RCTLog.swift

func RCTLogError(_ message: String, _ file: String=#file, _ line: UInt=#line) {
  RCTSwiftLog.error(message, file: file, line: line)
}

func RCTLogWarn(_ message: String, _ file: String=#file, _ line: UInt=#line) {
  RCTSwiftLog.warn(message, file: file, line: line)
}

func RCTLogInfo(_ message: String, _ file: String=#file, _ line: UInt=#line) {
  RCTSwiftLog.info(message, file: file, line: line)
}

func RCTLog(_ message: String, _ file: String=#file, _ line: UInt=#line) {
  RCTSwiftLog.log(message, file: file, line: line)
}

func RCTLogTrace(_ message: String, _ file: String=#file, _ line: UInt=#line) {
  RCTSwiftLog.trace(message, file: file, line: line)
}

RCTSwiftLog.h

//
//  RCTSwiftLog.h
//
//
//  Created by Jimmy Dee on 4/5/17.
//
//

#import <Foundation/Foundation.h>

@interface RCTSwiftLog : NSObject

+ (void)error:(NSString * _Nonnull)message file:(NSString * _Nonnull)file line:(NSUInteger)line;
+ (void)warn:(NSString * _Nonnull)message file:(NSString * _Nonnull)file line:(NSUInteger)line;
+ (void)info:(NSString * _Nonnull)message file:(NSString * _Nonnull)file line:(NSUInteger)line;
+ (void)log:(NSString * _Nonnull)message file:(NSString * _Nonnull)file line:(NSUInteger)line;
+ (void)trace:(NSString * _Nonnull)message file:(NSString * _Nonnull)file line:(NSUInteger)line;

@end

RCTSwiftLog.m

//
//  RCTSwiftLog.m
//
//
//  Created by Jimmy Dee on 4/5/17.
//
//

#import <React/RCTLog.h>

#import "RCTSwiftLog.h"

@implementation RCTSwiftLog

+ (void)info:(NSString *)message file:(NSString *)file line:(NSUInteger)line
{
  _RCTLogNativeInternal(RCTLogLevelInfo, file.UTF8String, (int)line, @"%@", message);
}

+ (void)warn:(NSString *)message file:(NSString *)file line:(NSUInteger)line
{
  _RCTLogNativeInternal(RCTLogLevelWarning, file.UTF8String, (int)line, @"%@", message);
}

+ (void)error:(NSString *)message file:(NSString *)file line:(NSUInteger)line
{
  _RCTLogNativeInternal(RCTLogLevelError, file.UTF8String, (int)line, @"%@", message);
}

+ (void)log:(NSString *)message file:(NSString *)file line:(NSUInteger)line
{
  _RCTLogNativeInternal(RCTLogLevelInfo, file.UTF8String, (int)line, @"%@", message);
}

+ (void)trace:(NSString *)message file:(NSString *)file line:(NSUInteger)line
{
  _RCTLogNativeInternal(RCTLogLevelTrace, file.UTF8String, (int)line, @"%@", message);
}

@end