Update fetch for static page gen, fix DOM patching

go/wasmruntime/reconcile_test.go

@@ -0,0 +1,86 @@
+//go:build js && wasm
+
+package wasmruntime
+
+import (
+	"strings"
+	"testing"
+
+	"kjol/vdom"
+)
+
+// The reconciler is wasm-only and needs a DOM, so these do not run under a plain
+// `go test ./...` (the native build of this package is an empty placeholder).
+// Run them against the minimal DOM in testdata/domexec.js — from kjol/go:
+//
+//	GOOS=js GOARCH=wasm go test -exec="node testdata/domexec.js" ./wasmruntime
+
+// A Raw() node carries its markup in VNode.HTML and has NO children — the markup
+// only exists in the DOM. So when the diff reuses that element for a node that
+// has children instead (same tag, same index — e.g. a route change from a page
+// with a server-rendered SVG to one without), the new children must not simply be
+// appended alongside the surviving markup.
+func TestPatchClearsRawHTMLWhenElementIsReused(t *testing.T) {
+	root := document.Call("createElement", "div")
+
+	chart := vdom.El("div", vdom.Attr("class", "grid"),
+		vdom.El("div", vdom.Attr("class", "cell"), vdom.Raw(`<svg id="bar"></svg>`)),
+	)
+	patchChildren(root, nil, one(chart))
+	if got := root.Get("innerHTML").String(); !strings.Contains(got, `<svg id="bar">`) {
+		t.Fatalf("raw HTML was not mounted: %s", got)
+	}
+
+	// Same tags at the same indexes, so the diff adopts the DOM rather than
+	// replacing it.
+	data := vdom.El("div", vdom.Attr("class", "cards"),
+		vdom.El("div", vdom.Attr("class", "card"), vdom.Text("gob section")),
+	)
+	patchChildren(root, one(chart), one(data))
+
+	got := root.Get("innerHTML").String()
+	if strings.Contains(got, "svg") {
+		t.Errorf("stale raw HTML survived the patch (the chart would follow you to the next page):\n%s", got)
+	}
+	if !strings.Contains(got, "gob section") {
+		t.Errorf("new children were not rendered:\n%s", got)
+	}
+}
+
+// The reverse transition: an element with real children reused for a Raw() node.
+// innerHTML replaces the children wholesale, so nothing may linger.
+func TestPatchReplacesChildrenWithRawHTML(t *testing.T) {
+	root := document.Call("createElement", "div")
+
+	withKids := vdom.El("div", vdom.El("span", vdom.Text("hello")))
+	patchChildren(root, nil, one(withKids))
+
+	withRaw := vdom.El("div", vdom.Raw(`<svg id="pie"></svg>`))
+	patchChildren(root, one(withKids), one(withRaw))
+
+	got := root.Get("innerHTML").String()
+	if strings.Contains(got, "hello") || strings.Contains(got, "span") {
+		t.Errorf("old children survived under raw HTML:\n%s", got)
+	}
+	if !strings.Contains(got, `<svg id="pie">`) {
+		t.Errorf("raw HTML was not applied:\n%s", got)
+	}
+}
+
+// Raw markup that does not change must be left alone (it is not re-set on every
+// render, which would blow away any DOM state inside it).
+func TestPatchKeepsUnchangedRawHTML(t *testing.T) {
+	root := document.Call("createElement", "div")
+
+	a := vdom.El("div", vdom.Raw(`<svg id="bar"></svg>`))
+	patchChildren(root, nil, one(a))
+	before := rt(a).dom.Get("childNodes").Index(0)
+
+	b := vdom.El("div", vdom.Raw(`<svg id="bar"></svg>`))
+	patchChildren(root, one(a), one(b))
+
+	after := rt(b).dom.Get("childNodes").Index(0)
+	if !before.Equal(after) {
+		t.Error("unchanged raw HTML was re-parsed instead of being left in place")
+	}
+}