rubocops/cask: Ensure that "verified" URLs with paths end with "/"

- These were being fixed manually[1], so let's make a RuboCop for any
  further occurrences since this is a good rule to enforce[2].

[1] - https://github.com/Homebrew/homebrew-cask/pull/144179#issuecomment-1489857249
[2] - https://github.com/Homebrew/homebrew-cask/pull/80965#issuecomment-616232313

Library/Homebrew/rubocops/cask/url.rb

@@ -8,13 +8,13 @@ module RuboCop
       #
       # @example
       #   # bad
-      #   url "https://example.com/foo.dmg",
-      #     verified: "https://example.com"
+      #   url "https://example.com/download/foo.dmg",
+      #     verified: "https://example.com/download"
       #
       #
       #   # good
-      #   url "https://example.com/foo.dmg",
-      #     verified: "example.com"
+      #   url "https://example.com/download/foo.dmg",
+      #     verified: "example.com/download/"
       #
       class Url < Base
         extend AutoCorrector
@@ -30,8 +30,8 @@ module RuboCop
           hash_node.each_pair do |key_node, value_node|
             next unless key_node.source == "verified"
             next unless value_node.str_type?
-            next unless value_node.source.start_with?(%r{^"https?://})
 
+            if value_node.source.start_with?(%r{^"https?://})
               add_offense(
                 value_node.source_range,
                 message: "Verified URL parameter value should not start with https:// or http://.",
@@ -39,6 +39,17 @@ module RuboCop
                 corrector.replace(value_node.source_range, value_node.source.gsub(%r{^"https?://}, "\""))
               end
             end
+
+            next unless value_node.str_content.gsub(%r{https?://}, "").include?("/") # Skip if the stanza has no path.
+            next if value_node.str_content.end_with?("/")
+
+            add_offense(
+              value_node.source_range,
+              message: "Verified URL parameter value should end with a /.",
+            ) do |corrector|
+              corrector.replace(value_node.source_range, value_node.source.gsub(/"$/, "/\""))
+            end
+          end
         end
       end
     end

Library/Homebrew/test/rubocops/cask/url_spec.rb

@@ -54,4 +54,50 @@ describe RuboCop::Cop::Cask::Url do
     include_examples "reports offenses"
     include_examples "autocorrects source"
   end
+
+  context "when url 'verified' value has a path component that ends with a /" do
+    let(:source) do
+      <<~CASK
+        cask "foo" do
+          url "https://example.com/download/foo-v1.2.0.dmg",
+            verified: "example.com/download/"
+        end
+      CASK
+    end
+
+    include_examples "does not report any offenses"
+  end
+
+  context "when the url 'verified' value has a path component that doesn't end with a /" do
+    let(:source) do
+      <<~CASK
+        cask "foo" do
+          url "https://example.com/download/foo-v1.2.0.dmg",
+            verified: "example.com/download"
+        end
+      CASK
+    end
+
+    let(:expected_offenses) do
+      [{
+        message:  "Verified URL parameter value should end with a /.",
+        severity: :convention,
+        line:     3,
+        column:   14,
+        source:   "\"example.com/download\"",
+      }]
+    end
+
+    let(:correct_source) do
+      <<~CASK
+        cask "foo" do
+          url "https://example.com/download/foo-v1.2.0.dmg",
+            verified: "example.com/download/"
+        end
+      CASK
+    end
+
+    include_examples "reports offenses"
+    include_examples "autocorrects source"
+  end
 end