_HANDLER is not documented in the README

[yegor256]

After upgrade from 2.0.0 to 3.0.0, I'm getting this:

$ bundle exec aws_lambda_ric main.go
--
Init error when loading handler
{
"errorMessage": "Invalid handler [], must be of form FILENAME.METHOD or FILENAME.CLASS.METHOD where FILENAME corresponds with an existing Ruby source file FILENAME.rb, CLASS is an optional module/class namespace and METHOD is a callable method. If using CLASS, METHOD must be a class-level method.",
"errorType": "Init<ArgumentError>",
"stackTrace": [
"/usr/local/bundle/gems/aws_lambda_ric-3.0.0/lib/aws_lambda_ric/lambda_handler.rb:16:in 'LambdaHandler#initialize'",
"/usr/local/bundle/gems/aws_lambda_ric-3.0.0/lib/aws_lambda_ric.rb:45:in 'Class#new'",
"/usr/local/bundle/gems/aws_lambda_ric-3.0.0/lib/aws_lambda_ric.rb:45:in 'AwsLambdaRIC::LambdaRunner#run'",
"/usr/local/bundle/gems/aws_lambda_ric-3.0.0/lib/aws_lambda_ric.rb:219:in 'AwsLambdaRIC::Bootstrap#bootstrap_handler'",
"/usr/local/bundle/gems/aws_lambda_ric-3.0.0/lib/aws_lambda_ric.rb:201:in 'AwsLambdaRIC::Bootstrap#start'",
"/usr/local/bundle/gems/aws_lambda_ric-3.0.0/bin/aws_lambda_ric:9:in '<top (required)>'",
"/usr/local/bundle/bin/aws_lambda_ric:25:in 'Kernel#load'",
"/usr/local/bundle/bin/aws_lambda_ric:25:in '<top (required)>'",
"/usr/local/lib/ruby/3.4.0/bundler/cli/exec.rb:59:in 'Kernel.load'",
"/usr/local/lib/ruby/3.4.0/bundler/cli/exec.rb:59:in 'Bundler::CLI::Exec#kernel_load'",
"/usr/local/lib/ruby/3.4.0/bundler/cli/exec.rb:23:in 'Bundler::CLI::Exec#run'",
"/usr/local/lib/ruby/3.4.0/bundler/cli.rb:452:in 'Bundler::CLI#exec'",

It seems that in 3.0.0 I should call it like this:

$ _HANDLER=main.go bundle exec aws_lambda_ric

Maybe the README should be updated?

[maxday]

hi @yegor256
Thanks for reaching out!
Can you clarify a bit the situation? It seems that you're using the ruby gem with a go file?
Thanks

[yegor256]

@maxday main.go is not the name of the file, but the coordinates of Ruby method. Here, main is the name of the file (main.rb) and go is the name of the method (go()) in this file. See: https://github.com/aws/aws-lambda-ruby-runtime-interface-client/blob/main/lib/aws_lambda_ric/lambda_handler.rb#L10-L17