Check whether a PR is mergeable.

Author: nat-henderson

README.md

@@ -58,6 +58,12 @@ resource_types:
 * `disable_forks`: *Optional*, default false. If set to `true`, it will filter
   out pull requests that were created via users that forked from your repo.
 
+* `only_mergeable`: *Optional*, default false. If set to `true`, it will filter
+  out pull requests that are not mergeable.  A pull request is mergeable if
+  - It has no merge conflicts.
+  - The current user has push permissions to the base repository.
+  - It has at least one review and has been Approved.
+
 * `label`: *Optional.* If set to a string it will only return pull requests that have been
 marked with that specific label. It is case insensitive.
 

assets/lib/filters/mergeable.rb

@@ -0,0 +1,16 @@
+module Filters
+  class Mergeable 
+    def initialize(pull_requests:, input: Input.instance)
+      @pull_requests = pull_requests
+      @input = input
+    end
+
+    def pull_requests
+      if @input.source.only_mergeable
+        @memoized ||= @pull_requests.delete_if {|x| !x.mergeable? }
+      else
+        @pull_requests
+      end
+    end
+  end
+end

assets/lib/pull_request.rb

@@ -16,6 +16,12 @@ def from_fork?
     base_repo != head_repo
   end
 
+  def mergeable?
+      (@pr['mergeable'] &&
+       @pr['base']['repo']['permissions']['push'] &&
+       Octokit.pull_request_reviews(base_repo, id).any? {|r| r['state'] == 'APPROVED'})
+  end
+
   def equals?(id:, sha:)
     [self.sha, self.id.to_s] == [sha, id.to_s]
   end

assets/lib/repository.rb

@@ -5,11 +5,12 @@
 require_relative 'filters/label'
 require_relative 'filters/path'
 require_relative 'filters/ci_skip'
+require_relative 'filters/mergeable'
 
 class Repository
   attr_reader :name
 
-  def initialize(name:, input: Input.instance, filters: [Filters::All, Filters::Path, Filters::Fork, Filters::Label, Filters::CISkip])
+  def initialize(name:, input: Input.instance, filters: [Filters::All, Filters::Path, Filters::Fork, Filters::Label, Filters::CISkip, Filters::Mergeable])
     @filters = filters
     @name    = name
     @input   = input