support paths and ignore_paths for #42

Author: JT Archie

README.md

@@ -65,6 +65,12 @@ were created via users that forked from your repo.
 
 * `password`: *Optional.* Password for HTTP(S) auth when pulling/pushing.
 
+* `paths`: *Optional.* If specified (as a list of glob patterns), only changes
+  to the specified files will yield new versions from `check`.
+
+* `ignore_paths`: *Optional.* The inverse of `paths`; changes to the specified
+  files are ignored.
+
 * `skip_ssl_verification`: *Optional.* Skips git ssl verification by exporting
   `GIT_SSL_NO_VERIFY=true`.
 

assets/lib/filters/path.rb

@@ -0,0 +1,36 @@
+require_relative '../input'
+
+module Filters
+  class Path
+    def initialize(pull_requests:, input: Input.instance)
+      @pull_requests = pull_requests
+      @input = input
+    end
+
+    def pull_requests
+      paths        = @input.source.paths || []
+      ignore_paths = @input.source.ignore_paths || []
+
+      return @pull_requests if paths.empty? && ignore_paths.empty?
+
+      @memoized ||= @pull_requests.select do |pr|
+        files = Octokit.pull_request_files(@input.source.repo, pr.id)
+        unless paths.empty?
+          files.select! do |file|
+            paths.find do |path|
+              File.fnmatch?(path, file['filename'])
+            end
+          end
+        end
+        unless ignore_paths.empty?
+          files.reject! do |file|
+            ignore_paths.find do |path|
+              File.fnmatch?(path, file['filename'])
+            end
+          end
+        end
+        !files.empty?
+      end
+    end
+  end
+end

assets/lib/repository.rb

@@ -1,11 +1,12 @@
 require_relative 'filters/all'
 require_relative 'filters/context'
 require_relative 'filters/fork'
+require_relative 'filters/path'
 
 class Repository
   attr_reader :name
 
-  def initialize(name:, input: Input.instance, filters: [Filters::All, Filters::Fork, Filters::Context])
+  def initialize(name:, input: Input.instance, filters: [Filters::All, Filters::Path, Filters::Fork, Filters::Context])
     @filters = filters
     @name    = name
     @input   = input

spec/filters/path_spec.rb

@@ -0,0 +1,54 @@
+require_relative '../../assets/lib/filters/path'
+require_relative '../../assets/lib/pull_request'
+require 'webmock/rspec'
+
+describe Filters::Path do
+  let(:ignore_pr) do
+    PullRequest.new(pr: { 'number' => 1 })
+  end
+
+  let(:pr) do
+    PullRequest.new(pr: { 'number' => 2 })
+  end
+
+  let(:pull_requests) { [ignore_pr, pr] }
+
+  def stub_json(uri, body)
+    stub_request(:get, uri)
+      .to_return(headers: { 'Content-Type' => 'application/json' }, body: body.to_json)
+  end
+
+  context 'when paths are not specified' do
+    it 'does not filter' do
+      payload = { 'source' => { 'repo' => 'user/repo' } }
+      filter = described_class.new(pull_requests: pull_requests, input: Input.instance(payload: payload))
+
+      expect(filter.pull_requests).to eq pull_requests
+    end
+  end
+
+  context 'when paths are specified' do
+    before do
+      stub_json(%r{https://api.github.com/repos/user/repo/pulls/1/files}, [{ 'filename' => 'test.cpp' }])
+      stub_json(%r{https://api.github.com/repos/user/repo/pulls/2/files}, [{ 'filename' => 'README.md' }])
+    end
+
+    context 'that is an ignore path' do
+      it 'filters out PRs that match that path' do
+        payload = { 'source' => { 'repo' => 'user/repo', 'ignore_paths' => ['README.md'] } }
+        filter = described_class.new(pull_requests: pull_requests, input: Input.instance(payload: payload))
+
+        expect(filter.pull_requests).to eq [ignore_pr]
+      end
+    end
+
+    context 'that is a path' do
+      it 'only return PRs that match that path' do
+        payload = { 'source' => { 'repo' => 'user/repo', 'paths' => ['README.md'] } }
+        filter = described_class.new(pull_requests: pull_requests, input: Input.instance(payload: payload))
+
+        expect(filter.pull_requests).to eq [pr]
+      end
+    end
+  end
+end