1 files changed, 54 insertions, 0 deletions
diff --git a/app/models/protected_ref_matcher.rb b/app/models/protected_ref_matcher.rb
new file mode 100644
index 00000000000..d970f2b01fc
--- /dev/null
+++ b/app/models/protected_ref_matcher.rb
@@ -0,0 +1,54 @@
+class ProtectedRefMatcher
+  def initialize(protected_ref)
+    @protected_ref = protected_ref
+  end
+
+  # Returns all protected refs that match the given ref name.
+  # This checks all records from the scope built up so far, and does
+  # _not_ return a relation.
+  #
+  # This method optionally takes in a list of `protected_refs` to search
+  # through, to avoid calling out to the database.
+  def self.matching(type, ref_name, protected_refs: nil)
+    (protected_refs || type.all).select { |protected_ref| protected_ref.matches?(ref_name) }
+  end
+
+  # Returns all branches/tags (among the given list of refs [`Gitlab::Git::Branch`])
+  # that match the current protected ref.
+  def matching(refs)
+    refs.select { |ref| @protected_ref.matches?(ref.name) }
+  end
+
+  # Checks if the protected ref matches the given ref name.
+  def matches?(ref_name)
+    return false if @protected_ref.name.blank?
+
+    exact_match?(ref_name) || wildcard_match?(ref_name)
+  end
+
+  # Checks if this protected ref contains a wildcard
+  def wildcard?
+    @protected_ref.name && @protected_ref.name.include?('*')
+  end
+
+  protected
+
+  def exact_match?(ref_name)
+    @protected_ref.name == ref_name
+  end
+
+  def wildcard_match?(ref_name)
+    return false unless wildcard?
+
+    wildcard_regex === ref_name
+  end
+
+  def wildcard_regex
+    @wildcard_regex ||= begin
+      name = @protected_ref.name.gsub('*', 'STAR_DONT_ESCAPE')
+      quoted_name = Regexp.quote(name)
+      regex_string = quoted_name.gsub('STAR_DONT_ESCAPE', '.*?')
+      /\A#{regex_string}\z/
+    end
+  end
+end