⭐️New: Add vue/html-content-newline

docs/rules/html-content-newline.md

@@ -0,0 +1,86 @@
+# require or disallow a line break before and after html contents (vue/html-content-newline)
+
+- :wrench: The `--fix` option on the [command line](http://eslint.org/docs/user-guide/command-line-interface#fix) can automatically fix some of the problems reported by this rule.
+
+## :book: Rule Details
+
+This rule enforces a line break (or no line break) before and after html contents.
+
+
+:-1: Examples of **incorrect** code:
+
+```html
+<div
+  class="panel"
+>content</div>
+```
+
+:+1: Examples of **correct** code:
+
+```html
+<div class="panel">content</div>
+
+<div class="panel">
+  content
+</div>
+
+<div
+  class="panel"
+>
+  content
+</div>
+```
+
+
+## :wrench: Options
+
+```json
+{
+    "vue/html-content-newline": ["error", {
+        "singleline": "ignore",
+        "multiline": "always",
+        "ignoreNames": ["pre", "textarea"]
+    }]
+}
+```
+
+- `singleline` ... the configuration for single-line elements. It's a single-line element if startTag, endTag and contents are single-line.
+    - `"ignore"` ... Don't enforce line breaks style before and after the contents. This is the default.
+    - `"never"` ... disallow line breaks before and after the contents.
+    - `"always"` ... require one line break before and after the contents.
+- `multiline` ... the configuration for multiline elements. It's a multiline element if startTag, endTag or contents are multiline.
+    - `"ignore"` ... Don't enforce line breaks style before and after the contents.
+    - `"never"` ... disallow line breaks before and after the contents.
+    - `"always"` ... require one line break before and after the contents. This is the default.
+- `ignoreNames` ... the configuration for element names to ignore line breaks style.  
+    default `["pre", "textarea"]`
+
+
+:-1: Examples of **incorrect** code:
+
+```html
+/*eslint vue/html-content-newline: ["error", { "singleline": "always", "multiline": "never"}] */
+
+<div class="panel">content</div>
+
+<div
+  class="panel"
+>
+  content
+</div>
+```
+
+:+1: Examples of **correct** code:
+
+```html
+/*eslint vue/html-content-newline: ["error", { "singleline": "always", "multiline": "never"}] */
+
+<div class="panel">
+  content
+</div>
+
+<div
+  class="panel"
+>content</div>
+```
+

lib/index.js

@@ -12,6 +12,7 @@ module.exports = {
     'comment-directive': require('./rules/comment-directive'),
     'html-closing-bracket-newline': require('./rules/html-closing-bracket-newline'),
     'html-closing-bracket-spacing': require('./rules/html-closing-bracket-spacing'),
+    'html-content-newline': require('./rules/html-content-newline'),
     'html-end-tags': require('./rules/html-end-tags'),
     'html-indent': require('./rules/html-indent'),
     'html-quotes': require('./rules/html-quotes'),

lib/rules/html-content-newline.js

@@ -0,0 +1,147 @@
+/**
+ * @author Yosuke Ota
+ * See LICENSE file in root directory for full license.
+ */
+'use strict'
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+const utils = require('../utils')
+
+// ------------------------------------------------------------------------------
+// Helpers
+// ------------------------------------------------------------------------------
+
+function isMultiline (node, contentFirst, contentLast) {
+  if (node.startTag.loc.start.line !== node.startTag.loc.end.line ||
+    node.endTag.loc.start.line !== node.endTag.loc.end.line) {
+    // multiline tag
+    return true
+  }
+  if (contentFirst.loc.start.line < contentLast.loc.end.line) {
+    // multiline contents
+    return true
+  }
+  return false
+}
+
+function parseOptions (options) {
+  return Object.assign({
+    'singleline': 'ignore',
+    'multiline': 'always',
+    'ignoreNames': ['pre', 'textarea']
+  }, options)
+}
+
+function getPhrase (lineBreaks) {
+  switch (lineBreaks) {
+    case 0: return 'no line breaks'
+    case 1: return '1 line break'
+    default: return `${lineBreaks} line breaks`
+  }
+}
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      description: 'require or disallow a line break before and after html contents',
+      category: undefined,
+      url: 'https://github.com/vuejs/eslint-plugin-vue/blob/v5.0.0-beta.1/docs/rules/html-content-newline.md'
+    },
+    fixable: 'whitespace',
+    schema: [{
+      type: 'object',
+      properties: {
+        'singleline': { enum: ['ignore', 'always', 'never'] },
+        'multiline': { enum: ['ignore', 'always', 'never'] },
+        'ignoreNames': {
+          type: 'array',
+          items: { type: 'string' },
+          uniqueItems: true,
+          additionalItems: false
+        }
+      },
+      additionalProperties: false
+    }]
+  },
+
+  create (context) {
+    const options = parseOptions(context.options[0])
+    const template = context.parserServices.getTemplateBodyTokenStore && context.parserServices.getTemplateBodyTokenStore()
+
+    return utils.defineTemplateBodyVisitor(context, {
+      'VElement' (node) {
+        if (node.startTag.selfClosing || !node.endTag) {
+          // self closing
+          return
+        }
+        let target = node
+        while (target.type === 'VElement') {
+          if (options.ignoreNames.indexOf(target.name) >= 0) {
+          // ignore element name
+            return
+          }
+          target = target.parent
+        }
+        const getTokenOption = { includeComments: true, filter: (token) => token.type !== 'HTMLWhitespace' }
+        const contentFirst = template.getTokenAfter(node.startTag, getTokenOption)
+        const contentLast = template.getTokenBefore(node.endTag, getTokenOption)
+        const type = isMultiline(node, contentFirst, contentLast) ? options.multiline : options.singleline
+        if (type === 'ignore') {
+          // 'ignore' option
+          return
+        }
+        const beforeLineBreaks = contentFirst.loc.start.line - node.startTag.loc.end.line
+        const afterLineBreaks = node.endTag.loc.start.line - contentLast.loc.end.line
+        const expectedLineBreaks = type === 'always' ? 1 : 0
+        if (expectedLineBreaks !== beforeLineBreaks) {
+          context.report({
+            node: template.getLastToken(node.startTag),
+            loc: {
+              start: node.startTag.loc.end,
+              end: contentFirst.loc.start
+            },
+            message: `Expected {{expected}} after closing bracket of the "{{name}}" element, but {{actual}} found.`,
+            data: {
+              name: node.name,
+              expected: getPhrase(expectedLineBreaks),
+              actual: getPhrase(beforeLineBreaks)
+            },
+            fix (fixer) {
+              const range = [node.startTag.range[1], contentFirst.range[0]]
+              const text = '\n'.repeat(expectedLineBreaks)
+              return fixer.replaceTextRange(range, text)
+            }
+          })
+        }
+
+        if (expectedLineBreaks !== afterLineBreaks) {
+          context.report({
+            node: template.getFirstToken(node.endTag),
+            loc: {
+              start: contentLast.loc.end,
+              end: node.endTag.loc.start
+            },
+            message: 'Expected {{expected}} before opening bracket of the "{{name}}" element, but {{actual}} found.',
+            data: {
+              name: node.name,
+              expected: getPhrase(expectedLineBreaks),
+              actual: getPhrase(afterLineBreaks)
+            },
+            fix (fixer) {
+              const range = [contentLast.range[1], node.endTag.range[0]]
+              const text = '\n'.repeat(expectedLineBreaks)
+              return fixer.replaceTextRange(range, text)
+            }
+          })
+        }
+      }
+    })
+  }
+}