fix: normalize parenthesized union and intersection member names

Author: azat-io

rules/sort-union-types.ts

@@ -32,6 +32,7 @@ import { generatePredefinedGroups } from '../utils/generate-predefined-groups'
 import { getEslintDisabledLines } from '../utils/get-eslint-disabled-lines'
 import { isNodeEslintDisabled } from '../utils/is-node-eslint-disabled'
 import { doesCustomGroupMatch } from '../utils/does-custom-group-match'
+import { computeNodeName } from './sort-union-types/compute-node-name'
 import { sortNodesByGroups } from '../utils/sort-nodes-by-groups'
 import { createEslintRule } from '../utils/create-eslint-rule'
 import { reportAllErrors } from '../utils/report-all-errors'
@@ -223,7 +224,10 @@ export function sortUnionOrIntersectionTypes<MessageIds extends string>({
           break
       }
 
-      let name = sourceCode.getText(type)
+      let name = computeNodeName({
+        sourceCode,
+        type,
+      })
 
       let predefinedGroups = generatePredefinedGroups({
         cache: cachedGroupsByModifiersAndSelectors,

rules/sort-union-types/compute-node-name.ts

@@ -0,0 +1,35 @@
+import type { TSESTree } from '@typescript-eslint/types'
+import type { TSESLint } from '@typescript-eslint/utils'
+
+import { AST_NODE_TYPES } from '@typescript-eslint/utils'
+
+/**
+ * Computes the name of a union/intersection member.
+ *
+ * Multi-line parenthesized unions/intersections can include leading `|` or `&`
+ * in raw source text, while formatter output often omits them. To keep sorting
+ * stable across both forms, the leading separator prefix is normalized.
+ *
+ * @param params - Parameters object.
+ * @param params.sourceCode - ESLint source code object for text extraction.
+ * @param params.type - Type node represented by the member text.
+ * @returns Normalized member text used for sorting and matching.
+ */
+export function computeNodeName({
+  sourceCode,
+  type,
+}: {
+  sourceCode: TSESLint.SourceCode
+  type: TSESTree.TypeNode
+}): string {
+  let name = sourceCode.getText(type)
+
+  if (
+    type.type !== AST_NODE_TYPES.TSUnionType &&
+    type.type !== AST_NODE_TYPES.TSIntersectionType
+  ) {
+    return name
+  }
+
+  return name.replace(/^\s*[&|]\s*/u, '')
+}

test/rules/sort-intersection-types.test.ts

@@ -3222,6 +3222,41 @@ describe('sort-intersection-types', () => {
         `,
       })
     })
+
+    it('handles parenthesized unions consistently with prettier', async () => {
+      await valid({
+        code: dedent`
+          type ImportExportType = (
+            | ts.ExportDeclaration
+            | ts.ImportDeclaration
+          ) & {
+            moduleSpecifier: ts.StringLiteral;
+          };
+        `,
+        options: [options],
+      })
+
+      await invalid({
+        output: dedent`
+          type ImportExportType = (
+            | ts.ExportDeclaration
+            | ts.ImportDeclaration
+          ) & {
+            moduleSpecifier: ts.StringLiteral;
+          };
+        `,
+        code: dedent`
+          type ImportExportType = {
+            moduleSpecifier: ts.StringLiteral;
+          } & (
+            | ts.ExportDeclaration
+            | ts.ImportDeclaration
+          );
+        `,
+        errors: [{ messageId: 'unexpectedIntersectionTypesOrder' }],
+        options: [options],
+      })
+    })
   })
 
   describe('line-length', () => {

test/rules/sort-union-types.test.ts

@@ -3231,6 +3231,41 @@ describe('sort-union-types', () => {
         `,
       })
     })
+
+    it('handles parenthesized intersections consistently with prettier', async () => {
+      await valid({
+        code: dedent`
+          type CombinedType =
+            | A
+            | (
+                & B
+                & C
+              )
+        `,
+        options: [options],
+      })
+
+      await invalid({
+        output: dedent`
+          type CombinedType =
+            | A
+            | (
+                & B
+                & C
+              )
+        `,
+        code: dedent`
+          type CombinedType =
+            | (
+                & B
+                & C
+              )
+            | A
+        `,
+        errors: [{ messageId: 'unexpectedUnionTypesOrder' }],
+        options: [options],
+      })
+    })
   })
 
   describe('line-length', () => {