Improve existing tests for Livecheck DSL

Library/Homebrew/test/livecheck_spec.rb

@@ -4,19 +4,25 @@ require "formula"
 require "livecheck"
 
 describe Livecheck do
+  HOMEPAGE_URL = "https://example.com/"
+  STABLE_URL = "https://example.com/example-1.2.3.tar.gz"
+  HEAD_URL = "https://example.com/example.git"
+
   let(:f) do
     formula do
-      url "https://brew.sh/test-0.1.tbz"
+      homepage HOMEPAGE_URL
+      url STABLE_URL
+      head HEAD_URL
     end
   end
   let(:livecheckable) { described_class.new(f) }
 
   describe "#regex" do
-    it "returns nil if unset" do
+    it "returns nil if not set" do
       expect(livecheckable.regex).to be nil
     end
 
-    it "returns the Regex if set" do
+    it "returns the Regexp if set" do
       livecheckable.regex(/foo/)
       expect(livecheckable.regex).to eq(/foo/)
     end
@@ -29,14 +35,14 @@ describe Livecheck do
   end
 
   describe "#skip" do
-    it "sets the instance variable skip to true and skip_msg to nil when the argument is not present" do
-      livecheckable.skip
+    it "sets @skip to true when no argument is provided" do
+      expect(livecheckable.skip).to be true
       expect(livecheckable.instance_variable_get(:@skip)).to be true
       expect(livecheckable.instance_variable_get(:@skip_msg)).to be nil
     end
 
-    it "sets the instance variable skip to true and skip_msg to the argument when present" do
-      livecheckable.skip("foo")
+    it "sets @skip to true and @skip_msg to the provided String" do
+      expect(livecheckable.skip("foo")).to be true
       expect(livecheckable.instance_variable_get(:@skip)).to be true
       expect(livecheckable.instance_variable_get(:@skip_msg)).to eq("foo")
     end
@@ -49,8 +55,9 @@ describe Livecheck do
   end
 
   describe "#skip?" do
-    it "returns the value of the instance variable skip" do
+    it "returns the value of @skip" do
       expect(livecheckable.skip?).to be false
+
       livecheckable.skip
       expect(livecheckable.skip?).to be true
     end
@@ -74,7 +81,7 @@ describe Livecheck do
   end
 
   describe "#url" do
-    it "returns nil if unset" do
+    it "returns nil if not set" do
       expect(livecheckable.url).to be nil
     end
 
@@ -82,6 +89,16 @@ describe Livecheck do
       livecheckable.url("foo")
       expect(livecheckable.url).to eq("foo")
 
+      livecheckable.url(:homepage)
+      expect(livecheckable.url).to eq(HOMEPAGE_URL)
+
+      livecheckable.url(:stable)
+      expect(livecheckable.url).to eq(STABLE_URL)
+
+      livecheckable.url(:head)
+      expect(livecheckable.url).to eq(HEAD_URL)
+    end
+
     it "raises a TypeError if the argument isn't a String or Symbol" do
       expect {
         livecheckable.url(/foo/)