nestlogged/src/reflected.ts

import {RouteParamtypes} from '@nestjs/common/enums/route-paramtypes.enum';
import {assignMetadata, ParamData, PipeTransform, RouteParamMetadata, Type} from "@nestjs/common";
import {isNil, isString} from "@nestjs/common/utils/shared.utils";

const ROUTE_ARGS_METADATA = '__routeArguments__';

function createRouteParamDecorator(paramtype: RouteParamtypes) {
  return (data?: ParamData): ParameterDecorator =>
    (target, key, index) => {
      const args =
        Reflect.getMetadata(ROUTE_ARGS_METADATA, target.constructor, key) || {};
      Reflect.defineMetadata(
        ROUTE_ARGS_METADATA,
        assignMetadata<RouteParamtypes, Record<number, RouteParamMetadata>>(
          args,
          paramtype,
          index,
          data,
        ),
        target.constructor,
        key,
      );
    };
}

const createPipesRouteParamDecorator =
  (paramtype: RouteParamtypes) =>
  (
    data?: any,
    ...pipes: (Type<PipeTransform> | PipeTransform)[]
  ): ParameterDecorator =>
  (target, key, index) => {
    const args =
      Reflect.getMetadata(ROUTE_ARGS_METADATA, target.constructor, key) || {};
    const hasParamData = isNil(data) || isString(data);
    const paramData = hasParamData ? data : undefined;
    const paramPipes = hasParamData ? pipes : [data, ...pipes];

    Reflect.defineMetadata(
      ROUTE_ARGS_METADATA,
      assignMetadata(args, paramtype, index, paramData, ...paramPipes),
      target.constructor,
      key,
    );
  };

export type Path = string | string[];
export type Paths = Path[];

export interface IncludeExcludePath {
  includePath?: Paths;
  excludePath?: Paths;
}

export interface LoggedParamReflectData {
  name: string;
  index: number;
  include?: string[];
  exclude?: string[];
}

export interface ScopeKeyReflectData {
  name: string;
  index: number;
  path?: string[];
  priority?: number;
}

export interface ReturnsReflectData {
  name: string;
  path: string;
}

export const scopedLogger = Symbol("nlogdec-scopedLogger");
export const loggedParam = Symbol("nlogdec-loggedParam");
export const returns = Symbol("nlogdec-returns");

export const nestLoggedMetadata = Symbol("nlogdec-metadata");

export function InjectLogger(
  target: any,
  propertyKey: string | symbol,
  parameterIndex: number
) {
  Reflect.defineMetadata(scopedLogger, parameterIndex, target, propertyKey);
}

type ParameterDecoratorType = (target: any, propertyKey: string | symbol, parameterIndex: number) => void

function createLoggedFunctionParam(
  name: string,
  options?: IncludeExcludePath
): ParameterDecoratorType {
  return (
    target: any,
    propertyKey: string | symbol,
    parameterIndex: number
  ) => {
    const existingLoggedParams: LoggedParamReflectData[] =
      Reflect.getOwnMetadata(loggedParam, target, propertyKey) || [];

    existingLoggedParams.push({
      name,
      index: parameterIndex,
      // If path is provided in string[] type, convert it to string path because it is used in string type
      include:
        options &&
        options.includePath &&
        options.includePath.map((v) => (Array.isArray(v) ? v.join(".") : v)),
      exclude:
        options &&
        options.excludePath &&
        options.excludePath.map((v) => (Array.isArray(v) ? v.join(".") : v)),
    });

    Reflect.defineMetadata(
      loggedParam,
      existingLoggedParams,
      target,
      propertyKey
    );
  };
}

type LoggedParamReturns = (name: string, options?: IncludeExcludePath) => ParameterDecoratorType;

export const Logged: LoggedParamReturns = (name, options) =>
  createLoggedFunctionParam(name, options)

type Pipe = Type<PipeTransform> | PipeTransform

export function LoggedParam(): LoggedParamReturns;
export function LoggedParam(
  ...pipes: Pipe[]
): LoggedParamReturns;
export function LoggedParam(
  property: string,
  ...pipes: Pipe[]
): LoggedParamReturns;
export function LoggedParam(
  property?: string | Pipe,
  ...pipes: Pipe[]
): LoggedParamReturns {
  return (name, options) => {
    return (target, propertyKey, parameterIndex) => {
      createPipesRouteParamDecorator(RouteParamtypes.PARAM)(
        property,
        ...pipes,
      )(
        target,
        propertyKey,
        parameterIndex,
      );
      createLoggedFunctionParam(name, options)(
        target,
        propertyKey,
        parameterIndex,
      )
    }
  }
}

export function LoggedQuery(): LoggedParamReturns;
export function LoggedQuery(
  ...pipes: Pipe[]
): LoggedParamReturns;
export function LoggedQuery(
  property: string,
  ...pipes: Pipe[]
): LoggedParamReturns;
export function LoggedQuery(
  property?: string | Pipe,
  ...pipes: Pipe[]
): LoggedParamReturns {
  return (name, options) => {
    return (target, propertyKey, parameterIndex) => {
      createPipesRouteParamDecorator(RouteParamtypes.QUERY)(
        property, ...pipes
      )(
        target, propertyKey, parameterIndex,
      );

      createLoggedFunctionParam(name, options)(
        target, propertyKey, parameterIndex,
      );
    }
  }
}

export function LoggedBody(): LoggedParamReturns;
export function LoggedBody(
  ...pipes: Pipe[]
): LoggedParamReturns;
export function LoggedBody(
  property: string,
  ...pipes: Pipe[]
): LoggedParamReturns;
export function LoggedBody(
  property?: string | Pipe,
  ...pipes: Pipe[]
): LoggedParamReturns {
  return (name, options) => {
    return (target, propertyKey, parameterIndex) => {
      createPipesRouteParamDecorator(RouteParamtypes.BODY)(
        property,
        ...pipes,
      )(
        target, propertyKey, parameterIndex
      );

      createLoggedFunctionParam(name, options)(
        target, propertyKey, parameterIndex,
      );
    }
  }
}

export function LoggedHeaders(property?: string): LoggedParamReturns {
  return (name, options) => {
    return (target, propertyKey, parameterIndex) => {
      createRouteParamDecorator(RouteParamtypes.HEADERS)(property)(
        target, propertyKey, parameterIndex,
      );

      createLoggedFunctionParam(name, options)(
        target, propertyKey, parameterIndex,
      )
    }
  }
}

export function Returns<F extends Array<any>, R>(namePaths?: {
  [name: string]: string;
} | string) {
  return (
    _target: any,
    _key: string | symbol,
    descriptor: TypedPropertyDescriptor<(...args: F) => Promise<R> | R>
  ) => {
    Reflect.defineMetadata(
      returns,
      namePaths
        ? typeof namePaths === 'string'
          ? namePaths
          : Object.entries(namePaths).reduce<ReturnsReflectData[]>(
              (prev, curr) => [...prev, { name: curr[0], path: curr[1] }],
              []
            )
        : true,
      descriptor.value
    );
  };
}