replace `is_ancestor?` with `ancestor?`

app/models/deployment.rb

@@ -49,7 +49,7 @@ class Deployment < ActiveRecord::Base
     # created before then could have a `sha` referring to a commit that no
     # longer exists in the repository, so just ignore those.
     begin
-      project.repository.is_ancestor?(commit.id, sha)
+      project.repository.ancestor?(commit.id, sha)
     rescue Rugged::OdbError
       false
     end

app/models/repository.rb

@@ -944,7 +944,7 @@ class Repository
     if branch_commit
       same_head = branch_commit.id == root_ref_commit.id
-      !same_head && is_ancestor?(branch_commit.id, root_ref_commit.id)
+      !same_head && ancestor?(branch_commit.id, root_ref_commit.id)
     else
       nil
     end
@@ -958,12 +958,12 @@ class Repository
     nil
   end
-  def is_ancestor?(ancestor_id, descendant_id)
+  def ancestor?(ancestor_id, descendant_id)
     return false if ancestor_id.nil? || descendant_id.nil?
     Gitlab::GitalyClient.migrate(:is_ancestor) do |is_enabled|
       if is_enabled
-        raw_repository.is_ancestor?(ancestor_id, descendant_id)
+        raw_repository.ancestor?(ancestor_id, descendant_id)
       else
         rugged_is_ancestor?(ancestor_id, descendant_id)
       end

lib/gitlab/git/repository.rb

@@ -439,7 +439,7 @@ module Gitlab
       end
       # Returns true is +from+ is direct ancestor to +to+, otherwise false
-      def is_ancestor?(from, to)
+      def ancestor?(from, to)
         gitaly_commit_client.is_ancestor(from, to)
       end

spec/models/repository_spec.rb

@@ -2036,23 +2036,23 @@ describe Repository, models: true do
     end
   end
-  describe '#is_ancestor?' do
+  describe '#ancestor?' do
     let(:commit) { repository.commit }
     let(:ancestor) { commit.parents.first }
     context 'with Gitaly enabled' do
       it 'it is an ancestor' do
-        expect(repository.is_ancestor?(ancestor.id, commit.id)).to eq(true)
+        expect(repository.ancestor?(ancestor.id, commit.id)).to eq(true)
       end
       it 'it is not an ancestor' do
-        expect(repository.is_ancestor?(commit.id, ancestor.id)).to eq(false)
+        expect(repository.ancestor?(commit.id, ancestor.id)).to eq(false)
       end
       it 'returns false on nil-values' do
-        expect(repository.is_ancestor?(nil, commit.id)).to eq(false)
-        expect(repository.is_ancestor?(ancestor.id, nil)).to eq(false)
-        expect(repository.is_ancestor?(nil, nil)).to eq(false)
+        expect(repository.ancestor?(nil, commit.id)).to eq(false)
+        expect(repository.ancestor?(ancestor.id, nil)).to eq(false)
+        expect(repository.ancestor?(nil, nil)).to eq(false)
       end
     end
@@ -2063,17 +2063,17 @@ describe Repository, models: true do
       end
       it 'it is an ancestor' do
-        expect(repository.is_ancestor?(ancestor.id, commit.id)).to eq(true)
+        expect(repository.ancestor?(ancestor.id, commit.id)).to eq(true)
       end
       it 'it is not an ancestor' do
-        expect(repository.is_ancestor?(commit.id, ancestor.id)).to eq(false)
+        expect(repository.ancestor?(commit.id, ancestor.id)).to eq(false)
       end
       it 'returns false on nil-values' do
-        expect(repository.is_ancestor?(nil, commit.id)).to eq(false)
-        expect(repository.is_ancestor?(ancestor.id, nil)).to eq(false)
-        expect(repository.is_ancestor?(nil, nil)).to eq(false)
+        expect(repository.ancestor?(nil, commit.id)).to eq(false)
+        expect(repository.ancestor?(ancestor.id, nil)).to eq(false)
+        expect(repository.ancestor?(nil, nil)).to eq(false)
       end
     end
   end