fix: allow underscores in formula name (#2205)

* fix: allow underscores in formula name

I was trying to create two formulas per release. One signifying the latest and
another with the version explicitly: formula.rb and formula@v0.0.0.rb

The filenames are fine but the formula name for the explicit version
was created as FormulaATv0.0.0 which isn't valid Ruby.

Looking at the function history I couldn't find why underscores were being replaced
since underscores are valid for Ruby identifiers. I opted to replace dots in a formula with
underscores

- 1399a39603
- https://ruby-doc.org/docs/ruby-doc-bundle/Manual/man-1.4/syntax.html#ident

* test: add test for version in formula name

I think underscores are removed to make the Formula name cleaner

* test: re-add old test

internal/pipe/brew/brew.go

@@ -323,9 +323,14 @@ func split(s string) []string {
 	return strings
 }
 
+// formulaNameFor transforms the formula name into a form
+// that more resembles a valid Ruby class name
+// e.g. foo_bar@v6.0.0-rc is turned into FooBarATv6_0_0RC
+// The order of these replacements is important
 func formulaNameFor(name string) string {
 	name = strings.ReplaceAll(name, "-", " ")
 	name = strings.ReplaceAll(name, "_", " ")
+	name = strings.ReplaceAll(name, ".", "_")
 	name = strings.ReplaceAll(name, "@", "AT")
 	return strings.ReplaceAll(strings.Title(name), " ", "")
 }

internal/pipe/brew/brew_test.go

@@ -31,6 +31,10 @@ func TestNameWithUnderline(t *testing.T) {
 	require.Equal(t, formulaNameFor("some_binary"), "SomeBinary")
 }
 
+func TestNameWithDots(t *testing.T) {
+	require.Equal(t, formulaNameFor("binaryv0.0.0"), "Binaryv0_0_0")
+}
+
 func TestNameWithAT(t *testing.T) {
 	require.Equal(t, formulaNameFor("some_binary@1"), "SomeBinaryAT1")
 }