gitlab-org--gitlab-foss/lib/extracts_ref.rb

128 lines
4 KiB
Ruby

# 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