Fix spelling: non-existant -> non-existent.

lib/capybara/session.rb

@@ -486,7 +486,7 @@ module Capybara
     #   @raise [Capybara::WindowError]     if no window matches given block
     # @overload switch_to_window(window)
     #   @param window [Capybara::Window]   window that should be switched to
-    #   @raise [Capybara::Driver::Base#no_such_window_error] if non-existent (e.g. closed) window was passed
+    #   @raise [Capybara::Driver::Base#no_such_window_error] if nonexistent (e.g. closed) window was passed
     #
     # @return [Capybara::Window]         window that has been switched to
     # @raise [Capybara::ScopeError]        if this method is invoked inside `within` or
@@ -519,7 +519,7 @@ module Capybara
     # @overload within_window(window) { do_something }
     #   @param window [Capybara::Window]       instance of `Capybara::Window` class
     #     that will be switched to
-    #   @raise [driver#no_such_window_error] if unexistent (e.g. closed) window was passed
+    #   @raise [driver#no_such_window_error] if nonexistent (e.g. closed) window was passed
     # @overload within_window(proc_or_lambda) { do_something }
     #   @param lambda [Proc]                  lambda. First window for which lambda
     #     returns a value other than false or nil will be switched to.

lib/capybara/spec/session/has_link_spec.rb

@@ -14,8 +14,8 @@ Capybara::SpecHelper.spec '#has_link?' do
 
   it "should be false if the given link is not on the page" do
     expect(@session).not_to have_link('monkey')
-    expect(@session).not_to have_link('A link', href: '/non-existant-href')
-    expect(@session).not_to have_link('A link', href: /non-existant/)
+    expect(@session).not_to have_link('A link', href: '/nonexistent-href')
+    expect(@session).not_to have_link('A link', href: /nonexistent/)
   end
 end
 
@@ -32,7 +32,7 @@ Capybara::SpecHelper.spec '#has_no_link?' do
 
   it "should be true if the given link is not on the page" do
     expect(@session).to have_no_link('monkey')
-    expect(@session).to have_no_link('A link', href: '/non-existant-href')
-    expect(@session).to have_no_link('A link', href: /\/non-existant-href/)
+    expect(@session).to have_no_link('A link', href: '/nonexistent-href')
+    expect(@session).to have_no_link('A link', href: /\/nonexistent-href/)
   end
 end

lib/capybara/spec/session/has_select_spec.rb

@@ -27,7 +27,7 @@ Capybara::SpecHelper.spec '#has_select?' do
       expect(@session).not_to have_select('Does not exist', selected: 'John')
       expect(@session).not_to have_select('City', selected: 'Not there')
       expect(@session).not_to have_select('Underwear', selected: [
-        'Boxerbriefs', 'Briefs', 'Commando', "Frenchman's Pantalons", 'Long Johns', 'Nonexistant'
+        'Boxerbriefs', 'Briefs', 'Commando', "Frenchman's Pantalons", 'Long Johns', 'Nonexistent'
       ])
       expect(@session).not_to have_select('Underwear', selected: [
         'Boxerbriefs', 'Briefs', 'Boxers', 'Commando', "Frenchman's Pantalons", 'Long Johns'
@@ -185,7 +185,7 @@ Capybara::SpecHelper.spec '#has_no_select?' do
       expect(@session).to have_no_select('Does not exist', selected: 'John')
       expect(@session).to have_no_select('City', selected: 'Not there')
       expect(@session).to have_no_select('Underwear', selected: [
-        'Boxerbriefs', 'Briefs', 'Commando', "Frenchman's Pantalons", 'Long Johns', 'Nonexistant'
+        'Boxerbriefs', 'Briefs', 'Commando', "Frenchman's Pantalons", 'Long Johns', 'Nonexistent'
       ])
       expect(@session).to have_no_select('Underwear', selected: [
         'Boxerbriefs', 'Briefs', 'Boxers', 'Commando', "Frenchman's Pantalons", 'Long Johns'

spec/capybara_spec.rb

@@ -139,7 +139,7 @@ RSpec.describe Capybara do
 end
 
 RSpec.describe Capybara::Session do
-  context 'with non-existant driver' do
+  context 'with nonexistent driver' do
     it "should raise an error" do
       expect {
         Capybara::Session.new(:quox, TestApp).driver