From b5378edeebaba9a0c9e8b38e9dcbf20af24aa63e Mon Sep 17 00:00:00 2001
From: fisker Cheung <lionkay@gmail.com>
Date: Thu, 15 May 2025 11:27:22 +0800
Subject: [PATCH] Fix inconsistent member chain format (#17470)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
---
 changelog_unreleased/javascript/17470.md      | 22 +++++++++++++++++++
 src/language-js/print/member-chain.js         |  4 ++--
 .../__snapshots__/format.test.js.snap         | 16 ++++++++++++++
 tests/format/js/method-chain/issue-17457.js   |  1 +
 4 files changed, 41 insertions(+), 2 deletions(-)
 create mode 100644 changelog_unreleased/javascript/17470.md
 create mode 100644 tests/format/js/method-chain/issue-17457.js

diff --git a/changelog_unreleased/javascript/17470.md b/changelog_unreleased/javascript/17470.md
new file mode 100644
index 000000000..9d3907fd9
--- /dev/null
+++ b/changelog_unreleased/javascript/17470.md
@@ -0,0 +1,22 @@
+#### Fix inconsistent member chain format (#17470 by @fisker)
+
+<!-- prettier-ignore -->
+```jsx
+// Input
+s.get(u)?.trigger({ triggerKind: y.SignatureHelpTriggerKind.InvokeFooBarBaz123 });
+
+// Prettier stable (--parser=babel)
+s.get(u)?.trigger({
+  triggerKind: y.SignatureHelpTriggerKind.InvokeFooBarBaz123,
+});
+
+// Prettier stable (--parser=typescript)
+s
+  .get(u)
+  ?.trigger({ triggerKind: y.SignatureHelpTriggerKind.InvokeFooBarBaz123 });
+
+// Prettier main
+s.get(u)?.trigger({
+  triggerKind: y.SignatureHelpTriggerKind.InvokeFooBarBaz123,
+});
+```
diff --git a/src/language-js/print/member-chain.js b/src/language-js/print/member-chain.js
index 01037a0f0..57c6d1592 100644
--- a/src/language-js/print/member-chain.js
+++ b/src/language-js/print/member-chain.js
@@ -58,9 +58,9 @@ function printMemberChain(path, options, print) {
     );
   }
 
-  const { parent } = path;
   const isExpressionStatement =
-    !parent || parent.type === "ExpressionStatement";
+    (path.parent.type === "ChainExpression" ? path.grandparent : path.parent)
+      .type === "ExpressionStatement";
 
   // The first phase is to linearize the AST by traversing it down.
   //
diff --git a/tests/format/js/method-chain/__snapshots__/format.test.js.snap b/tests/format/js/method-chain/__snapshots__/format.test.js.snap
index 300367832..b6ba83d91 100644
--- a/tests/format/js/method-chain/__snapshots__/format.test.js.snap
+++ b/tests/format/js/method-chain/__snapshots__/format.test.js.snap
@@ -1249,6 +1249,22 @@ foo1(/叱叱叱/)
 ================================================================================
 `;
 
+exports[`issue-17457.js format 1`] = `
+====================================options=====================================
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+s.get(u)?.trigger({ triggerKind:   y.SignatureHelpTriggerKind.InvokeFooBarBaz123 });
+
+=====================================output=====================================
+s.get(u)?.trigger({
+  triggerKind: y.SignatureHelpTriggerKind.InvokeFooBarBaz123,
+});
+
+================================================================================
+`;
+
 exports[`logical.js format 1`] = `
 ====================================options=====================================
 parsers: ["babel", "flow", "typescript"]
diff --git a/tests/format/js/method-chain/issue-17457.js b/tests/format/js/method-chain/issue-17457.js
new file mode 100644
index 000000000..a7cf0457b
--- /dev/null
+++ b/tests/format/js/method-chain/issue-17457.js
@@ -0,0 +1 @@
+s.get(u)?.trigger({ triggerKind:   y.SignatureHelpTriggerKind.InvokeFooBarBaz123 });