       expect(styleElementAddedHandler).toHaveBeenCalled()
 
       element = document.querySelector('head style[source-path*="css.css"]')
-      expect(element.getAttribute('source-path')).toEqualPath atom.themes.stringToId(cssPath)
+      expect(element.getAttribute('source-path')).toEqualPath cssPath
       expect(element.textContent).toBe fs.readFileSync(cssPath, 'utf8')
 
       # doesn't append twice


    it "supports requiring css and less stylesheets without an explicit extension", ->
      atom.themes.requireStylesheet path.join(__dirname, 'fixtures', 'css')
      expect(document.querySelector('head style[source-path*="css.css"]').getAttribute('source-path')).toEqualPath atom.themes.stringToId(atom.project.getDirectories()[0]?.resolve('css.css'))
      atom.themes.requireStylesheet path.join(__dirname, 'fixtures', 'sample')
      expect(document.querySelector('head style[source-path*="sample.less"]').getAttribute('source-path')).toEqualPath atom.themes.stringToId(atom.project.getDirectories()[0]?.resolve('sample.less'))

      document.querySelector('head style[source-path*="css.css"]').remove()
      document.querySelector('head style[source-path*="sample.less"]').remove()

      expect(document.querySelectorAll('head style').length).toBe lengthBefore + 1

      element = document.querySelector('head style[source-path*="sample.less"]')
      expect(element.getAttribute('source-path')).toEqualPath lessPath
      expect(element.textContent).toBe """
      #header {
        color: #4d926f;
