Module: FlossFunding::UnderBar

Defined in:
lib/floss_funding/under_bar.rb

Overview

Utilities to convert Ruby namespaces to safe, uppercased, underscore forms
for environment variable names. Protects against malicious or invalid class
names via conservative character rules.

See also: https://github.com/galtzo-floss/shields-badge/blob/main/lib/shields/badge.rb

Constant Summary collapse

SAFE_TO_UNDERSCORE =

Allowed characters for a single namespace segment. Max length 256 to avoid abuse.

Returns:

  • (Regexp) 
/\A[\p{UPPERCASE-LETTER}\p{LOWERCASE-LETTER}\p{DECIMAL-NUMBER}]{1,256}\Z/
SUBBER_UNDER =

Pattern to insert underscores before capital letters.

Returns:

  • (Regexp) 
/(\p{UPPERCASE-LETTER})/
INITIAL_UNDERSCORE =

Pattern for a leading underscore to be removed after transformation.

Returns:

  • (Regexp) 
/^_/

Class Method Summary collapse

Class Method Details

._cache ⇒ Object

Internal memoization cache for env var names



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# File 'lib/floss_funding/under_bar.rb', line 22

def _cache
  @cache ||= {}
end

.env_variable_name(namespace) ⇒ String

Builds an uppercased ENV variable name from a Ruby namespace.

Parameters:

Returns:

  • (String) —

    the resulting ENV variable name

Raises:



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# File 'lib/floss_funding/under_bar.rb', line 35

def env_variable_name(namespace)
  return namespace.env_var_name if namespace.respond_to?(:env_var_name)

  raise FlossFunding::Error, "namespace must be a String, but is #{namespace.class}" unless namespace.is_a?(String)

  cached = _cache[namespace]
  return cached if cached

  name_parts = namespace.split("::")
  env_name = name_parts.map { |np| to_under_bar(np) }.join("__")
  result = "#{::FlossFunding::Constants::DEFAULT_PREFIX}#{env_name}".upcase
  _cache[namespace] = result.freeze
end

.reset_cache! ⇒ Object 



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# File 'lib/floss_funding/under_bar.rb', line 26

def reset_cache!
  @cache = {}
end

.to_under_bar(string) ⇒ String

Converts a single namespace segment to an underscored, uppercased string.

Parameters:

  • string (String) —

    the namespace segment to convert

Returns:

  • (String) —

    an uppercased, underscore-separated representation

Raises:



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# File 'lib/floss_funding/under_bar.rb', line 54

def to_under_bar(string)
  safe = string[SAFE_TO_UNDERSCORE]
  raise FlossFunding::Error, "Invalid! Each part of klass name must match #{SAFE_TO_UNDERSCORE}: #{safe} (#{safe.class}) != #{string[0..255]} (#{string.class})" unless safe == string.to_s

  underscored = safe.gsub(SUBBER_UNDER) { "_#{$1}" }
  shifted_leading_underscore = underscored.sub(INITIAL_UNDERSCORE, "")
  shifted_leading_underscore.upcase
end