From d7247770886c619263482c3e083bed9f97b22688 Mon Sep 17 00:00:00 2001
From: Gareth Jones <Jones258@Gmail.com>
Date: Thu, 11 Nov 2021 19:17:17 +1300
Subject: [PATCH] fix(eslint-plugin): check optional chaining for floating
 promises (#4096)

---
 .../src/rules/no-floating-promises.ts         |  8 +-
 .../tests/rules/no-floating-promises.test.ts  | 80 +++++++++++++++++++
 2 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/packages/eslint-plugin/src/rules/no-floating-promises.ts b/packages/eslint-plugin/src/rules/no-floating-promises.ts
index 5687f08a06b..edd26225323 100644
--- a/packages/eslint-plugin/src/rules/no-floating-promises.ts
+++ b/packages/eslint-plugin/src/rules/no-floating-promises.ts
@@ -65,7 +65,13 @@ export default util.createRule<Options, MessageId>({
           return;
         }
 
-        if (isUnhandledPromise(checker, node.expression)) {
+        let expression = node.expression;
+
+        if (expression.type === AST_NODE_TYPES.ChainExpression) {
+          expression = expression.expression;
+        }
+
+        if (isUnhandledPromise(checker, expression)) {
           if (options.ignoreVoid) {
             context.report({
               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 e7dfe710f15..e9a63df2b5d 100644
--- a/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
@@ -334,6 +334,28 @@ async function test() {
   returnsPromise()?.finally(() => {});
   return returnsPromise();
 }
+    `,
+    `
+const doSomething = async (
+  obj1: { a?: { b?: { c?: () => Promise<void> } } },
+  obj2: { a?: { b?: { c: () => Promise<void> } } },
+  obj3: { a?: { b: { c?: () => Promise<void> } } },
+  obj4: { a: { b: { c?: () => Promise<void> } } },
+  obj5: { a?: () => { b?: { c?: () => Promise<void> } } },
+  obj6?: { a: { b: { c?: () => Promise<void> } } },
+  callback?: () => Promise<void>,
+): Promise<void> => {
+  await obj1.a?.b?.c?.();
+  await obj2.a?.b?.c();
+  await obj3.a?.b.c?.();
+  await obj4.a.b.c?.();
+  await obj5.a?.().b?.c?.();
+  await obj6?.a.b.c?.();
+
+  return callback?.();
+};
+
+void doSomething();
     `,
     // ignoreIIFE
     {
@@ -414,6 +436,64 @@ async function test() {
         },
       ],
     },
+    {
+      code: `
+const doSomething = async (
+  obj1: { a?: { b?: { c?: () => Promise<void> } } },
+  obj2: { a?: { b?: { c: () => Promise<void> } } },
+  obj3: { a?: { b: { c?: () => Promise<void> } } },
+  obj4: { a: { b: { c?: () => Promise<void> } } },
+  obj5: { a?: () => { b?: { c?: () => Promise<void> } } },
+  obj6?: { a: { b: { c?: () => Promise<void> } } },
+  callback?: () => Promise<void>,
+): Promise<void> => {
+  obj1.a?.b?.c?.();
+  obj2.a?.b?.c();
+  obj3.a?.b.c?.();
+  obj4.a.b.c?.();
+  obj5.a?.().b?.c?.();
+  obj6?.a.b.c?.();
+
+  callback?.();
+};
+
+doSomething();
+      `,
+      errors: [
+        {
+          line: 11,
+          messageId: 'floatingVoid',
+        },
+        {
+          line: 12,
+          messageId: 'floatingVoid',
+        },
+        {
+          line: 13,
+          messageId: 'floatingVoid',
+        },
+        {
+          line: 14,
+          messageId: 'floatingVoid',
+        },
+        {
+          line: 15,
+          messageId: 'floatingVoid',
+        },
+        {
+          line: 16,
+          messageId: 'floatingVoid',
+        },
+        {
+          line: 18,
+          messageId: 'floatingVoid',
+        },
+        {
+          line: 21,
+          messageId: 'floatingVoid',
+        },
+      ],
+    },
     {
       options: [{ ignoreVoid: true }],
       code: `