Add test helper for normalize/regex_spec (#14545)

spec/compiler/normalize/regex_spec.cr

@@ -1,30 +1,60 @@
 require "../../spec_helper"
 
+private def assert_expand_regex_const(from : String, to, *, flags = nil, file = __FILE__, line = __LINE__)
+  from_nodes = Parser.parse(from)
+  assert_expand(from_nodes, flags: flags, file: file, line: line) do |to_nodes, program|
+    const = program.types[to_nodes.to_s].should be_a(Crystal::Const), file: file, line: line
+    const.value.to_s.should eq(to.strip), file: file, line: line
+  end
+end
+
 describe "Normalize: regex literal" do
+  describe "StringLiteral" do
+    it "expands to const" do
+      assert_expand Parser.parse(%q(/foo/)) do |to_nodes, program|
+        to_nodes.to_s.should eq "$Regex:0"
+      end
+    end
+
+    it "simple" do
+      assert_expand_regex_const %q(/foo/), <<-'CRYSTAL'
+      ::Regex.new("foo", ::Regex::Options.new(0))
+      CRYSTAL
+    end
+  end
+
+  describe "StringInterpolation" do
+    it "simple" do
+      assert_expand %q(/#{"foo".to_s}/), <<-'CRYSTAL'
+        ::Regex.new("#{"foo".to_s}", ::Regex::Options.new(0))
+        CRYSTAL
+    end
+  end
+
   describe "options" do
     it "empty" do
-      assert_expand %q(/#{"".to_s}/), <<-'CRYSTAL'
-      ::Regex.new("#{"".to_s}", ::Regex::Options.new(0))
+      assert_expand_regex_const %q(//), <<-'CRYSTAL'
+      ::Regex.new("", ::Regex::Options.new(0))
       CRYSTAL
     end
     it "i" do
-      assert_expand %q(/#{"".to_s}/i), <<-'CRYSTAL'
-      ::Regex.new("#{"".to_s}", ::Regex::Options.new(1))
+      assert_expand_regex_const %q(//i), <<-'CRYSTAL'
+      ::Regex.new("", ::Regex::Options.new(1))
       CRYSTAL
     end
     it "x" do
-      assert_expand %q(/#{"".to_s}/x), <<-'CRYSTAL'
-      ::Regex.new("#{"".to_s}", ::Regex::Options.new(8))
+      assert_expand_regex_const %q(//x), <<-'CRYSTAL'
+      ::Regex.new("", ::Regex::Options.new(8))
       CRYSTAL
     end
     it "im" do
-      assert_expand %q(/#{"".to_s}/im), <<-'CRYSTAL'
-      ::Regex.new("#{"".to_s}", ::Regex::Options.new(7))
+      assert_expand_regex_const %q(//im), <<-'CRYSTAL'
+      ::Regex.new("", ::Regex::Options.new(7))
       CRYSTAL
     end
     it "imx" do
-      assert_expand %q(/#{"".to_s}/imx), <<-'CRYSTAL'
-      ::Regex.new("#{"".to_s}", ::Regex::Options.new(15))
+      assert_expand_regex_const %q(//imx), <<-'CRYSTAL'
+      ::Regex.new("", ::Regex::Options.new(15))
       CRYSTAL
     end
   end

spec/spec_helper.cr

@@ -124,10 +124,16 @@ def assert_expand(from : String, to, *, flags = nil, file = __FILE__, line = __L
 end
 
 def assert_expand(from_nodes : ASTNode, to, *, flags = nil, file = __FILE__, line = __LINE__)
+  assert_expand(from_nodes, flags: flags, file: file, line: line) do |to_nodes|
+    to_nodes.to_s.strip.should eq(to.strip), file: file, line: line
+  end
+end
+
+def assert_expand(from_nodes : ASTNode, *, flags = nil, file = __FILE__, line = __LINE__, &)
   program = new_program
   program.flags.concat(flags.split) if flags
   to_nodes = LiteralExpander.new(program).expand(from_nodes)
-  to_nodes.to_s.strip.should eq(to.strip), file: file, line: line
+  yield to_nodes, program
 end
 
 def assert_expand_second(from : String, to, *, flags = nil, file = __FILE__, line = __LINE__)