Migrate postcss-nesting (#40)

* Migrate postcss-nesting

* Migrate postcss-nesting

Author: romainmenke

plugins/postcss-nesting/.bin/test-lint.js

@@ -1,17 +1,13 @@
 node_modules
-postcss-7-nesting
-postcss-8-nesting
 dist
 package-lock.json
 yarn.lock
 *.log*
 *.result.css
-.*
-!.bin
+*.result.css.map
 !.editorconfig
-!.github
 !.gitignore
-!.npmrc
 !.rollup.js
 !.tape.js
 !.travis.yml
+!.github

plugins/postcss-nesting/.bin/test-tape.js

@@ -0,0 +1,90 @@
+const mixinPluginRule = () => {
+	return {
+		postcssPlugin: 'mixin',
+		AtRule: {
+			mixin(node) {
+				node.replaceWith('& .in{ &.deep { color: blue; }}')
+			},
+		},
+	}
+}
+
+mixinPluginRule.postcss = true
+
+const mixinPluginRuleWithNesting = () => {
+	return {
+		postcssPlugin: 'mixin-with-nesting',
+		plugins: [mixinPluginRule(), require('./dist/index.cjs')()]
+	}
+}
+
+mixinPluginRuleWithNesting.postcss = true
+
+const mixinPluginDeclaration = () => {
+	return {
+		postcssPlugin: 'mixin',
+		AtRule: {
+			mixin(node) {
+				node.replaceWith('color: blue;')
+			},
+		},
+	}
+}
+
+mixinPluginDeclaration.postcss = true
+
+const mixinPluginDeclarationWithNesting = () => {
+	return {
+		postcssPlugin: 'mixin-with-nesting',
+		Once: () => {
+			throw new Error('bork');
+		},
+		plugins: [mixinPluginDeclaration(), require('./dist/index.cjs')()]
+	}
+}
+
+mixinPluginDeclarationWithNesting.postcss = true
+
+module.exports = {
+	'basic': {
+		message: 'supports basic usage',
+	},
+	'complex': {
+		message: 'supports complex entries',
+	},
+	'direct': {
+		message: 'supports direct usage',
+	},
+	'at-rule': {
+		message: 'supports at-rule usage',
+	},
+	'container': {
+		message: 'supports nested @container',
+	},
+	'document': {
+		message: 'supports nested @document',
+	},
+	'media': {
+		message: 'supports nested @media',
+	},
+	'supports': {
+		message: 'supports nested @supports',
+	},
+	'empty': {
+		message: 'removes empty rules',
+	},
+	'ignore': {
+		message: 'ignores invalid entries',
+	},
+	'mixin-declaration': {
+		message: 'supports other visitors (mixin declaration)',
+		plugin: mixinPluginDeclarationWithNesting
+	},
+	'mixin-rule': {
+		message: 'supports other visitors (mixin rule)',
+		plugin: mixinPluginRuleWithNesting
+	},
+	'spec-examples': {
+		message: 'supports all spec examples',
+	},
+};