Spec out KeywordMute interface. #164.

spec/models/keyword_mute_spec.rb

@@ -1,5 +1,21 @@
 require 'rails_helper'
 
 RSpec.describe KeywordMute, type: :model do
-  pending "add some examples to (or delete) #{__FILE__}"
+  describe '.matches?' do
+    let(:alice)  { Fabricate(:account, username: 'alice').tap(&:save!) }
+    let(:status) { Fabricate(:status, account: alice).tap(&:save!) }
+    let(:keyword_mute) { Fabricate(:keyword_mute, account: alice, keyword: 'take').tap(&:save!) }
+
+    it 'returns true if any keyword in the set matches the status text' do
+      status.update_attribute(:text, 'This is a hot take')
+
+      expect(KeywordMute.where(account: alice).matches?(status.text)).to be_truthy
+    end
+
+    it 'returns false if no keyword in the set matches the status text'
+
+    describe 'matching' do
+      it 'is case-insensitive'
+    end
+  end
 end