Add regexp/prefer-named-capture-group rule (#330)

* Add `regexp/prefer-named-capture-group` rule

* Improved grammar

Author: RunDevelopment

README.md

@@ -170,6 +170,7 @@ The rules with the following star :star: are included in the `plugin:regexp/reco
 | [regexp/prefer-d](https://ota-meshi.github.io/eslint-plugin-regexp/rules/prefer-d.html) | enforce using `\d` | :star::wrench: |
 | [regexp/prefer-lookaround](https://ota-meshi.github.io/eslint-plugin-regexp/rules/prefer-lookaround.html) | prefer lookarounds over capturing group that do not replace | :wrench: |
 | [regexp/prefer-named-backreference](https://ota-meshi.github.io/eslint-plugin-regexp/rules/prefer-named-backreference.html) | enforce using named backreferences | :wrench: |
+| [regexp/prefer-named-capture-group](https://ota-meshi.github.io/eslint-plugin-regexp/rules/prefer-named-capture-group.html) | enforce using named capture groups |  |
 | [regexp/prefer-plus-quantifier](https://ota-meshi.github.io/eslint-plugin-regexp/rules/prefer-plus-quantifier.html) | enforce using `+` quantifier | :star::wrench: |
 | [regexp/prefer-question-quantifier](https://ota-meshi.github.io/eslint-plugin-regexp/rules/prefer-question-quantifier.html) | enforce using `?` quantifier | :star::wrench: |
 | [regexp/prefer-star-quantifier](https://ota-meshi.github.io/eslint-plugin-regexp/rules/prefer-star-quantifier.html) | enforce using `*` quantifier | :star::wrench: |

docs/rules/README.md

@@ -79,6 +79,7 @@ The rules with the following star :star: are included in the `plugin:regexp/reco
 | [regexp/prefer-d](./prefer-d.md) | enforce using `\d` | :star::wrench: |
 | [regexp/prefer-lookaround](./prefer-lookaround.md) | prefer lookarounds over capturing group that do not replace | :wrench: |
 | [regexp/prefer-named-backreference](./prefer-named-backreference.md) | enforce using named backreferences | :wrench: |
+| [regexp/prefer-named-capture-group](./prefer-named-capture-group.md) | enforce using named capture groups |  |
 | [regexp/prefer-plus-quantifier](./prefer-plus-quantifier.md) | enforce using `+` quantifier | :star::wrench: |
 | [regexp/prefer-question-quantifier](./prefer-question-quantifier.md) | enforce using `?` quantifier | :star::wrench: |
 | [regexp/prefer-star-quantifier](./prefer-star-quantifier.md) | enforce using `*` quantifier | :star::wrench: |

docs/rules/prefer-named-capture-group.md

@@ -0,0 +1,47 @@
+---
+pageClass: "rule-details"
+sidebarDepth: 0
+title: "regexp/prefer-named-capture-group"
+description: "enforce using named capture groups"
+---
+# regexp/prefer-named-capture-group
+
+> enforce using named capture groups
+
+- :exclamation: <badge text="This rule has not been released yet." vertical="middle" type="error"> ***This rule has not been released yet.*** </badge>
+
+## :book: Rule Details
+
+This rule reports capturing groups without a name.
+
+This rule is inspired by the [prefer-named-capture-group] rule. The positions of reports are improved over the core rule and arguments of `new RegExp()` are also checked.
+
+<eslint-code-block>
+
+```js
+/* eslint regexp/prefer-named-capture-group: "error" */
+
+/* ✓ GOOD */
+var foo = /(?<foo>ba+r)/;
+var foo = /\b(?:foo)+\b/;
+
+/* ✗ BAD */
+var foo = /\b(foo)+\b/;
+```
+
+</eslint-code-block>
+
+## :wrench: Options
+
+Nothing.
+
+## :books: Further reading
+
+- [prefer-named-capture-group]
+
+[prefer-named-capture-group]: https://eslint.org/docs/rules/prefer-named-capture-group
+
+## :mag: Implementation
+
+- [Rule source](https://github.com/ota-meshi/eslint-plugin-regexp/blob/master/lib/rules/prefer-named-capture-group.ts)
+- [Test source](https://github.com/ota-meshi/eslint-plugin-regexp/blob/master/tests/lib/rules/prefer-named-capture-group.ts)

lib/rules/prefer-named-capture-group.ts

@@ -0,0 +1,49 @@
+import type { RegExpVisitor } from "regexpp/visitor"
+import type { RegExpContext } from "../utils"
+import { createRule, defineRegexpVisitor } from "../utils"
+import { mention } from "../utils/mention"
+
+export default createRule("prefer-named-capture-group", {
+    meta: {
+        docs: {
+            description: "enforce using named capture groups",
+            category: "Stylistic Issues",
+            recommended: false,
+        },
+        schema: [],
+        messages: {
+            required:
+                "Capture group {{group}} should be converted to a named or non-capturing group.",
+        },
+        type: "suggestion",
+    },
+    create(context) {
+        /**
+         * Create visitor
+         */
+        function createVisitor(
+            regexpContext: RegExpContext,
+        ): RegExpVisitor.Handlers {
+            const { node, getRegexpLocation } = regexpContext
+
+            return {
+                onCapturingGroupEnter(cgNode) {
+                    if (cgNode.name === null) {
+                        context.report({
+                            node,
+                            loc: getRegexpLocation(cgNode),
+                            messageId: "required",
+                            data: {
+                                group: mention(cgNode),
+                            },
+                        })
+                    }
+                },
+            }
+        }
+
+        return defineRegexpVisitor(context, {
+            createVisitor,
+        })
+    },
+})

lib/utils/rules.ts

@@ -52,6 +52,7 @@ import preferD from "../rules/prefer-d"
 import preferEscapeReplacementDollarChar from "../rules/prefer-escape-replacement-dollar-char"
 import preferLookaround from "../rules/prefer-lookaround"
 import preferNamedBackreference from "../rules/prefer-named-backreference"
+import preferNamedCaptureGroup from "../rules/prefer-named-capture-group"
 import preferPlusQuantifier from "../rules/prefer-plus-quantifier"
 import preferPredefinedAssertion from "../rules/prefer-predefined-assertion"
 import preferQuantifier from "../rules/prefer-quantifier"
@@ -123,6 +124,7 @@ export const rules = [
     preferEscapeReplacementDollarChar,
     preferLookaround,
     preferNamedBackreference,
+    preferNamedCaptureGroup,
     preferPlusQuantifier,
     preferPredefinedAssertion,
     preferQuantifier,

tests/lib/rules/prefer-named-capture-group.ts

@@ -0,0 +1,26 @@
+import { RuleTester } from "eslint"
+import rule from "../../../lib/rules/prefer-named-capture-group"
+
+const tester = new RuleTester({
+    parserOptions: {
+        ecmaVersion: 2020,
+        sourceType: "module",
+    },
+})
+
+tester.run("prefer-named-capture-group", rule as any, {
+    valid: [
+        String.raw`/foo/`,
+        String.raw`/b(?:a(?:r))/`,
+        String.raw`/(?<foo>bar)/`,
+        String.raw`/(?=a)(?<=b)/`,
+    ],
+    invalid: [
+        {
+            code: String.raw`/(foo)/`,
+            errors: [
+                "Capture group '(foo)' should be converted to a named or non-capturing group.",
+            ],
+        },
+    ],
+})