverter.menuToMenuVo(it)
-        },
-        funcs = user.funcs?.map {
-            FuncConverter.funcToFuncVo(it)
-        },
-        operations = user.operations?.map {
-            OperationConverter.operationToOperationVo(it)
-        }
+        userInfo = user.userInfo?.let(UserInfoConverter::userInfoToUserInfoVo),
+        modules = user.modules?.map(ModuleConverter::moduleToModuleVo),
+        menus = user.menus?.map(MenuConverter::menuToMenuVo),
+        funcs = user.funcs?.map(FuncConverter::funcToFuncVo),
+        operations = user.operations?.map(OperationConverter::operationToOperationVo)
    )

    /**
@@ -86,15 +76,9 @@ object UserConverter {
        lastLoginIp = user.lastLoginIp,
        createTime = user.createTime,
        updateTime = user.updateTime,
-        userInfo = user.userInfo?.let {
-            UserInfoConverter.userInfoToUserInfoVo(it)
-        },
-        roles = user.roles?.map {
-            RoleConverter.roleToRoleVo(it)
-        },
-        groups = user.groups?.map {
-            GroupConverter.groupToGroupVo(it)
-        }
+        userInfo = user.userInfo?.let(UserInfoConverter::userInfoToUserInfoVo),
+        roles = user.roles?.map(RoleConverter::roleToRoleVo),
+        groups = user.groups?.map(GroupConverter::groupToGroupVo)
    )

    /**
@@ -121,9 +105,7 @@ object UserConverter {
        lastLoginIp = user.lastLoginIp,
        createTime = user.createTime,
        updateTime = user.updateTime,
-        userInfo = user.userInfo?.let {
-            UserInfoConverter.userInfoToUserInfoVo(it)
-        }
+        userInfo = user.userInfo?.let(UserInfoConverter::userInfoToUserInfoVo)
    )

    /**
@@ -151,15 +133,9 @@ object UserConverter {
        lastLoginIp = user.lastLoginIp,
        createTime = user.createTime,
        updateTime = user.updateTime,
-        userInfo = user.userInfo?.let {
-            UserInfoConverter.userInfoToUserInfoVo(it)
-        },
-        roles = user.roles?.map {
-            RoleConverter.roleToRoleVo(it)
-        },
-        groups = user.groups?.map {
-            GroupConverter.groupToGroupVo(it)
-        }
+        userInfo = user.userInfo?.let(UserInfoConverter::userInfoToUserInfoVo),
+        roles = user.roles?.map(RoleConverter::roleToRoleVo),
+        groups = user.groups?.map(GroupConverter::groupToGroupVo)
    )

    /**
@@ -232,8 +208,6 @@ object UserConverter {
        pages = userPage.pages,
        size = userPage.size,
        current = userPage.current,
-        records = userPage.records.map {
-            userToUserWithRoleInfoVo(it)
-        }
+        records = userPage.records.map(::userToUserWithRoleInfoVo)
    )
 }
--- a/src/main/kotlin/top/fatweb/oxygen/api/converter/tool/ToolConverter.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/converter/tool/ToolConverter.kt
@@ -60,6 +60,6 @@ object ToolConverter {
        pages = toolPage.pages,
        size = toolPage.size,
        current = toolPage.current,
-        records = toolPage.records.map(this::toolToToolVo)
+        records = toolPage.records.map(::toolToToolVo)
    )
 }
--- a/src/main/kotlin/top/fatweb/oxygen/api/filter/JwtAuthenticationTokenFilter.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/filter/JwtAuthenticationTokenFilter.kt
@@ -45,7 +45,7 @@ class JwtAuthenticationTokenFilter(private val redisUtil: RedisUtil) : OncePerRe
        }

        val loginUser = redisUtil.getObject<LoginUser>(redisKeys.first())
-        loginUser ?: let { throw TokenHasExpiredException() }
+        loginUser ?: throw TokenHasExpiredException()

        redisUtil.setExpire(redisKeys.first(), SecurityProperties.redisTtl, SecurityProperties.redisTtlUnit)

--- a/src/main/kotlin/top/fatweb/oxygen/api/service/api/v1/impl/AvatarServiceImpl.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/service/api/v1/impl/AvatarServiceImpl.kt
@@ -59,12 +59,12 @@ class AvatarServiceImpl : IAvatarService {
            if (avatarBaseParam == null || avatarBaseParam.colors.isNullOrEmpty())
                TriangleAvatar.newAvatarBuilder()
            else TriangleAvatar.newAvatarBuilder(
-                *avatarBaseParam.colors!!.map(this::decodeColor).toTypedArray()
+                *avatarBaseParam.colors!!.map(::decodeColor).toTypedArray()
            )
            ).apply {
-                avatarBaseParam?.size?.let(this::size)
-                avatarBaseParam?.margin?.let(this::margin)
-                avatarBaseParam?.padding?.let(this::padding)
+                avatarBaseParam?.size?.let(::size)
+                avatarBaseParam?.margin?.let(::margin)
+                avatarBaseParam?.padding?.let(::padding)
                avatarBaseParam?.background?.let { layers(ColorPaintBackgroundLayer(decodeColor(it))) }
            }.build()

@@ -79,12 +79,12 @@ class AvatarServiceImpl : IAvatarService {
            if (avatarBaseParam == null || avatarBaseParam.colors.isNullOrEmpty())
                SquareAvatar.newAvatarBuilder()
            else SquareAvatar.newAvatarBuilder(
-                *avatarBaseParam.colors!!.map(this::decodeColor).toTypedArray()
+                *avatarBaseParam.colors!!.map(::decodeColor).toTypedArray()
            )
            ).apply {
-                avatarBaseParam?.size?.let(this::size)
-                avatarBaseParam?.margin?.let(this::margin)
-                avatarBaseParam?.padding?.let(this::padding)
+                avatarBaseParam?.size?.let(::size)
+                avatarBaseParam?.margin?.let(::margin)
+                avatarBaseParam?.padding?.let(::padding)
                avatarBaseParam?.background?.let { layers(ColorPaintBackgroundLayer(decodeColor(it))) }
            }.build()

@@ -96,9 +96,9 @@ class AvatarServiceImpl : IAvatarService {

    override fun identicon(avatarBaseParam: AvatarBaseParam?): ByteArray {
        val avatar = IdenticonAvatar.newAvatarBuilder().apply {
-            avatarBaseParam?.size?.let(this::size)
-            avatarBaseParam?.margin?.let(this::margin)
-            avatarBaseParam?.padding?.let(this::padding)
+            avatarBaseParam?.size?.let(::size)
+            avatarBaseParam?.margin?.let(::margin)
+            avatarBaseParam?.padding?.let(::padding)
            if (avatarBaseParam != null && !avatarBaseParam.colors.isNullOrEmpty()) {
                color(decodeColor(avatarBaseParam.colors!!.random()))
            }
@@ -114,9 +114,9 @@ class AvatarServiceImpl : IAvatarService {
    override fun github(avatarGitHubParam: AvatarGitHubParam?): ByteArray {
        val avatar = (avatarGitHubParam?.let { GitHubAvatar.newAvatarBuilder(it.elementSize, it.precision) }
            ?: let { GitHubAvatar.newAvatarBuilder(400, 5) }).apply {
-            avatarGitHubParam?.size?.let(this::size)
-            avatarGitHubParam?.margin?.let(this::margin)
-            avatarGitHubParam?.padding?.let(this::padding)
+            avatarGitHubParam?.size?.let(::size)
+            avatarGitHubParam?.margin?.let(::margin)
+            avatarGitHubParam?.padding?.let(::padding)
            if (avatarGitHubParam != null && !avatarGitHubParam.colors.isNullOrEmpty()) {
                color(decodeColor(avatarGitHubParam.colors!!.random()))
            }
--- a/src/main/kotlin/top/fatweb/oxygen/api/service/permission/impl/AuthenticationServiceImpl.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/service/permission/impl/AuthenticationServiceImpl.kt
@@ -152,7 +152,7 @@ class AuthenticationServiceImpl(
        verifyCaptcha(forgetParam.captchaCode!!)

        val user = userService.getUserWithPowerByAccount(forgetParam.email!!)
-        user ?: let { throw UserNotFoundException() }
+        user ?: throw UserNotFoundException()

        user.forget?.let {
            if (LocalDateTime.ofInstant(Instant.ofEpochMilli(it.split("-").first().toLong()), ZoneOffset.UTC)
@@ -210,21 +210,19 @@ class AuthenticationServiceImpl(

    @EventLogRecord(EventLog.Event.LOGOUT)
    override fun logout(token: String): Boolean {
-        val loginUser = WebUtil.getLoginUser() ?: let { throw TokenHasExpiredException() }
+        val loginUser = WebUtil.getLoginUser() ?: throw TokenHasExpiredException()

        return redisUtil.delObject("${SecurityProperties.jwtIssuer}_login_${loginUser.user.id}:" + token)
    }

    override fun renewToken(token: String): TokenVo {
-        val loginUser = WebUtil.getLoginUser() ?: let { throw TokenHasExpiredException() }
+        val loginUser = WebUtil.getLoginUser() ?: throw TokenHasExpiredException()

        val oldRedisKey = "${SecurityProperties.jwtIssuer}_login_${loginUser.user.id}:" + token
        redisUtil.delObject(oldRedisKey)
        val jwt = JwtUtil.createJwt(WebUtil.getLoginUserId().toString())

-        jwt ?: let {
-            throw RuntimeException("Login failed")
-        }
+        jwt ?: throw RuntimeException("Login failed")

        val redisKey = "${SecurityProperties.jwtIssuer}_login_${loginUser.user.id}:" + jwt
        redisUtil.setObject(
@@ -308,9 +306,7 @@ class AuthenticationServiceImpl(
        val usernamePasswordAuthenticationToken =
            UsernamePasswordAuthenticationToken(account, password)
        val authentication = authenticationManager.authenticate(usernamePasswordAuthenticationToken)
-        authentication ?: let {
-            throw RuntimeException("Login failed")
-        }
+        authentication ?: throw RuntimeException("Login failed")

        val loginUser = authentication.principal as LoginUser
        loginUser.user.password = ""
@@ -326,9 +322,7 @@ class AuthenticationServiceImpl(
        val userId = loginUser.user.id.toString()
        val jwt = JwtUtil.createJwt(userId)

-        jwt ?: let {
-            throw RuntimeException("Login failed")
-        }
+        jwt ?: throw RuntimeException("Login failed")

        val redisKey = "${SecurityProperties.jwtIssuer}_login_${userId}:" + jwt
        redisUtil.setObject(redisKey, loginUser, SecurityProperties.redisTtl, SecurityProperties.redisTtlUnit)
--- a/src/main/kotlin/top/fatweb/oxygen/api/service/permission/impl/RoleServiceImpl.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/service/permission/impl/RoleServiceImpl.kt
@@ -68,7 +68,7 @@ class RoleServiceImpl(

    @Transactional
    override fun add(roleAddParam: RoleAddParam): RoleVo {
-        val fullPowerIds = roleAddParam.powerIds?.let(this::getFullPowerIds)
+        val fullPowerIds = roleAddParam.powerIds?.let(::getFullPowerIds)

        val role = RoleConverter.roleAddParamToRole(roleAddParam)
        if (baseMapper.insert(role) != 1) {
@@ -90,7 +90,7 @@ class RoleServiceImpl(

    @Transactional
    override fun update(roleUpdateParam: RoleUpdateParam): RoleVo {
-        val fullPowerIds = roleUpdateParam.powerIds?.let(this::getFullPowerIds)
+        val fullPowerIds = roleUpdateParam.powerIds?.let(::getFullPowerIds)

        val role = RoleConverter.roleUpdateParamToRole(roleUpdateParam)

--- a/src/main/kotlin/top/fatweb/oxygen/api/service/permission/impl/UserDetailsServiceImpl.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/service/permission/impl/UserDetailsServiceImpl.kt
@@ -18,7 +18,7 @@ import top.fatweb.oxygen.api.service.permission.IUserService
 class UserDetailsServiceImpl(val userService: IUserService) : UserDetailsService {
    override fun loadUserByUsername(account: String): UserDetails {
        val user = userService.getUserWithPowerByAccount(account)
-        user ?: let { throw Exception("Username not found") }
+        user ?: throw Exception("Username not found")

        return LoginUser(user)
    }
--- a/src/main/kotlin/top/fatweb/oxygen/api/service/permission/impl/UserServiceImpl.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/service/permission/impl/UserServiceImpl.kt
@@ -68,7 +68,7 @@ class UserServiceImpl(
 ) : ServiceImpl<UserMapper, User>(), IUserService {
    override fun getUserWithPowerByAccount(account: String): User? {
        val user = baseMapper.selectOneWithPowerInfoByAccount(account)
-        user ?: let { return null }
+        user ?: return null

        if (user.id == 0L) {
            user.modules = moduleService.list()
@@ -81,7 +81,7 @@ class UserServiceImpl(
    }

    override fun getInfo(): UserWithPowerInfoVo =
-        WebUtil.getLoginUsername()?.let(this::getUserWithPowerByAccount)?.let(UserConverter::userToUserWithPowerInfoVo)
+        WebUtil.getLoginUsername()?.let(::getUserWithPowerByAccount)?.let(UserConverter::userToUserWithPowerInfoVo)
            ?: throw UserNotFoundException()

    override fun getOne(id: Long): UserWithRoleInfoVo =
@@ -260,9 +260,7 @@ class UserServiceImpl(
            }

            userUpdatePasswordParam.id?.let { WebUtil.offlineUser(redisUtil, it) }
-        } ?: let {
-            throw NoRecordFoundException()
-        }
+        } ?: throw NoRecordFoundException()
    }

    @Transactional
--- a/src/main/kotlin/top/fatweb/oxygen/api/service/system/impl/SensitiveWordServiceImpl.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/service/system/impl/SensitiveWordServiceImpl.kt
@@ -49,7 +49,7 @@ class SensitiveWordServiceImpl : ServiceImpl<SensitiveWordMapper, SensitiveWord>
    @Transactional(propagation = Propagation.REQUIRES_NEW)
    override fun checkSensitiveWord(str: String) {
        this.list(KtQueryWrapper(SensitiveWord()).eq(SensitiveWord::enable, 1)).map(SensitiveWord::word).forEach {
-            it ?: let { return@forEach }
+            it ?: return@forEach

            try {
                if (Regex(it, RegexOption.IGNORE_CASE).matches(str)) {
--- a/src/main/kotlin/top/fatweb/oxygen/api/util/ApiResponseMappingHandlerMapping.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/util/ApiResponseMappingHandlerMapping.kt
@@ -15,7 +15,7 @@ class ApiResponseMappingHandlerMapping : RequestMappingHandlerMapping() {

    private fun createCondition(clazz: Class<*>): RequestCondition<ApiVersionCondition>? {
        val apiController = clazz.getAnnotation(ApiController::class.java)
-        apiController ?: let { return null }
+        apiController ?: return null

        return ApiVersionCondition(apiController.version)
    }
--- a/src/main/kotlin/top/fatweb/oxygen/api/util/StrUtil.kt
+++ b/src/main/kotlin/top/fatweb/oxygen/api/util/StrUtil.kt
@@ -19,7 +19,7 @@ object StrUtil {
     * @since 1.0.0
     */
    fun upperToUnderLetter(str: String?): String {
-        str ?: let { return "" }
+        str ?: return ""

        return Regex("[A-Z]").replace(str) { matchResult -> "_${matchResult.value.lowercase()}" }
    }
@@ -33,7 +33,7 @@ object StrUtil {
     * @since 1.0.0
     */
    fun underToUpperLetter(str: String?): String {
-        str ?: let { return "" }
+        str ?: return ""

        return Regex("_[a-z]").replace(str) { matchResult -> matchResult.value.removePrefix("_").uppercase() }
    }