fix(eslint-plugin): [no-misused-promises] improve check union types (#…

…8534) * fix(eslint-plugin): [no-misused-promises] improve check union types * apply reviews
typescript-eslint · Feb 23, 2024 · 1458920 · 1458920
1 parent c1441c8
commit 1458920
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Showing 2 changed files with 24 additions and 6 deletions.
diff --git a/packages/eslint-plugin/src/rules/no-misused-promises.ts b/packages/eslint-plugin/src/rules/no-misused-promises.ts
@@ -674,10 +674,7 @@ function isVoidReturningFunctionType(
  */
 function returnsThenable(checker: ts.TypeChecker, node: ts.Node): boolean {
   const type = checker.getApparentType(checker.getTypeAtLocation(node));
-
-  if (anySignatureIsThenableType(checker, node, type)) {
-    return true;
-  }
-
-  return false;
+  return tsutils
+    .unionTypeParts(type)
+    .some(t => anySignatureIsThenableType(checker, node, t));
 }
diff --git a/packages/eslint-plugin/tests/rules/no-misused-promises.test.ts b/packages/eslint-plugin/tests/rules/no-misused-promises.test.ts
@@ -474,6 +474,11 @@ restTuple('Hello');
         };
       }
     `,
+    `
+declare function foo(cb: undefined | (() => void));
+declare const bar: undefined | (() => void);
+foo(bar);
+    `,
     // https://github.com/typescript-eslint/typescript-eslint/issues/6637
     {
       code: `
@@ -1227,5 +1232,21 @@ const test: ReturnsRecord = () => {
       `,
       errors: [{ line: 7, messageId: 'voidReturnProperty' }],
     },
+    {
+      code: `
+declare function foo(cb: undefined | (() => void));
+declare const bar: undefined | (() => Promise<void>);
+foo(bar);
+      `,
+      errors: [{ line: 4, messageId: 'voidReturnArgument' }],
+    },
+    {
+      code: `
+declare function foo(cb: string & (() => void));
+declare const bar: string & (() => Promise<void>);
+foo(bar);
+      `,
+      errors: [{ line: 4, messageId: 'voidReturnArgument' }],
+    },
   ],
 });