Add support for v flag to regexp/negation rule (#560)

Author: ota-meshi

.changeset/heavy-rings-reply.md

@@ -0,0 +1,5 @@
+---
+"eslint-plugin-regexp": minor
+---
+
+Add support for v flag to `regexp/negation` rule

lib/rules/negation.ts

@@ -1,4 +1,4 @@
-import { toCharSet } from "regexp-ast-analysis"
+import { toCharSet, toUnicodeSet } from "regexp-ast-analysis"
 import type {
     EscapeCharacterSet,
     UnicodePropertyCharacterSet,
@@ -39,8 +39,18 @@ export default createRule("negation", {
                     if (element.type !== "CharacterSet") {
                         return
                     }
+                    if (element.kind === "property" && element.strings) {
+                        // Unicode property escape with property of strings.
+                        // Actually the pattern passing through this branch is an invalid pattern,
+                        // but it has to be checked because of the type guards.
+                        return
+                    }
 
-                    if (flags.ignoreCase && element.kind === "property") {
+                    if (
+                        flags.ignoreCase &&
+                        !flags.unicodeSets &&
+                        element.kind === "property"
+                    ) {
                         // The ignore case canonicalization affects negated
                         // Unicode property escapes in a weird way. In short,
                         // /\p{Foo}/i is not the same as /[^\P{Foo}]/i if
@@ -49,14 +59,9 @@ export default createRule("negation", {
                         // Note: This only affects Unicode property escapes.
                         // All other character sets are either case-invariant
                         // (/./, /\s/, /\d/) or inconsistent (/\w/).
-
-                        // FIXME: TS Error
-                        // @ts-expect-error -- FIXME
-                        const ccSet = toCharSet(ccNode, flags)
+                        const ccSet = toUnicodeSet(ccNode, flags)
 
                         const negatedElementSet = toCharSet(
-                            // FIXME: TS Error
-                            // @ts-expect-error -- FIXME
                             {
                                 ...element,
                                 negate: !element.negate,

tests/lib/rules/negation.ts

@@ -3,7 +3,7 @@ import rule from "../../../lib/rules/negation"
 
 const tester = new RuleTester({
     parserOptions: {
-        ecmaVersion: 2020,
+        ecmaVersion: "latest",
         sourceType: "module",
     },
 })
@@ -14,6 +14,8 @@ tester.run("negation", rule as any, {
         String.raw`/[^\d\s]/`,
         String.raw`/[^\p{ASCII}]/iu`,
         String.raw`/[^\P{Ll}]/iu`,
+        String.raw`/[\p{Basic_Emoji}]/v`,
+        String.raw`/[^\P{Lowercase_Letter}]/iu`,
     ],
     invalid: [
         {
@@ -140,5 +142,12 @@ tester.run("negation", rule as any, {
             output: null,
             errors: ["Unexpected negated character class. Use '\\W' instead."],
         },
+        {
+            code: String.raw`/[^\P{Lowercase_Letter}]/iv`,
+            output: String.raw`/\p{Lowercase_Letter}/iv`,
+            errors: [
+                "Unexpected negated character class. Use '\\p{Lowercase_Letter}' instead.",
+            ],
+        },
     ],
 })