[BUG] Generated Ruby client may contains unexpected interpolation when using pattern

Created by: autopp

Bug Report Checklist

Have you provided a full/minimal spec to reproduce the issue?
Have you validated the input using an OpenAPI validator (example)?
What's the version of OpenAPI Generator used?
Have you search for related issues/PRs?
What's the actual output vs expected output?
[Optional] Bounty to sponsor the fix (example)

Description

When using pattern, the generated Ruby client code may contain an unexpected interpolation.

openapi-generator version

$ java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar version
4.0.0-SNAPSHOT

$ git log --oneline -n 1
aa24f07433 (HEAD -> master, origin/master, origin/HEAD) [TypescriptAngular] gets package npm version from API specification (#2019)

OpenAPI declaration file content or url

See: https://gist.github.com/autopp/925901844b9c973fd3c86d06ea95c03a#file-swagger-yml

The point to notice in this example is that #{...} is included in the pattern.

Command line used for generation

$ java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate --skip-validate-spec -g ruby -o /tmp/gem -i 'https://gist.githubusercontent.com/autopp/925901844b9c973fd3c86d06ea95c03a/raw/df474dc0331ee167d337a2cc7aadc49afdd7ee03/swagger.yml'

Steps to reproduce

Run the above command to generate client code for Ruby.

lib/openapi_client/api/default_api.rb contains unexpected interpolation

def foo_get_with_http_info(opts = {})
  if @api_client.config.debugging
    @api_client.config.logger.debug 'Calling API: DefaultApi.foo_get ...'
  end
  if @api_client.config.client_side_validation && !opts[:'x'].nil? && opts[:'x'] !~ Regexp.new(/^injected code: #{injected.code}$/)
    fail ArgumentError, "invalid value for 'opts[:\"x\"]' when calling DefaultApi.foo_get, must conform to the pattern /^injected code: #{injected.code}$/."
  end

In this example, injected.code is executed when request to GET /foo (And error may occur).

Related issues/PRs

N/A

Suggest a fix

Curretly, RubyClientCodegen dose not override escapeText. Should not this be overridden to accommodate Ruby's string literal characteristics?