Improve viewport check (#1116)

* warn instead of fail on tap delay

* add viewport check to websites and stories

* improve wording

* update test

packages/linter/src/index.ts

@@ -116,6 +116,7 @@ function testsForMode(type: LintMode) {
     AmpImgAmpPixelPreferred,
     EndpointsAreAccessibleFromOrigin,
     EndpointsAreAccessibleFromCache,
+    ViewportDisablesTapDelay,
   ]);
   tests.set(
     LintMode.AmpStory,
@@ -131,6 +132,7 @@ function testsForMode(type: LintMode) {
       VideosHaveAltText,
       VideosAreSubtitled,
       TitleMeetsLengthCriteria,
+      ViewportDisablesTapDelay,
     ])
   );
   tests.set(

packages/linter/src/rules/ViewportDisablesTapDelay.ts

@@ -8,15 +8,17 @@ export class ViewportDisablesTapDelay extends Rule {
       return this.pass();
     }
     return viewport.attribs.content !== "width=device-width"
-      ? this.fail(`Viewport width not set to device width`)
+      ? this.warn(
+          `Viewport width is not set to device width: '<meta name="viewport" content="width=device-width">'`
+        )
       : this.pass();
   }
   meta() {
     return {
       url:
         "https://developers.google.com/web/updates/2013/12/300ms-tap-delay-gone-away",
       title:
-        "Set viewport width to the same as the device to disable touch delay causing FID.",
+        "Set viewport width to match the device to disable touch delay causing FID.",
       info: "",
     };
   }

packages/linter/tests/local.test.ts

@@ -610,7 +610,7 @@ describe(ViewportDisablesTapDelay.name, () => {
   });
 
   it(`${ViewportDisablesTapDelay.name} - Viewport causes Tap Delay`, async () => {
-    return assertFail(
+    return assertWarn(
       runLocalTest(
         ViewportDisablesTapDelay,
         `${__dirname}/local/ViewportDisablesTapDelay-2/source.html`