feat(lines-before-block): add new rule; fixes #1209

BREAKING CHANGE:

Adds new rule to recommended

.README/README.md

@@ -247,6 +247,7 @@ non-default-recommended fixer).
 |:heavy_check_mark:|:wrench:|[empty-tags](./docs/rules/empty-tags.md#readme)|Checks tags that are expected to be empty (e.g., `@abstract` or `@async`), reporting if they have content|
 |:heavy_check_mark:||[implements-on-classes](./docs/rules/implements-on-classes.md#readme)|Prohibits use of `@implements` on non-constructor functions (to enforce the tag only being used on classes/constructors)|
 |||[informative-docs](./docs/rules/informative-docs.md#readme)|Reports on JSDoc texts that serve only to restate their attached name.|
+|:heavy_check_mark:||[lines-before-block](./docs/rules/lines-before-block.md#readme)|Enforces minimum number of newlines before JSDoc comment blocks|
 |||[match-description](./docs/rules/match-description.md#readme)|Defines customizable regular expression rules for your tag descriptions|
 ||:wrench:|[match-name](./docs/rules/match-name.md#readme)|Reports the name portion of a JSDoc tag if matching or not matching a given regular expression|
 |:heavy_check_mark:|:wrench:|[multiline-blocks](./docs/rules/multiline-blocks.md#readme)|Controls how and whether jsdoc blocks can be expressed as single or multiple line blocks|

.README/rules/lines-before-block.md

@@ -0,0 +1,37 @@
+# `lines-before-block`
+
+This rule enforces minimum number of newlines before JSDoc comment blocks
+(except at the beginning of a file).
+
+## Options
+
+### `lines`
+
+The minimum number of lines to require. Defaults to 1.
+
+### `ignoreSameLine`
+
+This option excludes cases where the JSDoc block occurs on the same line as a
+preceding code or comment. Defaults to `true`.
+
+### `excludedTags`
+
+An array of tags whose presence in the JSDoc block will prevent the
+application of the rule. Defaults to `['type']` (i.e., if `@type` is present,
+lines before the block will not be added).
+
+|||
+|---|---|
+|Context|everywhere|
+|Tags|N/A|
+|Recommended|true|
+|Settings||
+|Options|`excludedTags`, `ignoreSameLine`, `lines`|
+
+## Failing examples
+
+<!-- assertions-failing linesBeforeBlock -->
+
+## Passing examples
+
+<!-- assertions-passing linesBeforeBlock -->

README.md

@@ -277,6 +277,7 @@ non-default-recommended fixer).
 |:heavy_check_mark:|:wrench:|[empty-tags](./docs/rules/empty-tags.md#readme)|Checks tags that are expected to be empty (e.g., `@abstract` or `@async`), reporting if they have content|
 |:heavy_check_mark:||[implements-on-classes](./docs/rules/implements-on-classes.md#readme)|Prohibits use of `@implements` on non-constructor functions (to enforce the tag only being used on classes/constructors)|
 |||[informative-docs](./docs/rules/informative-docs.md#readme)|Reports on JSDoc texts that serve only to restate their attached name.|
+|:heavy_check_mark:||[lines-before-block](./docs/rules/lines-before-block.md#readme)|Enforces minimum number of newlines before JSDoc comment blocks|
 |||[match-description](./docs/rules/match-description.md#readme)|Defines customizable regular expression rules for your tag descriptions|
 ||:wrench:|[match-name](./docs/rules/match-name.md#readme)|Reports the name portion of a JSDoc tag if matching or not matching a given regular expression|
 |:heavy_check_mark:|:wrench:|[multiline-blocks](./docs/rules/multiline-blocks.md#readme)|Controls how and whether jsdoc blocks can be expressed as single or multiple line blocks|

docs/rules/lines-before-block.md

@@ -0,0 +1,150 @@
+<a name="user-content-lines-before-block"></a>
+<a name="lines-before-block"></a>
+# <code>lines-before-block</code>
+
+This rule enforces minimum number of newlines before JSDoc comment blocks
+(except at the beginning of a file).
+
+<a name="user-content-lines-before-block-options"></a>
+<a name="lines-before-block-options"></a>
+## Options
+
+<a name="user-content-lines-before-block-options-lines"></a>
+<a name="lines-before-block-options-lines"></a>
+### <code>lines</code>
+
+The minimum number of lines to require. Defaults to 1.
+
+<a name="user-content-lines-before-block-options-ignoresameline"></a>
+<a name="lines-before-block-options-ignoresameline"></a>
+### <code>ignoreSameLine</code>
+
+This option excludes cases where the JSDoc block occurs on the same line as a
+preceding code or comment. Defaults to `true`.
+
+<a name="user-content-lines-before-block-options-excludedtags"></a>
+<a name="lines-before-block-options-excludedtags"></a>
+### <code>excludedTags</code>
+
+An array of tags whose presence in the JSDoc block will prevent the
+application of the rule. Defaults to `['type']` (i.e., if `@type` is present,
+lines before the block will not be added).
+
+|||
+|---|---|
+|Context|everywhere|
+|Tags|N/A|
+|Recommended|true|
+|Settings||
+|Options|`excludedTags`, `ignoreSameLine`, `lines`|
+
+<a name="user-content-lines-before-block-failing-examples"></a>
+<a name="lines-before-block-failing-examples"></a>
+## Failing examples
+
+The following patterns are considered problems:
+
+````ts
+someCode;
+/**
+ *
+ */
+// Message: Required 1 line(s) before JSDoc block
+
+someCode; /**
+ *
+ */
+// "jsdoc/lines-before-block": ["error"|"warn", {"ignoreSameLine":false}]
+// Message: Required 1 line(s) before JSDoc block
+
+someCode; /** */
+// "jsdoc/lines-before-block": ["error"|"warn", {"ignoreSameLine":false}]
+// Message: Required 1 line(s) before JSDoc block
+
+someCode;
+/**
+ *
+ */
+// "jsdoc/lines-before-block": ["error"|"warn", {"lines":2}]
+// Message: Required 2 line(s) before JSDoc block
+
+// Some comment
+/**
+ *
+ */
+// Message: Required 1 line(s) before JSDoc block
+
+/* Some comment */
+/**
+ *
+ */
+// Message: Required 1 line(s) before JSDoc block
+
+/**
+ * Some comment
+ */
+/**
+ *
+ */
+// Message: Required 1 line(s) before JSDoc block
+````
+
+
+
+<a name="user-content-lines-before-block-passing-examples"></a>
+<a name="lines-before-block-passing-examples"></a>
+## Passing examples
+
+The following patterns are not considered problems:
+
+````ts
+/**
+*
+*/
+
+someCode;
+
+/**
+ *
+ */
+
+someCode;
+
+
+/**
+ *
+ */
+// "jsdoc/lines-before-block": ["error"|"warn", {"lines":2}]
+
+// Some comment
+
+/**
+ *
+ */
+
+/* Some comment */
+
+/**
+ *
+ */
+
+/**
+ * Some comment
+ */
+
+/**
+ *
+ */
+
+someCode; /** */
+
+const a = {
+  someProp: /** @type {SomeCast} */ (someVal)
+};
+
+const a = /** @lends SomeClass */ {
+  someProp: (someVal)
+};
+// "jsdoc/lines-before-block": ["error"|"warn", {"excludedTags":["lends"],"ignoreSameLine":false}]
+````
+

src/index.js

@@ -15,6 +15,7 @@ import emptyTags from './rules/emptyTags.js';
 import implementsOnClasses from './rules/implementsOnClasses.js';
 import importsAsDependencies from './rules/importsAsDependencies.js';
 import informativeDocs from './rules/informativeDocs.js';
+import linesBeforeBlock from './rules/linesBeforeBlock.js';
 import matchDescription from './rules/matchDescription.js';
 import matchName from './rules/matchName.js';
 import multilineBlocks from './rules/multilineBlocks.js';
@@ -92,6 +93,7 @@ const index = {
     'implements-on-classes': implementsOnClasses,
     'imports-as-dependencies': importsAsDependencies,
     'informative-docs': informativeDocs,
+    'lines-before-block': linesBeforeBlock,
     'match-description': matchDescription,
     'match-name': matchName,
     'multiline-blocks': multilineBlocks,
@@ -167,6 +169,7 @@ const createRecommendedRuleset = (warnOrError, flatName) => {
       'jsdoc/implements-on-classes': warnOrError,
       'jsdoc/imports-as-dependencies': 'off',
       'jsdoc/informative-docs': 'off',
+      'jsdoc/lines-before-block': warnOrError,
       'jsdoc/match-description': 'off',
       'jsdoc/match-name': 'off',
       'jsdoc/multiline-blocks': warnOrError,

src/rules/linesBeforeBlock.js

@@ -0,0 +1,101 @@
+import iterateJsdoc from '../iterateJsdoc.js';
+
+export default iterateJsdoc(({
+  context,
+  jsdocNode,
+  sourceCode,
+  report,
+  utils,
+}) => {
+  const {
+    lines = 1,
+    ignoreSameLine = true,
+    excludedTags = ['type']
+  } = context.options[0] || {};
+
+  if (utils.hasATag(excludedTags)) {
+    return;
+  }
+
+  const tokensBefore = sourceCode.getTokensBefore(jsdocNode, {includeComments: true});
+  const tokenBefore = tokensBefore.slice(-1)[0];
+  if (!tokenBefore) {
+    return;
+  }
+
+  if (tokenBefore.loc?.end?.line + lines >=
+    /** @type {number} */
+      (jsdocNode.loc?.start?.line)
+    ) {
+    const startLine = jsdocNode.loc?.start?.line;
+    const sameLine = tokenBefore.loc?.end?.line === startLine;
+
+    if (sameLine && ignoreSameLine) {
+      return;
+    }
+
+    /** @type {import('eslint').Rule.ReportFixer} */
+    const fix = (fixer) => {
+      let indent = '';
+      if (sameLine) {
+        const spaceDiff = /** @type {number} */ (jsdocNode.loc?.start?.column) -
+          /** @type {number} */ (tokenBefore.loc?.end?.column);
+        // @ts-expect-error Should be a comment
+        indent = /** @type {import('estree').Comment} */ (
+          jsdocNode
+        ).value.match(/^\*\n([ \t]*) \*/)?.[1]?.slice(spaceDiff);
+        if (!indent) {
+          /** @type {import('eslint').AST.Token|import('estree').Comment|undefined} */
+          let tokenPrior = tokenBefore;
+          let startColumn;
+          while (tokenPrior && tokenPrior?.loc?.start?.line === startLine) {
+            startColumn = tokenPrior.loc?.start?.column;
+            tokenPrior = tokensBefore.pop();
+          }
+          indent = ' '.repeat(
+            /* c8 ignore next */
+            /** @type {number} */ (startColumn ? startColumn - 1 : 0)
+          );
+        }
+      }
+
+      return fixer.insertTextAfter(
+        /** @type {import('eslint').AST.Token} */
+        (tokenBefore),
+        '\n'.repeat(lines) +
+        (sameLine ? '\n' + indent : '')
+      );
+    };
+    report(`Required ${lines} line(s) before JSDoc block`, fix);
+  }
+}, {
+  iterateAllJsdocs: true,
+  meta: {
+    fixable: 'code',
+    docs: {
+      description: 'Enforces minimum number of newlines before JSDoc comment blocks',
+      url: 'https://github.com/gajus/eslint-plugin-jsdoc/blob/main/docs/rules/lines-before-block.md#repos-sticky-header',
+    },
+    schema: [
+      {
+        additionalProperties: false,
+        properties: {
+          excludedTags: {
+            type: 'array',
+            items: {
+              type: 'string'
+            }
+          },
+          ignoreSameLine: {
+            type: 'boolean',
+          },
+          lines: {
+            type: 'integer'
+          }
+        },
+        type: 'object',
+      },
+    ],
+    type: 'suggestion',
+  },
+});