Resolve src refs for img and script

Handle absolute to relative resolution of the src attribute for img and
script elements.

src/utils/resolve-refs.test.tsx

@@ -25,6 +25,16 @@ suite("function resolveRefs", () => {
 		assert.equal((el as Element).attributes.get("href"), "../alt/page.html");
 	});
 
+	test("script src", () => {
+		const el = resolveRefs(<script src="/assets/script.js"></script>, "/subdir");
+		assert.equal((el as Element).attributes.get("src"), "../assets/script.js");
+	});
+
+	test("img src", () => {
+		const el = resolveRefs(<img src="/assets/image.png"></img>, "/subdir");
+		assert.equal((el as Element).attributes.get("src"), "../assets/image.png");
+	});
+
 	test("nested element", () => {
 		const el = resolveRefs(<div>Content with <a href="/page.html">Link</a></div>, "/");
 		assert.equal((el.childNodes[1] as Element).attributes.get("href"), "page.html");

src/utils/resolve-refs.ts

@@ -8,6 +8,13 @@ function shallowCopyElement(element: Element) {
 	return copy;
 }
 
+const resolvedAttributes = new Map([
+	["a", "href"],
+	["img", "src"],
+	["link", "href"],
+	["script", "src"],
+]);
+
 /**
 	Resolves absolute href attributes in a and link elements the Node tree into relative references from the given directory.
 
@@ -21,20 +28,18 @@ export function resolveRefs(node: Node, dir: string) {
 	}
 	let resolvedNode = node;
 	const name = node.name;
-	if (
+	let attribute = resolvedAttributes.get(name);
-		(name === "link" || name === "a")
+	if (attribute && node.attributes.has(attribute)) {
-		&& node.attributes.has("href")
+		const original = node.attributes.get(attribute)!
-	) {
-		const original = node.attributes.get("href")!
 		if (/^[a-z][a-z+.-]*:/i.test(original)) {
 			// Ignore refs that start with a URI scheme.
 		/* node:coverage ignore next 3 */
 		} else if (!original.startsWith("/")) {
-			console.log(`Warning: found relative href to ${original}`);
+			console.log(`Warning: found relative ${attribute} to ${original}`);
 		} else {
 			const ref = posix.relative(dir, original);
 			resolvedNode = shallowCopyElement(node);
-			resolvedNode.attributes.set("href", ref);
+			resolvedNode.attributes.set(attribute, ref);
 		}
 	}
 	const resolvedChildren: Node[] = [];