fix: retry endpoint on status code 500

previously, it would give up on that endpoint and move on to the next
one. most of the time, a status code 500, a server side error, is a
one-off.

lib/info.js

@@ -184,7 +184,7 @@ const retryFunc = async(func, args, options) => {
       result = await func(...args);
       break;
     } catch (err) {
-      if (err instanceof miniget.MinigetError || currentTry >= options.maxRetries) {
+      if ((err instanceof miniget.MinigetError && err.statusCode < 500) || currentTry >= options.maxRetries) {
         throw err;
       }
       let wait = Math.min(++currentTry * options.backoff.inc, options.backoff.max);

package.json

@@ -37,7 +37,7 @@
   "dependencies": {
     "html-entities": "^1.3.1",
     "m3u8stream": "^0.8.1",
-    "miniget": "^3.0.0",
+    "miniget": "^3.1.0",
     "sax": "^1.1.3"
   },
   "devDependencies": {

test/files/refresh.js

@@ -64,16 +64,13 @@ const videos = [
   {
     id: '_HSylqgVYQI',
     type: 'regular',
-    keep: ['video.flv', 'watch-reload-now-2.json'],
+    keep: ['video.flv', 'watch-reload-now.json', 'watch-reload-now-2.json'],
     saveInfo: true,
     transform: [
       {
         page: 'watch.json',
         saveAs: 'no-extras',
-        fn: body => {
-          body = body.replace('playerMicroformatRenderer', '');
-          return body;
-        },
+        fn: body => body.replace('playerMicroformatRenderer', ''),
       },
       {
         page: 'watch.html',

test/files/videos/regular/watch-reload-now.json

@@ -0,0 +1 @@
+{"reload":"now"}

test/info-test.js

@@ -345,7 +345,6 @@ describe('ytdl.getInfo()', () => {
         const id = 'LuZu9N53Vd0';
         const scope = nock(id, 'age-restricted', {
           watchJson: [true, 200, 'bad-config'],
-          watchHtml: false,
         });
         let info = await ytdl.getInfo(id);
         scope.done();
@@ -371,29 +370,79 @@ describe('ytdl.getInfo()', () => {
     });
 
     describe('When watch page gives back `{"reload":"now"}`', () => {
-      it('Uses backup embed.html page', async() => {
-        const id = 'LuZu9N53Vd0';
-        const scope = nock(id, 'age-restricted', {
+      it('Retries the request', async() => {
+        const id = '_HSylqgVYQI';
+        const scope1 = nock(id, 'regular', {
           watchJson: [true, 200, 'reload-now'],
         });
-        const scope2 = nock(id, 'age-restricted', {
-          watchJson: [true, 200, 'reload-now'],
-          embed: false,
-          get_video_info: false,
+        const scope2 = nock(id, 'regular', {
+          watchHtml: false,
           player: false,
         });
-        let info = await ytdl.getInfo(id, {
-          requestOptions: {
-            maxRetries: 1,
-            backoff: { inc: 0 },
-          },
+        let info = await ytdl.getInfo(id, { requestOptions: { maxRetries: 1 } });
+        scope1.done();
+        scope2.done();
+        assert.ok(info.formats.length);
+        assert.ok(info.formats[0].url);
+      });
+
+      describe('Too many times', () => {
+        it('Uses backup embed.html page', async() => {
+          const id = 'LuZu9N53Vd0';
+          const scope = nock(id, 'age-restricted', {
+            watchJson: [true, 200, 'reload-now'],
+          });
+          const scope2 = nock(id, 'age-restricted', {
+            watchJson: [true, 200, 'reload-now'],
+            embed: false,
+            get_video_info: false,
+            player: false,
+          });
+          let info = await ytdl.getInfo(id, {
+            requestOptions: {
+              maxRetries: 1,
+              backoff: { inc: 0 },
+            },
+          });
+          scope.done();
+          scope2.done();
+          assert.ok(info.html5player);
+          assert.ok(info.formats.length);
+          assert.ok(info.formats[0].url);
         });
-        scope.done();
+      });
+    });
+
+    describe('When an endpoint gives back a 500 server error', () => {
+      it('Retries the request', async() => {
+        const id = '_HSylqgVYQI';
+        const scope1 = nock(id, 'regular', {
+          watchJson: [true, 502],
+        });
+        const scope2 = nock(id, 'regular', {
+          watchHtml: false,
+          player: false,
+        });
+        let info = await ytdl.getInfo(id, { requestOptions: { maxRetries: 1 } });
+        scope1.done();
         scope2.done();
-        assert.ok(info.html5player);
         assert.ok(info.formats.length);
         assert.ok(info.formats[0].url);
       });
+
+      describe('Too many times', () => {
+        it('Uses the next endpoint as backup', async() => {
+          const id = 'LuZu9N53Vd0';
+          const scope = nock(id, 'age-restricted', {
+            watchJson: [true, 502],
+          });
+          let info = await ytdl.getInfo(id);
+          scope.done();
+          assert.ok(info.html5player);
+          assert.ok(info.formats.length);
+          assert.ok(info.formats[0].url);
+        });
+      });
     });
   });