Add AMP validation checking for Gutenberg blocks

.dev-lib

@@ -7,4 +7,5 @@ SKIP_ECHO_PATHS_SCOPE=1
 function after_wp_install {
     echo "Installing REST API..."
     svn export -q https://plugins.svn.wordpress.org/jetpack/trunk/ "$WP_CORE_DIR/src/wp-content/plugins/jetpack"
+    svn export -q https://plugins.svn.wordpress.org/gutenberg/trunk/ "$WP_CORE_DIR/src/wp-content/plugins/gutenberg"
 }

.eslintrc

@@ -0,0 +1,187 @@
+{
+	"root": true,
+	"extends": [
+		"wordpress"
+	],
+	"env": {
+		"browser": true
+	},
+	"globals": {
+		"wp": true,
+		"window": true,
+		"document": true
+	},
+	"settings": {
+		"react": {
+			"pragma": "wp"
+		}
+	},
+	"rules": {
+		"no-magic-numbers": [2, { "ignoreArrayIndexes": true, "ignore": [ -1, 0, 1 ] }],
+		"array-bracket-spacing": [
+			"error",
+			"always"
+		],
+		"brace-style": [
+			"error",
+			"1tbs"
+		],
+		"camelcase": [
+			"error",
+			{
+				"properties": "never"
+			}
+		],
+		"comma-dangle": [
+			"error",
+			"never"
+		],
+		"comma-spacing": "error",
+		"comma-style": "error",
+		"computed-property-spacing": [
+			"error",
+			"always"
+		],
+		"dot-notation": "error",
+		"eol-last": "error",
+		"eqeqeq": "error",
+		"func-call-spacing": "error",
+		"indent": [
+			"error",
+			"tab",
+			{
+				"SwitchCase": 1
+			}
+		],
+		"key-spacing": "error",
+		"keyword-spacing": "error",
+		"lines-around-comment": "off",
+		"no-alert": "error",
+		"no-bitwise": "error",
+		"no-caller": "error",
+		"no-console": "error",
+		"no-debugger": "error",
+		"no-dupe-args": "error",
+		"no-dupe-keys": "error",
+		"no-duplicate-case": "error",
+		"no-else-return": "error",
+		"no-eval": "error",
+		"no-extra-semi": "error",
+		"no-fallthrough": "error",
+		"no-lonely-if": "error",
+		"no-mixed-operators": "error",
+		"no-mixed-spaces-and-tabs": "error",
+		"no-multiple-empty-lines": [
+			"error",
+			{
+				"max": 1
+			}
+		],
+		"no-multi-spaces": "error",
+		"no-multi-str": "off",
+		"no-negated-in-lhs": "error",
+		"no-nested-ternary": "error",
+		"no-redeclare": "error",
+		"no-restricted-syntax": [
+			"error",
+			{
+				"selector": "CallExpression[callee.name=/^__|_n|_x$/]:not([arguments.0.type=/^Literal|BinaryExpression$/])",
+				"message": "Translate function arguments must be string literals."
+			},
+			{
+				"selector": "CallExpression[callee.name=/^_n|_x$/]:not([arguments.1.type=/^Literal|BinaryExpression$/])",
+				"message": "Translate function arguments must be string literals."
+			},
+			{
+				"selector": "CallExpression[callee.name=_nx]:not([arguments.2.type=/^Literal|BinaryExpression$/])",
+				"message": "Translate function arguments must be string literals."
+			}
+		],
+		"no-shadow": "error",
+		"no-undef": "error",
+		"no-undef-init": "error",
+		"no-unreachable": "error",
+		"no-unsafe-negation": "error",
+		"no-unused-expressions": "error",
+		"no-unused-vars": "error",
+		"no-useless-return": "error",
+		"no-whitespace-before-property": "error",
+		"object-curly-spacing": [
+			"error",
+			"always"
+		],
+		"padded-blocks": [
+			"error",
+			"never"
+		],
+		"quote-props": [
+			"error",
+			"as-needed"
+		],
+		"react/display-name": "off",
+		"react/no-children-prop": "off",
+		"react/prop-types": "off",
+		"semi": "error",
+		"semi-spacing": "error",
+		"space-before-blocks": [
+			"error",
+			"always"
+		],
+		"space-before-function-paren": [
+			"error",
+			{
+				"anonymous": "never",
+				"named": "never",
+				"asyncArrow": "always"
+			}
+		],
+		"space-in-parens": [
+			"error",
+			"always"
+		],
+		"space-infix-ops": [
+			"error",
+			{
+				"int32Hint": false
+			}
+		],
+		"space-unary-ops": [
+			"error",
+			{
+				"overrides": {
+					"!": true,
+					"yield": true
+				}
+			}
+		],
+		"valid-jsdoc": [
+			"error",
+			{
+				"prefer": {
+					"arg": "param",
+					"argument": "param",
+					"extends": "augments",
+					"returns": "return"
+				},
+				"preferType": {
+					"array": "Array",
+					"bool": "boolean",
+					"Boolean": "boolean",
+					"float": "number",
+					"Float": "number",
+					"int": "number",
+					"integer": "number",
+					"Integer": "number",
+					"Number": "number",
+					"object": "Object",
+					"String": "string",
+					"Void": "void"
+				},
+				"requireParamDescription": false,
+				"requireReturn": false
+			}
+		],
+		"valid-typeof": "error",
+		"yoda": "off"
+	}
+}

Gruntfile.js

@@ -1,5 +1,6 @@
 /* eslint-env node */
 /* jshint node:true */
+/* eslint-disable camelcase */
 
 module.exports = function( grunt ) {
 	'use strict';

assets/css/amp-post-meta-box.css

@@ -64,3 +64,16 @@
 		line-height: 280%;
 	}
 }
+
+.amp-block-validation-errors {
+	font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
+	font-size: 13px;
+	line-height: 1.5;
+}
+.amp-block-validation-errors .amp-block-validation-errors__summary {
+	margin: 0.5em 0;
+	padding: 2px;
+}
+.amp-block-validation-errors .amp-block-validation-errors__list {
+	padding-left: 2.5em;
+}