From b73cfd992e8f87f03b29d20488195275f5f90f44 Mon Sep 17 00:00:00 2001
From: tbashiyy <40194351+tbashiyy@users.noreply.github.com>
Date: Mon, 4 Nov 2024 12:12:37 +0900
Subject: [PATCH] fix(linter): fix `is_method_call` with parentheses and chain
 expression (#7095)

I fixed `is_method_call` behavior in specific case below.

For example, when we use `is_method_call(call_expr, None,
Some(&["apply"]), Some(1), Some(1))` for
[`(a?.b.apply)(args)`](https://playground.oxc.rs/#eNpFjkEKg0AMRe+SVQviAdx057alN4gaZWBMJJmxFfHunVG0q+Qnn//fCi1UcMNH2ZQ4TX6531AHu0MBAtUKGjkPWzjgF6qgkQrwjsO5WysTXWIZG/GnCopsvegIVY/eaCtgQjXSnIjey+dNISo/YzDXUR25DU5S3+5OZqVknumFSmxHasrI7XtG2q+K89BKRwNl5iRGx653/xcHFV+n3gwwkzZiCf1g27YfdH1fTA==),
we cannot check correctly.

This is because we don't consider `call_expr` has parentheses and chain
expression.
---
 crates/oxc_linter/src/ast_util.rs                      | 10 ++++++++--
 .../oxc_linter/src/rules/unicorn/prefer_array_flat.rs  |  2 ++
 crates/oxc_linter/src/snapshots/prefer_array_flat.snap |  9 +++++++++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/crates/oxc_linter/src/ast_util.rs b/crates/oxc_linter/src/ast_util.rs
index 86355df6a..c9333d9b8 100644
--- a/crates/oxc_linter/src/ast_util.rs
+++ b/crates/oxc_linter/src/ast_util.rs
@@ -332,8 +332,14 @@ pub fn is_method_call<'a>(
         }
     }
 
-    let Some(member_expr) = call_expr.callee.without_parentheses().as_member_expression() else {
-        return false;
+    let callee_without_parentheses = call_expr.callee.without_parentheses();
+    let member_expr = match callee_without_parentheses {
+        match_member_expression!(Expression) => callee_without_parentheses.to_member_expression(),
+        Expression::ChainExpression(chain) => match chain.expression {
+            match_member_expression!(ChainElement) => chain.expression.to_member_expression(),
+            ChainElement::CallExpression(_) => return false,
+        },
+        _ => return false,
     };
 
     if let Some(objects) = objects {
diff --git a/crates/oxc_linter/src/rules/unicorn/prefer_array_flat.rs b/crates/oxc_linter/src/rules/unicorn/prefer_array_flat.rs
index a6a1c4a9b..c2d97c461 100644
--- a/crates/oxc_linter/src/rules/unicorn/prefer_array_flat.rs
+++ b/crates/oxc_linter/src/rules/unicorn/prefer_array_flat.rs
@@ -302,6 +302,7 @@ fn test() {
         r"array.flatMap(() => x)",
         r"array.flatMap((x, y) => x)",
         r"array.flatMap(x => y)",
+        r"(array?.flatMap)?.(x => y)",
         r"new array.reduce((a, b) => a.concat(b), [])",
         r"array.reduce",
         r"reduce((a, b) => a.concat(b), [])",
@@ -388,6 +389,7 @@ fn test() {
 
     let fail = vec![
         r"array.flatMap(x => x)",
+        r"(array?.flatMap)?.(x => x)",
         r"function foo(){return[].flatMap(x => x)}",
         r"foo.flatMap(x => x) instanceof Array",
         r"array.reduce((a, b) => a.concat(b), [])",
diff --git a/crates/oxc_linter/src/snapshots/prefer_array_flat.snap b/crates/oxc_linter/src/snapshots/prefer_array_flat.snap
index 4f154b9bb..6166f049e 100644
--- a/crates/oxc_linter/src/snapshots/prefer_array_flat.snap
+++ b/crates/oxc_linter/src/snapshots/prefer_array_flat.snap
@@ -1,5 +1,7 @@
 ---
 source: crates/oxc_linter/src/tester.rs
+assertion_line: 353
+snapshot_kind: text
 ---
   ⚠ eslint-plugin-unicorn(prefer-array-flat): Prefer Array#flat() over legacy techniques to flatten arrays.
    ╭─[prefer_array_flat.tsx:1:1]
@@ -8,6 +10,13 @@ source: crates/oxc_linter/src/tester.rs
    ╰────
   help: Call `.flat()` on the array instead.
 
+  ⚠ eslint-plugin-unicorn(prefer-array-flat): Prefer Array#flat() over legacy techniques to flatten arrays.
+   ╭─[prefer_array_flat.tsx:1:1]
+ 1 │ (array?.flatMap)?.(x => x)
+   · ──────────────────────────
+   ╰────
+  help: Call `.flat()` on the array instead.
+
   ⚠ eslint-plugin-unicorn(prefer-array-flat): Prefer Array#flat() over legacy techniques to flatten arrays.
    ╭─[prefer_array_flat.tsx:1:22]
  1 │ function foo(){return[].flatMap(x => x)}