Add vue/block-tag-newline rule (#1328)

Author: ota-meshi

docs/rules/README.md

@@ -281,13 +281,14 @@ For example:
 ```json
 {
   "rules": {
-    "vue/component-name-in-template-casing": "error"
+    "vue/block-tag-newline": "error"
   }
 }
 ```
 
 | Rule ID | Description |    |
 |:--------|:------------|:---|
+| [vue/block-tag-newline](./block-tag-newline.md) | enforce line breaks after opening and before closing block-level tags | :wrench: |
 | [vue/component-name-in-template-casing](./component-name-in-template-casing.md) | enforce specific casing for the component naming style in template | :wrench: |
 | [vue/html-comment-content-newline](./html-comment-content-newline.md) | enforce unified line brake in HTML comments | :wrench: |
 | [vue/html-comment-content-spacing](./html-comment-content-spacing.md) | enforce unified spacing in HTML comments | :wrench: |

docs/rules/block-tag-newline.md

@@ -0,0 +1,161 @@
+---
+pageClass: rule-details
+sidebarDepth: 0
+title: vue/block-tag-newline
+description: enforce line breaks after opening and before closing block-level tags
+---
+# vue/block-tag-newline
+> enforce line breaks after opening and before closing block-level tags
+
+- :wrench: The `--fix` option on the [command line](https://eslint.org/docs/user-guide/command-line-interface#fixing-problems) can automatically fix some of the problems reported by this rule.
+
+## :book: Rule Details
+
+This rule enforces a line break (or no line break) after opening and before closing block tags.
+
+<eslint-code-block fix :rules="{'vue/block-tag-newline': ['error']}">
+
+```vue
+<!-- ✓ GOOD -->
+<template><input></template>
+
+<script>
+export default {}
+</script>
+```
+
+</eslint-code-block>
+
+<eslint-code-block fix :rules="{'vue/block-tag-newline': ['error']}">
+
+```vue
+<!-- ✗ BAD -->
+<template>
+<input></template>
+
+<script>
+export default {}</script>
+```
+
+</eslint-code-block>
+
+## :wrench: Options
+
+```json
+{
+  "vue/block-tag-newline": ["error", {
+    "singleline": "always" | "never" | "consistent" | "ignore",
+    "multiline": "always" | "never" | "consistent" | "ignore",
+    "maxEmptyLines": 0,
+    "blocks": {
+      "template": {
+        "singleline": "always" | "never" | "consistent" | "ignore",
+        "multiline": "always" | "never" | "consistent" | "ignore",
+        "maxEmptyLines": 0,
+      },
+      "script": {
+        "singleline": "always" | "never" | "consistent" | "ignore",
+        "multiline": "always" | "never" | "consistent" | "ignore",
+        "maxEmptyLines": 0,
+      },
+      "my-block": {
+        "singleline": "always" | "never" | "consistent" | "ignore",
+        "multiline": "always" | "never" | "consistent" | "ignore",
+        "maxEmptyLines": 0,
+      }
+    }
+  }]
+}
+```
+
+- `singleline` ... the configuration for single-line blocks.
+  - `"consistent"` ... (default) requires consistent usage of line breaks for each pair of tags. It reports an error if one tag in the pair has a linebreak inside it and the other tag does not.
+  - `"always"` ... require one line break after opening and before closing block tags.
+  - `"never"` ... disallow line breaks after opening and before closing block tags.
+- `multiline` ... the configuration for multi-line blocks.
+  - `"consistent"` ... requires consistent usage of line breaks for each pair of tags. It reports an error if one tag in the pair has a linebreak inside it and the other tag does not.
+  - `"always"` ... (default) require one line break after opening and before closing block tags.
+  - `"never"` ... disallow line breaks after opening and before closing block tags.
+- `maxEmptyLines` ... specifies the maximum number of empty lines allowed. default 0.
+- `blocks` ... specifies for each block name.
+
+### `{ "singleline": "never", "multiline": "always" }`
+
+<eslint-code-block fix :rules="{'vue/block-tag-newline': ['error', { 'singleline': 'never', 'multiline': 'always' }]}">
+
+```vue
+<!-- ✓ GOOD -->
+<template><input></template>
+
+<script>
+export default {
+}
+</script>
+```
+
+</eslint-code-block>
+
+<eslint-code-block fix :rules="{'vue/block-tag-newline': ['error', { 'singleline': 'never', 'multiline': 'always' }]}">
+
+```vue
+<!-- ✗ BAD -->
+<template>
+<input>
+</template>
+
+<script>export default {
+}</script>
+```
+
+</eslint-code-block>
+
+### `{ "singleline": "always", "multiline": "always", "maxEmptyLines": 1 }`
+
+<eslint-code-block fix :rules="{'vue/block-tag-newline': ['error', { 'singleline': 'always', 'multiline': 'always', 'maxEmptyLines': 1 }]}">
+
+```vue
+<!-- ✓ GOOD -->
+<template>
+
+<input>
+
+</template>
+
+<script>
+
+export default {
+}
+
+</script>
+```
+
+</eslint-code-block>
+
+<eslint-code-block fix :rules="{'vue/block-tag-newline': ['error', { 'singleline': 'always', 'multiline': 'always', 'maxEmptyLines': 1 }]}">
+
+```vue
+<!-- ✗ BAD -->
+<template>
+
+
+<input>
+
+
+</template>
+
+<script>
+
+
+export default {
+}
+
+
+</script>
+```
+
+</eslint-code-block>
+
+## :mag: Implementation
+
+- [Rule source](https://github.com/vuejs/eslint-plugin-vue/blob/master/lib/rules/block-tag-newline.js)
+- [Test source](https://github.com/vuejs/eslint-plugin-vue/blob/master/tests/lib/rules/block-tag-newline.js)

lib/configs/no-layout-rules.js

@@ -8,6 +8,7 @@ module.exports = {
     'vue/array-bracket-spacing': 'off',
     'vue/arrow-spacing': 'off',
     'vue/block-spacing': 'off',
+    'vue/block-tag-newline': 'off',
     'vue/brace-style': 'off',
     'vue/comma-dangle': 'off',
     'vue/comma-spacing': 'off',

lib/index.js

@@ -12,6 +12,7 @@ module.exports = {
     'attribute-hyphenation': require('./rules/attribute-hyphenation'),
     'attributes-order': require('./rules/attributes-order'),
     'block-spacing': require('./rules/block-spacing'),
+    'block-tag-newline': require('./rules/block-tag-newline'),
     'brace-style': require('./rules/brace-style'),
     camelcase: require('./rules/camelcase'),
     'comma-dangle': require('./rules/comma-dangle'),