From 2de6036ae8a9e27d2521eec3ff17a31677f0004f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Ku=CC=88hl?= <martin.kuehl@gmail.com>
Date: Wed, 27 Dec 2017 08:16:50 +0100
Subject: [PATCH 1/3] Ensure children are processed properly in async mode

Add a test that renders a non-blocking element including an actual
asynchronous child element.
We should ensure that elements of this kind are ordered and nested
properly.
---
 test/test_renderer.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/test/test_renderer.js b/test/test_renderer.js
index 05943ee..ed09325 100644
--- a/test/test_renderer.js
+++ b/test/test_renderer.js
@@ -42,6 +42,18 @@ describe("renderer", _ => {
 		done();
 	});
 
+	it("should support non-blocking mode", done => {
+		let { renderer, stream } = setup();
+
+		/* eslint-disable indent */
+		renderer.renderView(NonBlockingContainer, null, stream, { fragment: true }, _ => {
+			assert.equal(stream.read(),
+				"<div><p>…</p><p><i>lorem ipsum</i></p><p>…</p></div>");
+			done();
+		});
+		/* eslint-enable indent */
+	});
+
 	it("should detect non-blocking child elements in blocking mode", done => {
 		let { renderer, stream } = setup();
 

From afdb4b9b9062c1098a41a51a9ac4acbfa42037f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Ku=CC=88hl?= <martin.kuehl@gmail.com>
Date: Wed, 27 Dec 2017 10:38:17 +0100
Subject: [PATCH 2/3] Use recursion to process child element generators in
 async mode

Element generators can have acynchronous children in non-blocking mode,
in which case the their _siblings_ should only be processed _after_
the current child has executed its callback.
This is only relevant in non-blocking mode because in blocking mode
we are certain that the children have run their callbacks once they
have returned.
---
 src/html.js | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/html.js b/src/html.js
index bd90b2b..2766324 100644
--- a/src/html.js
+++ b/src/html.js
@@ -93,23 +93,31 @@ function processChildren(stream, children, options, callback) {
 			continue;
 		}
 
-		let { nonBlocking, log, _idRegistry } = options;
-		let generatorOptions = { nonBlocking, log, _idRegistry };
-		if(child.length !== 1) { // element generator -- XXX: brittle heuristic (arity)
-			child(stream, generatorOptions, callback);
-			continue;
-		}
-
-		// deferred child element
-		let fn = element => {
-			element(stream, generatorOptions, callback);
+		let _callback = function() {
+			let res = callback.apply(null, arguments);
 			let next = i + 1;
 			if(next < children.length) {
 				let remainder = children.slice(next);
 				processChildren(stream, remainder, options, callback);
 			}
+			return res;
 		};
 
+		let { nonBlocking, log, _idRegistry } = options;
+		let generatorOptions = { nonBlocking, log, _idRegistry };
+		if(child.length !== 1) { // element generator -- XXX: brittle heuristic (arity)
+			if(nonBlocking) {
+				child(stream, generatorOptions, _callback);
+				break;
+			} else {
+				child(stream, generatorOptions, callback);
+				continue;
+			}
+		}
+
+		// deferred child element
+		let fn = element => element(stream, generatorOptions, _callback);
+
 		if(!nonBlocking) { // ensure deferred child element is synchronous
 			let invoked = false;
 

From 58d7e99bfa43b942aa4e7a5985390d0cb6b8d9f8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Ku=CC=88hl?= <martin.kuehl@gmail.com>
Date: Wed, 27 Dec 2017 14:48:03 +0100
Subject: [PATCH 3/3] Use process.nextTick to reset our stack in non-blocking
 mode

---
 src/html.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/html.js b/src/html.js
index 2766324..8982ec7 100644
--- a/src/html.js
+++ b/src/html.js
@@ -98,7 +98,12 @@ function processChildren(stream, children, options, callback) {
 			let next = i + 1;
 			if(next < children.length) {
 				let remainder = children.slice(next);
-				processChildren(stream, remainder, options, callback);
+				if(nonBlocking) {
+					process.nextTick(_ =>
+						processChildren(stream, remainder, options, callback));
+				} else {
+					processChildren(stream, remainder, options, callback);
+				}
 			}
 			return res;
 		};