Rails 7.1 allows ErrorReporter to handle several error classes

ErrorReporter was added to Rails in version 7.0. It was introduced as a way to provide a more consistent and standardized way to handle errors in the Rails applications.

To use ErrorReporter, you need to call the Rails.error.handle method whenever an error occurs. This method will log the error and notify the appropriate error handlers. You can also use ErrorReporter to raise custom errors.

Before Rails 7.1

Before Rails 7.0, developers had to write their own custom code to handle errors. This was done using the begin..rescue..end block.

# to handle a single error
begin
  code_that_raises_exception
rescue ArgumentError => e
  puts e.message
end   

# to handle multiple errors
exceptions = [ArgumentError, StandarError]

begin
  code_that_raises_argument_error
  code_that_raises_standard_error
rescue *exceptions => e
  puts "Error: #{e.message} occurred."
end

Rails 7 introduced the Rails.error. The handle method would only accept or deal with an error of a particular type.

@post = Post.new(params[:post])

Rails.error.handle(ActiveRecord::Errors) do
  @post.save!
end

If you try to pass multiple error handlers to the above method, it will raise ArgumentError as below:

@post = Post.new(params[:post])

Rails.error.handle(ActiveRecord::Errors, StandardError) do
  @post.save!
end

=> wrong number of arguments (given 2, expected 0..1) (ArgumentError)

In Rails 7.1

Rails 7.1 allows ErrorReporter to handle several error classes.

@post = Post.new(params[:post])

Rails.error.handle(ActiveRecord::Errors, StandardError) do
  @post.save!
end

The example code will run without generating any errors. Any error class not passed to the handle function will not be handled.

Rails.error.handle(IOError, ArgumentError) do
  139 + 'abc' # raises TypeError
end

TypeError is not passed as an argument to the handle function, 139 + 'abc' will not be rescued, and TypeError gets raised.

To know more about this feature, please refer to this PR.