Add cop for time in expect

lib/ezcater_rubocop.rb

@@ -26,6 +26,7 @@
 require "rubocop/cop/ezcater/require_custom_error"
 require "rubocop/cop/ezcater/require_gql_error_helpers"
 require "rubocop/cop/ezcater/rspec_match_ordered_array"
+require "rubocop/cop/ezcater/rspec_assert_on_current_time"
 require "rubocop/cop/ezcater/rspec_require_browser_mock"
 require "rubocop/cop/ezcater/rspec_require_feature_flag_mock"
 require "rubocop/cop/ezcater/rspec_require_http_status_matcher"

lib/rubocop/cop/ezcater/rspec_assert_on_current_time.rb

@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Ezcater
+      # Enforce not using Time in an assertion
+      #
+      # @example
+      #
+      #   # good
+      #   let(:current_time) { Time.zone.now } [outside of test]
+      #   expect(foo).to eq(current_time)
+      #
+      #   # bad
+      #   expect(foo).to eq(Time.zone.now)
+      #   expect(foo).to eq({a: { b: Time.zone.now }})
+      class RspecAssertOnCurrentTime < Cop
+        MSG = "Do not call Time in an assertion. Memoize the value outside the spec and use that instead."
+
+        def_node_matcher "expect", <<~PATTERN
+          (send (send nil? :expect (...)) :to $...)
+        PATTERN
+
+        def_node_matcher "time", <<~PATTERN
+          (:const nil? :Time)
+        PATTERN
+
+        def on_send(node)
+          expect(node) do |expect_input|
+            expect_input.each do |input|
+              recursively_look_for_time(input)
+            end
+          end
+        end
+
+        def recursively_look_for_time(node)
+          return unless node.is_a?(RuboCop::AST::Node)
+
+          node&.children&.each do |child|
+            next unless child.respond_to?(:children)
+
+            time(child) do
+              add_offense(child, location: :expression, message: MSG)
+            end
+
+            child.children.each do |inner_child|
+              recursively_look_for_time(inner_child)
+            end
+          end
+        end
+      end
+    end
+  end
+end

spec/rubocop/cop/ezcater/rspec_assert_on_current_time_spec.rb

@@ -0,0 +1,42 @@
+# encoding utf-8
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::Ezcater::RspecAssertOnCurrentTime, :config do
+  subject(:cop) { described_class.new(config) }
+
+  it "corrects when using Time inside expect" do
+    source = "expect(foo).to match(Time.zone.now)"
+
+    inspect_source(source)
+
+    expect(cop.offenses).not_to be_empty
+    expect(cop.highlights).to match_array("Time")
+    expect(cop.messages).to match_array(described_class::MSG)
+  end
+
+  it "corrects when using Time nested inside expect" do
+    source = "expect(foo).to match({a: { b: Time.zone.now }})"
+
+    inspect_source(source)
+
+    expect(cop.offenses).not_to be_empty
+    expect(cop.highlights).to match_array("Time")
+    expect(cop.messages).to match_array(described_class::MSG)
+  end
+
+  it "accepts when using expect without a call to Time" do
+    source = "expect(foo).to match(current_time)"
+
+    inspect_source(source)
+
+    expect(cop.offenses).to be_empty
+  end
+
+  it "accepts when using Time outside of expect" do
+    source = "let(:a_time) { Time.zone.now }"
+
+    inspect_source(source)
+
+    expect(cop.offenses).to be_empty
+  end
+end