fix(eslint-plugin): [prefer-optional-chan] allow typeof for avoiding …

…reference error
typescript-eslint · Feb 14, 2024 · 68c8ac8 · 68c8ac8
1 parent 6a875b4
commit 68c8ac8
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Showing 3 changed files with 54 additions and 1 deletion.
diff --git a/packages/eslint-plugin/src/rules/prefer-optional-chain-utils/gatherLogicalOperands.ts b/packages/eslint-plugin/src/rules/prefer-optional-chain-utils/gatherLogicalOperands.ts
@@ -3,6 +3,7 @@ import type {
   TSESTree,
 } from '@typescript-eslint/utils';
 import { AST_NODE_TYPES } from '@typescript-eslint/utils';
+import type { SourceCode } from '@typescript-eslint/utils/ts-eslint';
 import {
   isBigIntLiteralType,
   isBooleanLiteralType,
@@ -122,6 +123,7 @@ function isValidFalseBooleanCheckType(
 export function gatherLogicalOperands(
   node: TSESTree.LogicalExpression,
   parserServices: ParserServicesWithTypeInformation,
+  sourceCode: Readonly<SourceCode>,
   options: PreferOptionalChainOptions,
 ): {
   operands: Operand[];
@@ -157,7 +159,20 @@ export function gatherLogicalOperands(
             comparedExpression.type === AST_NODE_TYPES.UnaryExpression &&
             comparedExpression.operator === 'typeof'
           ) {
-            // typeof x === 'undefined'
+            const argument = comparedExpression.argument;
+            if (argument.type === AST_NODE_TYPES.Identifier) {
+              const reference = sourceCode
+                .getScope(argument)
+                .references.find(ref => ref.identifier.name === argument.name);
+
+              if (!reference?.resolved?.defs.length) {
+                // typeof window === 'undefined'
+                result.push({ type: OperandValidity.Invalid });
+                continue;
+              }
+            }
+
+            // typeof x.y === 'undefined'
             result.push({
               type: OperandValidity.Valid,
               comparedName: comparedExpression.argument,

diff --git a/packages/eslint-plugin/src/rules/prefer-optional-chain.ts b/packages/eslint-plugin/src/rules/prefer-optional-chain.ts
@@ -179,6 +179,7 @@ export default createRule<
         const { operands, newlySeenLogicals } = gatherLogicalOperands(
           node,
           parserServices,
+          context.sourceCode,
           options,
         );
 

diff --git a/packages/eslint-plugin/tests/rules/prefer-optional-chain/prefer-optional-chain.test.ts b/packages/eslint-plugin/tests/rules/prefer-optional-chain/prefer-optional-chain.test.ts
@@ -907,6 +907,7 @@ describe('hand-crafted cases', () => {
         declare const x: 0n | { a: string };
         !x || x.a;
       `,
+      "typeof globalThis !== 'undefined' && globalThis.Array();",
     ],
     invalid: [
       // two  errors
@@ -1915,6 +1916,42 @@ describe('hand-crafted cases', () => {
           },
         ],
       },
+      {
+        code: `
+          function foo(globalThis?: { Array: Function }) {
+            typeof globalThis !== 'undefined' && globalThis.Array();
+          }
+        `,
+        output: `
+          function foo(globalThis?: { Array: Function }) {
+            globalThis?.Array();
+          }
+        `,
+        errors: [
+          {
+            messageId: 'preferOptionalChain',
+          },
+        ],
+      },
+      {
+        code: `
+          typeof globalThis !== 'undefined' && globalThis.Array && globalThis.Array();
+        `,
+        output: null,
+        errors: [
+          {
+            messageId: 'preferOptionalChain',
+            suggestions: [
+              {
+                messageId: 'optionalChainSuggest',
+                output: `
+          typeof globalThis !== 'undefined' && globalThis.Array?.();
+        `,
+              },
+            ],
+          },
+        ],
+      },
     ],
   });
 });