I18n::Tasks::Scanners::PatternMapper is undefined when loading config file

[smaximov]

I'm talking about the following snippet from the default config file:

## Sometimes, it isn't possible for i18n-tasks to match the key correctly,
## e.g. in case of a relative key defined in a helper method.
## In these cases you can use the built-in PatternMapper to map patterns to keys, e.g.:
#
# <%# I18n::Tasks.add_scanner 'I18n::Tasks::Scanners::PatternMapper',
#       only: %w(*.html.haml *.html.slim),
#       patterns: [['= title\b', '.page_title']] %>
#
# The PatternMapper can also match key literals via a special %{key} interpolation, e.g.:
#
# <%# I18n::Tasks.add_scanner 'I18n::Tasks::Scanners::PatternMapper',

I wanted to map = change_locale_link(%{key}) in slim templates to keys in the form shared.locale.%{key}. Using the examples from the snippet, I have come with the following code:

<%
I18n::Tasks.add_scanner 'I18n::Tasks::Scanners::PatternMapper',
     only: %w(*.slim),
     patterns: [['= change_locale_link[( ]\s*%{key}', 'shared.locale.%{key}']]
%>

This results in the NameError uninitialized constant I18n::Tasks::Scanners::PatternMapper when invoking any i18n-tasks command or running the spec. As a temporal solution, loading the file which contains PatternMapper worked for me:

<%

require 'i18n/tasks/scanners/pattern_mapper'

I18n::Tasks.add_scanner 'I18n::Tasks::Scanners::PatternMapper',
                        only: %w(*.slim),
                        patterns: [['= change_locale_link[( ]\s*%{key}', 'shared.locale.%{key}']]
%>

ruby v2.3.1, i18n-tasks v0.9.5.

[kimroen]

The title of this issue states the name of the constant to be I18n::Tasks::Scanner::PatternMapper, but then everywhere else you say it is I18n::Tasks::Scanners::PatternMapper (Scanner vs Scanners), which is the right one. Could you confirm that the right one is in use in the case where you get an error?

[smaximov]

@kimroen, thanks, the one in the title was a typo (my bad), the right one is I18n::Tasks::Scanners::PatternMapper. I've updated the title.

[jtomaszewski]

Same problem here, I just freshly installed recent i18n-tasks release version.

Quick fix for now - just add <% require('i18n/tasks/scanners/pattern_mapper') %> line to the yml config file.