Improve tests

spec/lgtm_spec.rb

@@ -2,70 +2,67 @@
 
 require File.expand_path('spec_helper', __dir__)
 
-module Danger
-  describe Danger::DangerLgtm do
-    it 'should be a plugin' do
-      expect(Danger::DangerLgtm.new(nil)).to be_a Danger::Plugin
-    end
+describe Danger::DangerLgtm do
+  def mock(request_url: 'https://lgtm.in/p/sSuI4hm0q',
+           actual_image_url: 'https://example.com/image.jpg')
+    double(
+      :[] => request_url,
+      body: JSON.generate(
+        actualImageUrl: actual_image_url
+      )
+    )
+  end
 
-    #
-    # You should test your custom attributes and methods here
-    #
-    describe 'with Dangerfile' do
-      before do
-        @dangerfile = testing_dangerfile
-        @lgtm = @dangerfile.lgtm
-      end
+  it 'should be a plugin' do
+    expect(Danger::DangerLgtm.new(nil)).to be_a(Danger::Plugin)
+  end
 
-      # Some examples for writing tests
-      # You should replace these with your own.
+  describe '#check_lgtm' do
+    subject { lgtm.check_lgtm(https_image_only: https_image_only, image_url: image_url) }
 
-      it 'lgtm with no violation' do
-        @lgtm.check_lgtm
-        expect(@dangerfile.status_report[:markdowns].length).to eq(1)
-      end
+    let(:dangerfile) { testing_dangerfile }
+    let(:lgtm) { dangerfile.lgtm }
+    let(:https_image_only) { false } # default false
+    let(:image_url) {} # default nil
 
-      it 'lgtm with errors' do
-        allow(@lgtm).to receive(:validate_response).and_raise(::Lgtm::Errors::UnexpectedError)
-
-        @lgtm.check_lgtm
+    shared_examples 'returns correctly message' do
+      it do
+        allow(Net::HTTP).to receive(:start).and_return(mock)
+        is_expected
 
-        expect(@dangerfile.status_report[:markdowns][0].message)
-          .to eq("<h1 align='center'>LGTM</h1>")
+        expect(dangerfile.status_report[:markdowns][0].message)
+          .to match(expected_message)
       end
+    end
 
-      def mock(request_url: 'https://lgtm.in/p/sSuI4hm0q',
-               actual_image_url: 'https://example.com/image.jpg')
-        double(
-          :[] => request_url,
-          body: JSON.generate(
-            actualImageUrl: actual_image_url
-          )
-        )
+    context 'with Dangerfile' do
+      it 'when no violation' do
+        is_expected
+        expect(dangerfile.status_report[:markdowns].length).to eq(1)
       end
 
-      it 'pick random pic from lgtm.in' do
-        allow(Net::HTTP).to receive(:start).and_return(mock)
-
-        @lgtm.check_lgtm
-
-        expect(@dangerfile.status_report[:markdowns][0].message)
-          .to match(%r{https:\/\/example.com\/image.jpg})
+      it 'lgtm with errors' do
+        allow(lgtm).to receive(:validate_response).and_raise(::Lgtm::Errors::UnexpectedError)
+        is_expected
+        expect(dangerfile.status_report[:markdowns][0].message)
+          .to eq("<h1 align='center'>LGTM</h1>")
       end
 
-      it 'pick random pic from lgtm.in with https_image_only option' do
-        allow(Net::HTTP).to receive(:start).and_return(mock)
-
-        @lgtm.check_lgtm https_image_only: true
+      context 'pick random pic from lgtm.in' do
+        let(:expected_message) { %r{https:\/\/example.com\/image.jpg} }
+        it_behaves_like 'returns correctly message'
+      end
 
-        expect(@dangerfile.status_report[:markdowns][0].message)
-          .to match(%r{https:\/\/example.com\/image.jpg})
+      context 'pick random pic from lgtm.in with https_image_only option' do
+        let(:https_image_only) { true }
+        let(:expected_message) { %r{https:\/\/example.com\/image.jpg} }
+        it_behaves_like 'returns correctly message'
       end
 
-      it 'use given url' do
-        @lgtm.check_lgtm image_url: 'http://imgur.com/Irk2wyX.jpg'
-        expect(@dangerfile.status_report[:markdowns][0].message)
-          .to match(%r{http:\/\/imgur\.com\/Irk2wyX\.jpg})
+      context 'use given url' do
+        let(:image_url) { 'http://imgur.com/Irk2wyX.jpg' }
+        let(:expected_message) { %r{http:\/\/imgur\.com\/Irk2wyX\.jpg} }
+        it_behaves_like 'returns correctly message'
       end
     end
   end