Enabling suggestions should not fetch a suggestion if buffer is empty

spec/widgets/enable_spec.rb

@@ -6,16 +6,37 @@ describe 'the `autosuggest-enable` widget' do
   end
 
   it 'enables suggestions and fetches a suggestion' do
-    with_history('echo world', 'echo hello') do
-      session.send_string('echo')
+    with_history('echo hello') do
+      session.send_string('e')
       sleep 1
-      expect(session.content).to eq('echo')
+      expect(session.content).to eq('e')
 
       session.send_keys('C-b')
+      session.send_string('c')
       wait_for { session.content }.to eq('echo hello')
+    end
+  end
 
-      session.send_string(' w')
-      wait_for { session.content }.to eq('echo world')
+  context 'invoked on an empty buffer' do
+    it 'does not fetch a suggestion' do
+      with_history('echo hello') do
+        session.send_keys('C-b')
+        sleep 1
+        expect(session.content).to eq('')
+      end
+    end
+  end
+
+  context 'invoked on a non-empty buffer' do
+    it 'fetches a suggestion' do
+      with_history('echo hello') do
+        session.send_string('e')
+        sleep 1
+        expect(session.content).to eq('e')
+
+        session.send_keys('C-b')
+        wait_for { session.content }.to eq('echo hello')
+      end
     end
   end
 end