Move 'Search Snippets' Spinach feature to Rspec

This commit moves the `search_snippets.feature` Spinach test to a
Rspec feature, as part of deprecating the Spinach test suite.

- Remove Spinach discover snippets feature and steps
- Remove unused `SharedSearch` module
- Add Rspec feature scenarios

features/snippet_search.feature

-@dashboard
-Feature: Snippet Search
-  Background:
-    Given I sign in as a user
-    And I have public "Personal snippet one" snippet
-    And I have private "Personal snippet private" snippet
-    And I have a public many lined snippet
-
-  Scenario: I should see my public and private snippets
-    When I search for "snippet" in snippet titles
-    Then I should see "Personal snippet one" in results
-    And I should see "Personal snippet private" in results
-
-  Scenario: I should see three surrounding lines on either side of a matching snippet line
-    When I search for "line seven" in snippet contents
-    Then I should see "line four" in results
-    And I should see "line seven" in results
-    And I should see "line ten" in results
-    And I should not see "line three" in results
-    And I should not see "line eleven" in results

features/steps/shared/search.rb

-module SharedSearch
-  include Spinach::DSL
-
-  def search_snippet_contents(query)
-    visit "/search?search=#{URI::encode(query)}&snippets=true&scope=snippet_blobs"
-  end
-
-  def search_snippet_titles(query)
-    visit "/search?search=#{URI::encode(query)}&snippets=true&scope=snippet_titles"
-  end
-end

features/steps/snippet_search.rb

-class Spinach::Features::SnippetSearch < Spinach::FeatureSteps
-  include SharedAuthentication
-  include SharedPaths
-  include SharedSnippet
-  include SharedUser
-  include SharedSearch
-
-  step 'I search for "snippet" in snippet titles' do
-    search_snippet_titles 'snippet'
-  end
-
-  step 'I search for "snippet private" in snippet titles' do
-    search_snippet_titles 'snippet private'
-  end
-
-  step 'I search for "line seven" in snippet contents' do
-    search_snippet_contents 'line seven'
-  end
-
-  step 'I should see "line seven" in results' do
-    expect(page).to have_content 'line seven'
-  end
-
-  step 'I should see "line four" in results' do
-    expect(page).to have_content 'line four'
-  end
-
-  step 'I should see "line ten" in results' do
-    expect(page).to have_content 'line ten'
-  end
-
-  step 'I should not see "line eleven" in results' do
-    expect(page).not_to have_content 'line eleven'
-  end
-
-  step 'I should not see "line three" in results' do
-    expect(page).not_to have_content 'line three'
-  end
-
-  step 'I should see "Personal snippet one" in results' do
-    expect(page).to have_content 'Personal snippet one'
-  end
-
-  step 'I should see "Personal snippet private" in results' do
-    expect(page).to have_content 'Personal snippet private'
-  end
-
-  step 'I should not see "Personal snippet one" in results' do
-    expect(page).not_to have_content 'Personal snippet one'
-  end
-
-  step 'I should not see "Personal snippet private" in results' do
-    expect(page).not_to have_content 'Personal snippet private'
-  end
-end

spec/features/snippets/search_snippets_spec.rb

+require 'rails_helper'
+
+feature 'Search Snippets', feature: true do
+  scenario 'User searches for snippets by title' do
+    public_snippet = create(:personal_snippet, :public, title: 'Beginning and Middle')
+    private_snippet = create(:personal_snippet, :private, title: 'Middle and End')
+
+    login_as private_snippet.author
+    visit dashboard_snippets_path
+
+    page.within '.search' do
+      fill_in 'search', with: 'Middle'
+      click_button 'Go'
+    end
+
+    click_link 'Titles and Filenames'
+
+    expect(page).to have_link(public_snippet.title)
+    expect(page).to have_link(private_snippet.title)
+  end
+
+  scenario 'User searches for snippet contents' do
+    create(:personal_snippet,
+           :public,
+           title: 'Many lined snippet',
+           content: <<-CONTENT.strip_heredoc
+             |line one
+             |line two
+             |line three
+             |line four
+             |line five
+             |line six
+             |line seven
+             |line eight
+             |line nine
+             |line ten
+             |line eleven
+             |line twelve
+             |line thirteen
+             |line fourteen
+           CONTENT
+          )
+
+    login_as create(:user)
+    visit dashboard_snippets_path
+
+    page.within '.search' do
+      fill_in 'search', with: 'line seven'
+      click_button 'Go'
+    end
+
+    expect(page).to have_content('line seven')
+
+    # 3 lines before the matched line should be visible
+    expect(page).to have_content('line six')
+    expect(page).to have_content('line five')
+    expect(page).to have_content('line four')
+    expect(page).not_to have_content('line three')
+
+    # 3 lines after the matched line should be visible
+    expect(page).to have_content('line eight')
+    expect(page).to have_content('line nine')
+    expect(page).to have_content('line ten')
+    expect(page).not_to have_content('line eleven')
+  end
+end