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

114 lines
3.6 KiB
Ruby

# Module providing methods for dealing with separating a tree-ish string and a
# file path string when combined in a request parameter
module ExtractsPath
extend ActiveSupport::Concern
# Raised when given an invalid file path
class InvalidPathError < StandardError; end
included do
if respond_to?(:before_filter)
before_filter :assign_ref_vars, only: [:show]
end
end
# 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 @project instance variable to contain the active project. This is
# used to check the input against a list of valid repository refs.
#
# Examples
#
# # No @project 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('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(input)
pair = ['', '']
return pair unless @project
if input.match(/^([[:alnum:]]{40})(.+)/)
# If the ref appears to be a SHA, we're done, just split the string
pair = $~.captures
else
# Otherwise, attempt to detect the ref using a list of the project's
# branches and tags
# Append a trailing slash if we only get a ref and no file path
id = input
id += '/' unless id.include?('/')
valid_refs = @project.branches + @project.tags
valid_refs.select! { |v| id.start_with?("#{v}/") }
if valid_refs.length != 1
# No exact ref match, so just try our best
pair = id.match(/([^\/]+)(.*)/).captures
else
# Partition the string into the ref and the path, ignoring the empty first value
pair = id.partition(valid_refs.first)[1..-1]
end
end
# Remove leading slash from path
pair[1].gsub!(/^\//, '')
pair
end
# Assigns common instance variables for views working with Git tree-ish objects
#
# Assignments are:
#
# - @id - A string representing the joined ref and path
# - @ref - A string representing the ref (e.g., the branch, tag, or commit SHA)
# - @path - A string representing the filesystem path
# - @commit - A CommitDecorator representing the commit from the given ref
# - @tree - A TreeDecorator representing the tree at the given ref/path
#
# If the :id parameter appears to be requesting a specific response format,
# that will be handled as well.
#
# Automatically renders `not_found!` if a valid tree path could not be
# resolved (e.g., when a user inserts an invalid path or ref).
def assign_ref_vars
# Handle formats embedded in the id
if params[:id].ends_with?('.atom')
params[:id].gsub!(/\.atom$/, '')
request.format = :atom
end
@ref, @path = extract_ref(params[:id])
@id = File.join(@ref, @path)
@commit = CommitDecorator.decorate(@project.commit(@ref))
@tree = Tree.new(@commit.tree, @project, @ref, @path)
@tree = TreeDecorator.new(@tree)
raise InvalidPathError if @tree.invalid?
rescue NoMethodError, InvalidPathError
not_found!
end
end