Add support for full URLs in image plugin.

eleventy.config.images.js

@@ -1,22 +1,38 @@
 const path = require("path");
 const eleventyImage = require("@11ty/eleventy-img");
 
-module.exports = eleventyConfig => {
-	function relativeToInputPath(inputPath, relativeFilePath) {
+function relativeToInputPath(inputPath, relativeFilePath) {
 	let split = inputPath.split("/");
 	split.pop();
 
 	return path.resolve(split.join(path.sep), relativeFilePath);
-	}
 
+}
+
+function isFullUrl(url) {
+	try {
+		new URL(url);
+		return true;
+	} catch(e) {
+		return false;
+	}
+}
+
+module.exports = function(eleventyConfig) {
 	// Eleventy Image shortcode
 	// https://www.11ty.dev/docs/plugins/image/
 	eleventyConfig.addAsyncShortcode("image", async function imageShortcode(src, alt, widths, sizes) {
 		// Full list of formats here: https://www.11ty.dev/docs/plugins/image/#output-formats
 		// Warning: Avif can be resource-intensive so take care!
 		let formats = ["avif", "webp", "auto"];
-		let file = relativeToInputPath(this.page.inputPath, src);
-		let metadata = await eleventyImage(file, {
+		let input;
+		if(isFullUrl(src)) {
+			input = src;
+		} else {
+			input = relativeToInputPath(this.page.inputPath, src);
+		}
+
+		let metadata = await eleventyImage(input, {
 			widths: widths || ["auto"],
 			formats,
 			outputDir: path.join(eleventyConfig.dir.output, "img"), // Advanced usage note: `eleventyConfig.dir` works here because we’re using addPlugin.
@@ -29,6 +45,7 @@ module.exports = eleventyConfig => {
 			loading: "lazy",
 			decoding: "async",
 		};
+
 		return eleventyImage.generateHTML(metadata, imageAttributes);
 	});
 };