Parser: Support ternaries with transform_conditionals option

[marcoroth]

This pull request extends transform_conditionals to handle ternary expressions (condition ? 'yes' : 'no') in ERB output tags, transforming them into ERBIfNode/ERBElseNode structures.

The following:

<%= condition ? 'yes' : 'no' %>

is transformed to the equivalent with transform_conditionals: true:

<% if condition %><%= 'yes' %><% else %><%= 'no' %><% end %>

This also works inside attribute values, open tags, and nested within postfix conditionals:

<%= (condition? ? "true" : "false") if another_condition? %>

becomes:

<% if another_condition? %><% if condition? %><%= "true" %><% else %><%= "false" %><% end %><% end %>

The ternary transform is split into its own file (ternary_conditionals.c) separate from the postfix conditional transform (postfix_conditionals.c). The transform_ternary_expression function is exported so that postfix_conditionals.c can call it when a nested ternary is detected inside a postfix body.

Follows up on #1560 which added postfix support and intentionally named the option transform_conditionals to allow for this extension.

A future optimization could be to extract literal values directly as LiteralNodes or the proper equivalent. So that:

<%= condition ? 'yes' : 'no' %>

could become:

- <% if condition %><%= 'yes' %><% else %><%= 'no' %><% end %>
+ <% if condition %>yes<% else %>no<% end %>

[pkg-pr-new]

npx https://pkg.pr.new/@herb-tools/formatter@1594

npx https://pkg.pr.new/@herb-tools/language-server@1594

npx https://pkg.pr.new/@herb-tools/linter@1594

commit: 6475b9e

[github-actions]

🌿 Interactive Playground and Documentation Preview

A preview deployment has been built for this pull request. Try out the changes live in the interactive playground:

• Playground Preview
• Documentation Preview
• Website Preview

---

_{🌱 Grown from commit 6475b9e}

---

✅ Preview deployment has been cleaned up.