Add script to upgrade HAML syntax

[skip-ci]

spec/lib/haml_up_spec.rb

@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'haml_up'
+
+describe HamlUp do
+  describe "#rewrite_template" do
+    it "preserves a simple template" do
+      original = "%p This is a paragraph"
+      template = call(original)
+      expect(template).to eq original
+    end
+
+    it "rewrites non-standard attribute hashes" do
+      original = "%p{ng: {click: 'action', show: 'condition'}} label"
+      template = call(original)
+      expect(template).to eq "%p{ \"ng-click\" => 'action', \"ng-show\" => 'condition' } label"
+    end
+
+    it "preserves standard attribute hashes" do
+      original = "%p{data: {click: 'action', show: 'condition'}} label"
+      template = call(original)
+      expect(template).to eq original
+    end
+
+    it "preserves standard attribute hashes while rewriting others" do
+      original = "%p{data: {click: 'standard'}, ng: {click: 'not'}} label"
+      template = call(original)
+      expect(template).to eq "%p{ \"data\" => {click: 'standard'}, \"ng-click\" => 'not' } label"
+    end
+
+    it "rewrites multi-line attributes" do
+      original = <<~HAML
+        %li{ ng: { class: "{active: selector.active}" } }
+          %a{ "tooltip" => "{{selector.object.value}}", "tooltip-placement" => "bottom",
+            ng: { transclude: true, class: "{active: selector.active, 'has-tip': selector.object.value}" } }
+      HAML
+      expected = <<~HAML
+        %li{ "ng-class" => "{active: selector.active}" }
+          %a{ "tooltip" => "{{selector.object.value}}", "tooltip-placement" => "bottom", "ng-transclude" => true, "ng-class" => "{active: selector.active, 'has-tip': selector.object.value}" }
+      HAML
+      template = call(original)
+      expect(template).to eq expected
+    end
+
+    def call(original)
+      original.dup.tap { |t| subject.rewrite_template(t) }
+    end
+  end
+end