RenderCache Saves What Web Components Render

Sites built with Lit, Stencil and other web-component libraries used to come out almost empty in RenderCache’s saved copies, because a component’s content lives in a shadow root that ordinary HTML leaves out. RenderCache 0.4.0 writes it in, with slotted content in place, and does the same for iframes that show another page of the same site.

An independent review found eight problems before release, including lazy frames saved as empty boxes and error pages written into snapshots. All are fixed with tests. It follows 0.3.0, which added crawler verification.