From a104a850f892181c42ad2fb2e8809f1331b9ee73 Mon Sep 17 00:00:00 2001
From: Anix <anik220798@gmail.com>
Date: Wed, 25 Mar 2020 19:18:32 +0000
Subject: [PATCH] fix: ignores iife for no-floating-promise (fixes #647)

---
 .../src/rules/no-floating-promises.ts         | 18 ++++++++++++
 .../tests/rules/no-floating-promises.test.ts  | 28 ++++++++++++++++---
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/packages/eslint-plugin/src/rules/no-floating-promises.ts b/packages/eslint-plugin/src/rules/no-floating-promises.ts
index c3ee7ffccf3c..2c5a41b10d65 100644
--- a/packages/eslint-plugin/src/rules/no-floating-promises.ts
+++ b/packages/eslint-plugin/src/rules/no-floating-promises.ts
@@ -12,6 +12,11 @@ type Options = [
 
 type MessageId = 'floating' | 'floatingVoid' | 'floatingFixVoid';
 
+const possibleIifeCalleType = new Set([
+  'FunctionExpression',
+  'ArrowFunctionExpression',
+]);
+
 export default util.createRule<Options, MessageId>({
   name: 'no-floating-promises',
   meta: {
@@ -54,6 +59,10 @@ export default util.createRule<Options, MessageId>({
       ExpressionStatement(node): void {
         const { expression } = parserServices.esTreeNodeToTSNodeMap.get(node);
 
+        if (isIife(node)) {
+          return;
+        }
+
         if (isUnhandledPromise(checker, expression)) {
           if (options.ignoreVoid) {
             context.report({
@@ -80,6 +89,15 @@ export default util.createRule<Options, MessageId>({
       },
     };
 
+    function isIife(node: ts.Node): Boolean {
+      if (node?.expression.type === 'CallExpression') {
+        if (possibleIifeCalleType.has(node?.expression?.callee.type)) {
+          return true;
+        }
+      }
+      return false;
+    }
+
     function isUnhandledPromise(
       checker: ts.TypeChecker,
       node: ts.Node,
diff --git a/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts b/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
index efdbf5e1a48c..10bafefa7cee 100644
--- a/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
@@ -251,6 +251,30 @@ async function test() {
   return returnsPromise();
 }
   `,
+    `
+(async () => {
+	await something();
+})();
+`,
+    `
+(async () => {
+	something();
+})();
+`,
+    '(async function foo(){})();',
+    `
+function foo(){
+  (async function bar() {
+  })()
+}
+`,
+    `
+   const foo = () => new Promise((res) => {
+          (async function(){
+              await res(1)
+            })()
+        })
+`,
   ],
 
   invalid: [
@@ -344,10 +368,6 @@ async function test() {
 }
 `,
       errors: [
-        {
-          line: 3,
-          messageId: 'floating',
-        },
         {
           line: 4,
           messageId: 'floating',