config.rb

# Creates classes in Obj-C and Java that contain values from
# config.yaml (which can be overridden by ENV).

# Values are obfuscated. (Untested as to how secure this is,
# but the point is to do better than completely plain
# public api keys visible in builds/plists)

# The key value pairs can be accessed from React Native via:
# NativeModules.AppEnv.XYZ

# Need to change "MyApp" and "myapp" and make path adjustments
# as needed in your project.

# - Joe Noon ([email protected])

require 'yaml'
require 'erb'

config = ENV["CONFIGURATION"]

yaml_filename = File.expand_path("config.yaml", File.dirname(__FILE__))
yaml = YAML::load(ERB.new(IO.read(yaml_filename)).result)

env = {}
yaml.each_pair do |k,opts|
  env[k] = (ENV[k] || opts[config]).to_s
  if env[k] == "!"
    raise "MISSING ENV['#{k}']"
  end
end

env_filename = File.expand_path("ios/MyApp/AppEnv.h", File.dirname(__FILE__))

output = %Q{
@import UIKit;
#import "RCTBridgeModule.h"
@interface AppEnv : NSObject <RCTBridgeModule>
@property NSTimeInterval timeToParse;
@property NSMutableDictionary *env;
+ (instancetype)sharedInstance;
- (NSDictionary *)constantsToExport;
#{env.keys.map { |k| "- (NSString*)#{k};" }.join("\n")}
@end
}

File.open(env_filename, "w") do |f|
  f.puts output
end

env_filename = File.expand_path("ios/MyApp/AppEnv.m", File.dirname(__FILE__))

env_builders = []
func_builders = []
# each env var is put into a hash with value obfuscated.
# a comment is prepended for the developer with the unobfuscated value, but does not make it into the binary.
env.each_pair do |k,v|
  v_ords = v.to_s.scan(/./).map { |x| x.ord }
  if v_ords.any?
    env_builders  << %Q{    [_env setObject:[self getVal:(const char[])#{v_ords.inspect.sub("[", "{").sub("]", "}")} length:#{v_ords.size}] forKey:@#{k.inspect}]; }
  else
    env_builders  << %Q{    [_env setObject:@"" forKey:@#{k.inspect}]; }
  end
  func_builders << "// #{k} #=> #{v.inspect}"
  func_builders << "- (NSString*)#{k} { return [_env valueForKey:@#{k.inspect}]; }"
end

output = %Q{
#import "RCTBridge.h"
#import "AppEnv.h"
@implementation AppEnv
RCT_EXPORT_MODULE()
@synthesize timeToParse = _timeToParse;
@synthesize env = _env;
@synthesize bridge = _bridge;
RCT_EXPORT_METHOD(reload)
{
    [_bridge reload];
}
+ (instancetype)sharedInstance {
  static AppEnv *_sharedInstance = nil;
  static dispatch_once_t once_token;
  dispatch_once(&once_token, ^{
    _sharedInstance = [AppEnv new];
  });
  return _sharedInstance;
}
- (instancetype)init
{
  if ((self = [super init])) {
    _env = [NSMutableDictionary dictionary];
    NSDate* startTime = [NSDate date];

#{env_builders.join("\n")}
    
    //[_env setObject:[self getVal:(const char[]){ 115, 111, 109, 101, 116, 104, 105, 110, 103, 32, 110, 101, 119, 32, 104, 101, 114, 101, 33 } length:19] forKey:@"something"];
    
    NSDate* endTime = [NSDate date];
    _timeToParse = [endTime timeIntervalSinceDate:startTime];
    NSBundle* mainBundle = [NSBundle mainBundle];
    [_env setObject:[mainBundle bundleIdentifier] forKey:@"bundleIdentifier"];
    [_env setObject:[mainBundle objectForInfoDictionaryKey:@"CFBundleVersion"] forKey:@"longVersion"];
    [_env setObject:[mainBundle objectForInfoDictionaryKey:@"CFBundleShortVersionString"] forKey:@"shortVersion"];
    [_env setObject:UIApplicationOpenSettingsURLString forKey:@"UIApplicationOpenSettingsURLString"];
  }
  return self;
}
- (NSString*)getVal:(const char *)bytes length:(int)length {
  return [[NSString alloc] initWithBytes:bytes length:length encoding:NSUTF8StringEncoding];
}

#{func_builders.join("\n")}

//- (NSString*)something { return [_env valueForKey:@"something"]; }

- (NSDictionary *)constantsToExport { return _env; }
@end
}

File.open(env_filename, "w") do |f|
  f.puts output
end

env_filename = File.expand_path("android/app/src/main/java/com/MyApp/AppEnv.java", File.dirname(__FILE__))

env_builders = []
# each env var is put into a hash with value obfuscated.
# a comment is prepended for the developer with the unobfuscated value, but does not make it into the binary.
env.each_pair do |k,v|
  v_ords = v.to_s.scan(/./).map { |x| x.ord }
  env_builders << %Q{        // #{k}: #{v.inspect}}
  env_builders << %Q{        this.env.put(#{k.inspect}, this.getVal(new byte[]#{v_ords.inspect.sub("[", "{").sub("]", "}")}));}
end

output = %Q{
package com.myapp;
import android.widget.Toast;
import com.facebook.react.bridge.NativeModule;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.bridge.ReactContext;
import com.facebook.react.bridge.ReactContextBaseJavaModule;
import java.util.ArrayList;
import java.util.HashMap;
import com.facebook.react.bridge.ReactMethod;
import java.util.Map;
import com.facebook.react.shell.MainReactPackage;
import java.util.List;
import java.io.UnsupportedEncodingException;

public class AppEnv extends ReactContextBaseJavaModule {
    public Map<String, Object> env = new HashMap<>();;
    public AppEnv(ReactApplicationContext reactContext) {
        super(reactContext);
        this.env.put("packageName", "com.myapp");
        this.env.put("longVersion", "1");
        this.env.put("shortVersion", "1");
#{env_builders.join("\n")}
    }
    @Override
    public String getName() {
        return "AppEnv";
    }
    @Override
    public Map<String, Object> getConstants() {
        return env;
    }
    public String getVal(byte[] bytes) {
        String string = "";
        try
        {
          string = new String(bytes, "UTF8");
        }
        catch( UnsupportedEncodingException e)
        {
        }
        return string;
    }
}

class AppEnvPackage extends MainReactPackage {
    @Override
    public List<NativeModule> createNativeModules(ReactApplicationContext reactContext) {
        List<NativeModule> modules = new ArrayList<>();
        modules.add(new AppEnv(reactContext));
        return modules;
    }
}
}

File.open(env_filename, "w") do |f|
  f.puts output
end

puts "***********************"
puts "*  AppEnv constants   *"
puts "***********************"

env.keys.sort.each do |k|
  puts "#{k}: #{env[k]}"
end

config.yaml

# Example config.yaml use-cases
# Only keys here will make it into AppEnv.
# Env vars for the same keys will override values here.
SENTRY_DSN:
  Debug:
  Release: https://[email protected]/1
APP_GIT_COMMIT:
  Debug:
  Release: # blank, so ENV["APP_GIT_COMMIT"] will be checked when building AppEnv
GOOGLE_TRACKING_ID:
  Debug: UA-1
  Release: UA-2
google_place_key:
  Debug: ABC
  Release: XYZ
graphqlURL:
  Debug: http://localhost:3001/graphql
  Release: https://api.productionurl/graphql