fix(sirv): avoid false-positive on too big range end (#147)

* fix(sirv): avoid false-positive on too big range end

* chore: move assertions

---------

Co-authored-by: Luke Edwards <luke.edwards05@gmail.com>

packages/sirv/index.js

@@ -73,7 +73,11 @@ function send(req, res, file, stats, headers) {
 		let end = opts.end = parseInt(y, 10) || stats.size - 1;
 		let start = opts.start = parseInt(x, 10) || 0;
 
-		if (start >= stats.size || end >= stats.size) {
+		if (end >= stats.size) {
+			end = stats.size - 1;
+		}
+
+		if (start >= stats.size) {
 			res.setHeader('Content-Range', `bytes */${stats.size}`);
 			res.statusCode = 416;
 			return res.end();

tests/sirv.js

@@ -1017,11 +1017,11 @@ ranges('should assume the end-value is final byte when not included :: full', as
 	}
 });
 
-ranges('should throw `416` when range cannot be met (overflow)', async () => {
+ranges('should throw `416` when range start cannot be met (overflow)', async () => {
 	let server = utils.http();
 
 	try {
-		let headers = { Range: 'bytes=0-123456' };
+		let headers = { Range: 'bytes=123456-234567' };
 		let file = await utils.lookup('bundle.67329.js', 'utf8');
 		await server.send('GET', '/bundle.67329.js', { headers }).catch(err => {
 			assert.is(err.headers['content-range'], `bytes */${file.size}`);
@@ -1032,6 +1032,20 @@ ranges('should throw `416` when range cannot be met (overflow)', async () => {
 	}
 });
 
+ranges('should shrink range end if it cannot be met (overflow)', async () => {
+	let server = utils.http();
+
+	try {
+		let headers = { Range: 'bytes=10-123456' };
+		let file = await utils.lookup('bundle.67329.js', 'utf8');
+		let res = await server.send('GET', '/bundle.67329.js', { headers });
+		assert.is(res.headers['content-range'], `bytes 10-${file.size - 1}/${file.size}`);
+		assert.is(res.statusCode, 206);
+	} finally {
+		server.close();
+	}
+});
+
 ranges('should not mutate response headers on subsequent non-Range requests :: dev', async () => {
 	let server = utils.http({ dev: true });