From d272cbd1a116a07cb952ba36ba7bae1d3173e1ed Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@xwp.co>
Date: Fri, 14 Jul 2017 22:44:01 -0700
Subject: [PATCH 1/3] Prevent serializing block attributes to comment which
 match defaults

---
 blocks/api/serializer.js                                | 9 +++++++--
 blocks/api/test/serializer.js                           | 7 ++++++-
 blocks/library/text/index.js                            | 4 ++++
 blocks/test/fixtures/core__cover-image.serialized.html  | 2 +-
 blocks/test/fixtures/core__latest-posts.html            | 2 +-
 blocks/test/fixtures/core__latest-posts.json            | 2 +-
 blocks/test/fixtures/core__latest-posts.parsed.json     | 2 +-
 blocks/test/fixtures/core__latest-posts.serialized.html | 2 +-
 blocks/test/fixtures/core__text__align-right.json       | 3 ++-
 9 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/blocks/api/serializer.js b/blocks/api/serializer.js
index 9c56e2b703f2e1..438e143aa1ce98 100644
--- a/blocks/api/serializer.js
+++ b/blocks/api/serializer.js
@@ -1,7 +1,7 @@
 /**
  * External dependencies
  */
-import { isEmpty, reduce, isObject } from 'lodash';
+import { isEmpty, reduce, isObject, isEqual, pickBy } from 'lodash';
 import { html as beautifyHtml } from 'js-beautify';
 import classnames from 'classnames';
 
@@ -138,7 +138,12 @@ export function serializeBlock( block ) {
 		saveContent = block.originalContent;
 	}
 
-	const saveAttributes = getCommentAttributes( block.attributes, parseBlockAttributes( saveContent, blockType.attributes ) );
+	let saveAttributes = getCommentAttributes( block.attributes, parseBlockAttributes( saveContent, blockType.attributes ) );
+
+	// Remove attributes that are the same as the defaults.
+	if ( blockType.defaultAttributes ) {
+		saveAttributes = pickBy( saveAttributes, ( value, key ) => ! isEqual( value, blockType.defaultAttributes[ key ] ) );
+	}
 
 	if ( 'core/more' === blockName ) {
 		return `<!--more${ saveAttributes.text ? ` ${ saveAttributes.text }` : '' }-->${ saveAttributes.noTeaser ? '\n<!--noteaser-->' : '' }`;
diff --git a/blocks/api/test/serializer.js b/blocks/api/test/serializer.js
index 97dda9b7ea30a3..ae477c0e5e2306 100644
--- a/blocks/api/test/serializer.js
+++ b/blocks/api/test/serializer.js
@@ -181,6 +181,10 @@ describe( 'block serializer', () => {
 	describe( 'serialize()', () => {
 		it( 'should serialize the post content properly', () => {
 			const blockType = {
+				defaultAttributes: {
+					foo: true,
+					bar: false,
+				},
 				attributes: ( rawContent ) => {
 					return {
 						content: rawContent,
@@ -195,13 +199,14 @@ describe( 'block serializer', () => {
 				{
 					name: 'core/test-block',
 					attributes: {
+						foo: false,
 						content: 'Ribs & Chicken',
 						stuff: 'left & right -- but <not>',
 					},
 					isValid: true,
 				},
 			];
-			const expectedPostContent = '<!-- wp:core/test-block {"stuff":"left \\u0026 right \\u002d\\u002d but \\u003cnot\\u003e"} -->\n<p class="wp-block-test-block">Ribs & Chicken</p>\n<!-- /wp:core/test-block -->';
+			const expectedPostContent = '<!-- wp:core/test-block {"foo":false,"stuff":"left \\u0026 right \\u002d\\u002d but \\u003cnot\\u003e"} -->\n<p class="wp-block-test-block">Ribs & Chicken</p>\n<!-- /wp:core/test-block -->';
 
 			expect( serialize( blockList ) ).toEqual( expectedPostContent );
 		} );
diff --git a/blocks/library/text/index.js b/blocks/library/text/index.js
index 14b91331d218fd..3286a89d682a47 100644
--- a/blocks/library/text/index.js
+++ b/blocks/library/text/index.js
@@ -25,6 +25,10 @@ registerBlockType( 'core/text', {
 
 	category: 'common',
 
+	defaultAttributes: {
+		dropCap: false,
+	},
+
 	className: false,
 
 	attributes: {
diff --git a/blocks/test/fixtures/core__cover-image.serialized.html b/blocks/test/fixtures/core__cover-image.serialized.html
index e9643ec6638976..9a31a18f8cf4c3 100644
--- a/blocks/test/fixtures/core__cover-image.serialized.html
+++ b/blocks/test/fixtures/core__cover-image.serialized.html
@@ -1,4 +1,4 @@
-<!-- wp:core/cover-image {"hasBackgroundDim":true,"url":"https://cldup.com/uuUqE_dXzy.jpg"} -->
+<!-- wp:core/cover-image {"url":"https://cldup.com/uuUqE_dXzy.jpg"} -->
 <section class="wp-block-cover-image has-background-dim" style="background-image:url(https://cldup.com/uuUqE_dXzy.jpg);">
     <h2>Guten Berg!</h2>
 </section>
diff --git a/blocks/test/fixtures/core__latest-posts.html b/blocks/test/fixtures/core__latest-posts.html
index 99d215f58affad..d3128a66820632 100644
--- a/blocks/test/fixtures/core__latest-posts.html
+++ b/blocks/test/fixtures/core__latest-posts.html
@@ -1 +1 @@
-<!-- wp:core/latest-posts {"postsToShow":5,"displayPostDate":false} /-->
+<!-- wp:core/latest-posts {"postsToShow":5,"displayPostDate":true} /-->
diff --git a/blocks/test/fixtures/core__latest-posts.json b/blocks/test/fixtures/core__latest-posts.json
index 153471c7c68270..303d110f0f9215 100644
--- a/blocks/test/fixtures/core__latest-posts.json
+++ b/blocks/test/fixtures/core__latest-posts.json
@@ -6,7 +6,7 @@
         "attributes": {
             "columns": 3,
             "postsToShow": 5,
-            "displayPostDate": false,
+            "displayPostDate": true,
             "layout": "list"
         }
     }
diff --git a/blocks/test/fixtures/core__latest-posts.parsed.json b/blocks/test/fixtures/core__latest-posts.parsed.json
index ac3a8dba1cc674..c0b53e30ca56b6 100644
--- a/blocks/test/fixtures/core__latest-posts.parsed.json
+++ b/blocks/test/fixtures/core__latest-posts.parsed.json
@@ -3,7 +3,7 @@
         "blockName": "core/latest-posts",
         "attrs": {
             "postsToShow": 5,
-            "displayPostDate": false
+            "displayPostDate": true
         },
         "rawContent": ""
     },
diff --git a/blocks/test/fixtures/core__latest-posts.serialized.html b/blocks/test/fixtures/core__latest-posts.serialized.html
index fba664016ae3c6..ab37368489fdaf 100644
--- a/blocks/test/fixtures/core__latest-posts.serialized.html
+++ b/blocks/test/fixtures/core__latest-posts.serialized.html
@@ -1 +1 @@
-<!-- wp:core/latest-posts {"postsToShow":5,"displayPostDate":false,"layout":"list","columns":3} /-->
+<!-- wp:core/latest-posts {"displayPostDate":true} /-->
diff --git a/blocks/test/fixtures/core__text__align-right.json b/blocks/test/fixtures/core__text__align-right.json
index b3d85a9604391d..73496b8ab977a3 100644
--- a/blocks/test/fixtures/core__text__align-right.json
+++ b/blocks/test/fixtures/core__text__align-right.json
@@ -9,7 +9,8 @@
                 [
                     "... like this one, which is separate from the above and right aligned."
                 ]
-            ]
+            ],
+            "dropCap": false
         }
     }
 ]

From 35f81dd10a8b5bf1f92ccb8d4c21f56ab63e3c8f Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@xwp.co>
Date: Fri, 14 Jul 2017 22:44:35 -0700
Subject: [PATCH 2/3] Prevent Text block from getting false or empty className

---
 blocks/library/text/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/blocks/library/text/index.js b/blocks/library/text/index.js
index 3286a89d682a47..723ebcb20b0ef8 100644
--- a/blocks/library/text/index.js
+++ b/blocks/library/text/index.js
@@ -113,7 +113,7 @@ registerBlockType( 'core/text', {
 
 	save( { attributes } ) {
 		const { align, content, dropCap } = attributes;
-		const className = dropCap && 'has-drop-cap';
+		const className = dropCap ? 'has-drop-cap' : null;
 
 		if ( ! align ) {
 			return <p className={ className }>{ content }</p>;

From d6c8fd40614f9e75962ea6c9737fc79b1b6b8bf2 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@xwp.co>
Date: Fri, 28 Jul 2017 12:28:29 -0700
Subject: [PATCH 3/3] Use createBlock to define default attributes

---
 blocks/api/test/serializer.js | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/blocks/api/test/serializer.js b/blocks/api/test/serializer.js
index ae477c0e5e2306..9e80e5981c42e4 100644
--- a/blocks/api/test/serializer.js
+++ b/blocks/api/test/serializer.js
@@ -13,6 +13,7 @@ import serialize, {
 	serializeAttributes,
 } from '../serializer';
 import { getBlockTypes, registerBlockType, unregisterBlockType } from '../registration';
+import { createBlock } from '../';
 
 describe( 'block serializer', () => {
 	afterEach( () => {
@@ -195,20 +196,15 @@ describe( 'block serializer', () => {
 				},
 			};
 			registerBlockType( 'core/test-block', blockType );
-			const blockList = [
-				{
-					name: 'core/test-block',
-					attributes: {
-						foo: false,
-						content: 'Ribs & Chicken',
-						stuff: 'left & right -- but <not>',
-					},
-					isValid: true,
-				},
-			];
+
+			const block = createBlock( 'core/test-block', {
+				foo: false,
+				content: 'Ribs & Chicken',
+				stuff: 'left & right -- but <not>',
+			} );
 			const expectedPostContent = '<!-- wp:core/test-block {"foo":false,"stuff":"left \\u0026 right \\u002d\\u002d but \\u003cnot\\u003e"} -->\n<p class="wp-block-test-block">Ribs & Chicken</p>\n<!-- /wp:core/test-block -->';
 
-			expect( serialize( blockList ) ).toEqual( expectedPostContent );
+			expect( serialize( [ block ] ) ).toEqual( expectedPostContent );
 		} );
 	} );
 } );