From 575391dae8d4994b6ddf0a794cbed8ae609e104f Mon Sep 17 00:00:00 2001
From: Lars Trieloff <trieloff@adobe.com>
Date: Thu, 18 Apr 2019 08:16:55 +0000
Subject: [PATCH] fix(embed): provide fallback with esi:remove when esi include
 fails

Until now, a failed ESI include would fail silently, without a possible fallback. This change falls
back to the markdown rendered as HTML in case the ESI does not work, giving at least an
approximation of the content created.

fixes #267
---
 src/utils/embed-handler.js | 11 +++++++++--
 test/testEmbedHandler.js   |  2 ++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/utils/embed-handler.js b/src/utils/embed-handler.js
index a8926597d..1faa0a1db 100644
--- a/src/utils/embed-handler.js
+++ b/src/utils/embed-handler.js
@@ -16,13 +16,20 @@
 const URI = require('uri-js');
 
 function embed({ EMBED_SERVICE }) {
-  return function handler(h, node) {
+  return function handler(h, node, _, handlechild) {
     const { url } = node;
     const props = {
       // prepend the embed service for absolute URLs
       src: (URI.parse(url).reference === 'absolute' ? EMBED_SERVICE : '') + url,
     };
-    const retval = h(node, 'esi:include', props);
+    const retval = [h(node, 'esi:include', props)];
+
+    if (node.children && node.children.length) {
+      const rem = h(node, 'esi:remove', {});
+      node.children.forEach(childnode => handlechild(h, childnode, node, rem));
+      retval.push(rem);
+    }
+
     return retval;
   };
 }
diff --git a/test/testEmbedHandler.js b/test/testEmbedHandler.js
index 60293c6c4..43fadd7a4 100644
--- a/test/testEmbedHandler.js
+++ b/test/testEmbedHandler.js
@@ -122,6 +122,7 @@ https://www.youtube.com/watch?v=KOxbO0EI4MA
     assert.equal(result.response.body, `<p>Hello World
 Here comes an embed.</p>
 
+
 <p><img src="easy.png" alt="Easy!" srcset="easy.png?width=480&amp;auto=webp 480w,easy.png?width=1384&amp;auto=webp 1384w,easy.png?width=2288&amp;auto=webp 2288w,easy.png?width=3192&amp;auto=webp 3192w,easy.png?width=4096&amp;auto=webp 4096w" sizes="100vw"></p>`);
   });
 
@@ -152,6 +153,7 @@ Here comes an embed.
     assert.equal(result.response.body, `<p>Hello World
 Here comes an embed.</p>
 <!-- bad ESI request: bad ESI request -->
+
 <p><img src="easy.png" alt="Easy!" srcset="easy.png?width=480&amp;auto=webp 480w,easy.png?width=1384&amp;auto=webp 1384w,easy.png?width=2288&amp;auto=webp 2288w,easy.png?width=3192&amp;auto=webp 3192w,easy.png?width=4096&amp;auto=webp 4096w" sizes="100vw"></p>`);
   });
 });