• N
    Cache regexps generated from acronym_regex · a822fc51
    Nick LaMuro 提交于
    The Problem
    -----------
    
    The following line from `String#camelize`:
    
      string = string.sub(/^(?:#{inflections.acronym_regex}(?=\b|[A-Z_])|\w)/) { |match| match.downcase }
    
    and the following line from `String#camelize`:
    
      word.gsub!(/(?:(?<=([A-Za-z\d]))|\b)(#{inflections.acronym_regex})(?=\b|[^a-z])/) { "#{$1 && '_'.freeze }#{$2.downcase}" }#{$2.downcase}" }
    
    Both generate the same regexep in the first part of the `.sub`/`.gsub`
    method calls every time the function is called, creating an extra object
    allocation each time.  The value of `acronym_regex` only changes if the
    user decides add an acronym to the current set of inflections and apends
    another string on the the regexp generated here, but beyond that it
    remains relatively static.
    
    This has been around since acronym support was introduced back in 2011
    in PR#1648.
    
    Proposed Solution
    -----------------
    To avoid re-generating these strings every time these methods are
    called, cache the values of these regular expressions in the
    `ActiveSupport::Inflector::Inflections` instance, making it so these
    regular expressions are only generated once, or when the acronym's are
    added to.
    
    Other notable changes is the attr_readers are nodoc'd, as they shouldn't
    really be public APIs for users.  Also, the new method,
    define_acronym_regex_patterns, is the only method in charge of
    manipulating @acronym_regex, and initialize_dup also makes use of that
    new change.
    
    ** Note about fix for non-deterministic actionpack test **
    
    With the introduction of `@acronym_underscore_regex` and
    `@acronym_camelize_regex`, tests that manipulated these for a short
    time, then reset them could caused test failures to happen.  This
    happened because the previous way we reset the `@acronyms` and
    `@acronym_regex` was the set them using #instance_variable_set, which
    wouldn't run the #define_acronym_regex_patterns method.
    
    This has now been introduced into the actionpack tests to avoid this
    failure.
    a822fc51
request_test.rb 47.4 KB