Use ILIKE/LIKE for searching snippets

Previously this used a regular LIKE which is case-sensitive on
PostgreSQL. This ensures that for both PostgreSQL and MySQL the
searching is case-insensitive similar to searching for projects.

app/models/snippet.rb

@@ -113,12 +113,32 @@ class Snippet < ActiveRecord::Base
   end
 
   class << self
+    # Searches for snippets with a matching title or file name.
+    #
+    # This method uses ILIKE on PostgreSQL and LIKE on MySQL.
+    #
+    # query - The search query as a String.
+    #
+    # Returns an ActiveRecord::Relation.
     def search(query)
-      where('(title LIKE :query OR file_name LIKE :query)', query: "%#{query}%")
+      t = Snippet.arel_table
+      pattern = "%#{query}%"
+
+      where(t[:title].matches(pattern).or(t[:file_name].matches(pattern)))
     end
 
+    # Searches for snippets with matching content.
+    #
+    # This method uses ILIKE on PostgreSQL and LIKE on MySQL.
+    #
+    # query - The search query as a String.
+    #
+    # Returns an ActiveRecord::Relation.
     def search_code(query)
-      where('(content LIKE :query)', query: "%#{query}%")
+      table   = Snippet.arel_table
+      pattern = "%#{query}%"
+
+      where(table[:content].matches(pattern))
     end
 
     def accessible_to(user)

spec/models/snippet_spec.rb

@@ -59,4 +59,48 @@ describe Snippet, models: true do
       expect(snippet.to_reference(cross)).to eq "#{project.to_reference}$#{snippet.id}"
     end
   end
+
+  describe '.search' do
+    let(:snippet) { create(:snippet) }
+
+    it 'returns snippets with a matching title' do
+      expect(described_class.search(snippet.title)).to eq([snippet])
+    end
+
+    it 'returns snippets with a partially matching title' do
+      expect(described_class.search(snippet.title[0..2])).to eq([snippet])
+    end
+
+    it 'returns snippets with a matching title regardless of the casing' do
+      expect(described_class.search(snippet.title.upcase)).to eq([snippet])
+    end
+
+    it 'returns snippets with a matching file name' do
+      expect(described_class.search(snippet.file_name)).to eq([snippet])
+    end
+
+    it 'returns snippets with a partially matching file name' do
+      expect(described_class.search(snippet.file_name[0..2])).to eq([snippet])
+    end
+
+    it 'returns snippets with a matching file name regardless of the casing' do
+      expect(described_class.search(snippet.file_name.upcase)).to eq([snippet])
+    end
+  end
+
+  describe '#search_code' do
+    let(:snippet) { create(:snippet, content: 'class Foo; end') }
+
+    it 'returns snippets with matching content' do
+      expect(described_class.search_code(snippet.content)).to eq([snippet])
+    end
+
+    it 'returns snippets with partially matching content' do
+      expect(described_class.search_code('class')).to eq([snippet])
+    end
+
+    it 'returns snippets with matching content regardless of the casing' do
+      expect(described_class.search_code('FOO')).to eq([snippet])
+    end
+  end
 end