core(tags blocking first-paint): exclude script type=module (#3676)

* exclude script type='module' from render blocking warnings * pr fixes * add 404 sample module as script source * quick typo fix * fix smoketests
GoogleChrome · Nov 3, 2017 · 6ba5eb1 · 6ba5eb1
1 parent cfc2afe
commit 6ba5eb1
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Showing 4 changed files with 7 additions and 3 deletions.
diff --git a/lighthouse-cli/test/fixtures/dobetterweb/dbw_tester.html b/lighthouse-cli/test/fixtures/dobetterweb/dbw_tester.html
@@ -35,6 +35,9 @@
 <!-- FAIL: block rendering -->
 <script src="./dbw_tester.js"></script>
 
+<!-- PASS: 'modules' are deferred by default and don't block rendering -->
+<script type="module" src="./empty_module.js?delay=500"></script>
+
 <!-- FAIL(errors-in-console): exception thrown -->
 <script type="text/javascript">throw new Error('An error');</script>
 

diff --git a/lighthouse-cli/test/fixtures/dobetterweb/empty_module.js b/lighthouse-cli/test/fixtures/dobetterweb/empty_module.js
diff --git a/lighthouse-cli/test/smokehouse/dobetterweb/dbw-expectations.js b/lighthouse-cli/test/smokehouse/dobetterweb/dbw-expectations.js
@@ -37,13 +37,13 @@ module.exports = [
         extendedInfo: {
           value: {
             results: {
-              length: 15,
+              length: 16,
             },
           },
         },
         details: {
           items: {
-            length: 15,
+            length: 16,
           },
         },
       },

diff --git a/lighthouse-core/gather/gatherers/dobetterweb/tags-blocking-first-paint.js b/lighthouse-core/gather/gatherers/dobetterweb/tags-blocking-first-paint.js
@@ -32,7 +32,8 @@ function collectTagsThatBlockFirstPaint() {
           if (tag.tagName === 'SCRIPT') {
             return !tag.hasAttribute('async') &&
                 !tag.hasAttribute('defer') &&
-                !/^data:/.test(tag.src);
+                !/^data:/.test(tag.src) &&
+                tag.getAttribute('type') !== 'module';
           }
 
           // Filter stylesheet/HTML imports that block rendering.