Re-enable support for Ruby 2.7

We should make one release which claims to support Ruby 2.7 and also
actually supports Ruby 2.7 so that Gemfiles on older Rubies can pick up
a working version.

After release I will revert this commit so that we can move forward on
3.1+.

app/helpers/importmap/importmap_tags_helper.rb

@@ -3,7 +3,7 @@ module Importmap::ImportmapTagsHelper
   def javascript_importmap_tags(entry_point = "application", importmap: Rails.application.importmap)
     safe_join [
       javascript_inline_importmap_tag(importmap.to_json(resolver: self)),
-      javascript_importmap_module_preload_tags(importmap, entry_point:),
+      javascript_importmap_module_preload_tags(importmap, entry_point: entry_point),
       javascript_import_module_tag(entry_point)
     ], "\n"
   end
@@ -25,7 +25,7 @@ def javascript_import_module_tag(*module_names)
   # (defaults to Rails.application.importmap), such that they'll be fetched
   # in advance by browsers supporting this link type (https://caniuse.com/?search=modulepreload).
   def javascript_importmap_module_preload_tags(importmap = Rails.application.importmap, entry_point: "application")
-    javascript_module_preload_tag(*importmap.preloaded_module_paths(resolver: self, entry_point:, cache_key: entry_point))
+    javascript_module_preload_tag(*importmap.preloaded_module_paths(resolver: self, entry_point: entry_point, cache_key: entry_point))
   end
 
   # Link tag(s) for preloading the JavaScript module residing in `*paths`. Will return one link tag per path element.

importmap-rails.gemspec

@@ -14,7 +14,7 @@ Gem::Specification.new do |spec|
 
   spec.files = Dir["{app,lib}/**/*", "MIT-LICENSE", "Rakefile", "README.md"]
 
-  spec.required_ruby_version = ">= 3.1.0"
+  spec.required_ruby_version = ">= 2.7.0"
   spec.add_dependency "railties", ">= 6.0.0"
   spec.add_dependency "activesupport", ">= 6.0.0"
   spec.add_dependency "actionpack", ">= 6.0.0"

lib/importmap/map.rb

@@ -42,7 +42,7 @@ def pin_all_from(dir, under: nil, to: nil, preload: true)
   # the different cases.
   def preloaded_module_paths(resolver:, entry_point: "application", cache_key: :preloaded_module_paths)
     cache_as(cache_key) do
-      resolve_asset_paths(expanded_preloading_packages_and_directories(entry_point:), resolver:).values
+      resolve_asset_paths(expanded_preloading_packages_and_directories(entry_point: entry_point), resolver: resolver).values
     end
   end