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Diffstat (limited to 'lib/extracts_ref.rb')
| -rw-r--r-- | lib/extracts_ref.rb | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/lib/extracts_ref.rb b/lib/extracts_ref.rb new file mode 100644 index 00000000000..346ed6b6f60 --- /dev/null +++ b/lib/extracts_ref.rb @@ -0,0 +1,128 @@ +# frozen_string_literal: true + +# Module providing methods for dealing with separating a tree-ish string and a +# file path string when combined in a request parameter +# Can be extended for different types of repository object, e.g. Project or Snippet +module ExtractsRef + InvalidPathError = Class.new(StandardError) + + # Given a string containing both a Git tree-ish, such as a branch or tag, and + # a filesystem path joined by forward slashes, attempts to separate the two. + # + # Expects a repository_container method that returns the active repository object. This is + # used to check the input against a list of valid repository refs. + # + # Examples + # + # # No repository_container available + # extract_ref('master') + # # => ['', ''] + # + # extract_ref('master') + # # => ['master', ''] + # + # extract_ref("f4b14494ef6abf3d144c28e4af0c20143383e062/CHANGELOG") + # # => ['f4b14494ef6abf3d144c28e4af0c20143383e062', 'CHANGELOG'] + # + # extract_ref("v2.0.0/README.md") + # # => ['v2.0.0', 'README.md'] + # + # extract_ref('master/app/models/project.rb') + # # => ['master', 'app/models/project.rb'] + # + # extract_ref('issues/1234/app/models/project.rb') + # # => ['issues/1234', 'app/models/project.rb'] + # + # # Given an invalid branch, we fall back to just splitting on the first slash + # extract_ref('non/existent/branch/README.md') + # # => ['non', 'existent/branch/README.md'] + # + # Returns an Array where the first value is the tree-ish and the second is the + # path + def extract_ref(id) + pair = ['', ''] + + return pair unless repository_container + + if id =~ /^(\h{40})(.+)/ + # If the ref appears to be a SHA, we're done, just split the string + pair = $~.captures + else + # Otherwise, attempt to detect the ref using a list of the repository_container's + # branches and tags + + # Append a trailing slash if we only get a ref and no file path + unless id.ends_with?('/') + id = [id, '/'].join + end + + valid_refs = ref_names.select { |v| id.start_with?("#{v}/") } + + if valid_refs.empty? + # No exact ref match, so just try our best + pair = id.match(%r{([^/]+)(.*)}).captures + else + # There is a distinct possibility that multiple refs prefix the ID. + # Use the longest match to maximize the chance that we have the + # right ref. + best_match = valid_refs.max_by(&:length) + # Partition the string into the ref and the path, ignoring the empty first value + pair = id.partition(best_match)[1..-1] + end + end + + pair[0] = pair[0].strip + + # Remove ending slashes from path + pair[1].gsub!(%r{^/|/$}, '') + + pair + end + + # Assigns common instance variables for views working with Git tree-ish objects + # + # Assignments are: + # + # - @id - A string representing the joined ref and path + # - @ref - A string representing the ref (e.g., the branch, tag, or commit SHA) + # - @path - A string representing the filesystem path + # - @commit - A Commit representing the commit from the given ref + # + # If the :id parameter appears to be requesting a specific response format, + # that will be handled as well. + # + # rubocop:disable Gitlab/ModuleWithInstanceVariables + def assign_ref_vars + @id = get_id + @ref, @path = extract_ref(@id) + @repo = repository_container.repository + + raise InvalidPathError if @ref.match?(/\s/) + + @commit = @repo.commit(@ref) + end + # rubocop:enable Gitlab/ModuleWithInstanceVariables + + def tree + @tree ||= @repo.tree(@commit.id, @path) # rubocop:disable Gitlab/ModuleWithInstanceVariables + end + + private + + # overridden in subclasses, do not remove + def get_id + id = [params[:id] || params[:ref]] + id << "/" + params[:path] unless params[:path].blank? + id.join + end + + def ref_names + return [] unless repository_container + + @ref_names ||= repository_container.repository.ref_names # rubocop:disable Gitlab/ModuleWithInstanceVariables + end + + def repository_container + raise NotImplementedError + end +end |