Feat: docs, code frm percy

packages/virtual-dom-rs/src/diff/diff_test_case.rs

@@ -0,0 +1,26 @@
+//! Kept in it's own file to more easily import into the Percy book.
+
+use crate::diff::diff;
+use crate::patch::Patch;
+use virtual_node::VirtualNode;
+
+/// Test that we generate the right Vec<Patch> for some start and end virtual dom.
+pub struct DiffTestCase<'a> {
+    // ex: "Patching root level nodes works"
+    pub description: &'static str,
+    // ex: html! { <div> </div> }
+    pub old: VirtualNode,
+    // ex: html! { <strong> </strong> }
+    pub new: VirtualNode,
+    // ex: vec![Patch::Replace(0, &html! { <strong></strong> })],
+    pub expected: Vec<Patch<'a>>,
+}
+
+impl<'a> DiffTestCase<'a> {
+    pub fn test(&self) {
+        // ex: vec![Patch::Replace(0, &html! { <strong></strong> })],
+        let patches = diff(&self.old, &self.new);
+
+        assert_eq!(patches, self.expected, "{}", self.description);
+    }
+}