From a3cbe6e7862f1c8002cfe3dc624f89edec1e3ba5 Mon Sep 17 00:00:00 2001
From: Toru Nagashima <public@mysticatea.dev>
Date: Fri, 19 Jun 2020 07:35:23 +0900
Subject: [PATCH] update prefer-spread

---
 lib/rules/prefer-spread.js       |  8 ++----
 tests/lib/rules/prefer-spread.js | 46 ++++++++++++++++++++++++++++++--
 2 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/lib/rules/prefer-spread.js b/lib/rules/prefer-spread.js
index bcb0dc0dd4c1..d3c3c4d22972 100644
--- a/lib/rules/prefer-spread.js
+++ b/lib/rules/prefer-spread.js
@@ -18,17 +18,13 @@ const astUtils = require("./utils/ast-utils");
  */
 function isVariadicApplyCalling(node) {
     return (
-        node.callee.type === "MemberExpression" &&
-        node.callee.property.type === "Identifier" &&
-        node.callee.property.name === "apply" &&
-        node.callee.computed === false &&
+        astUtils.isSpecificMemberAccess(node.callee, null, "apply") &&
         node.arguments.length === 2 &&
         node.arguments[1].type !== "ArrayExpression" &&
         node.arguments[1].type !== "SpreadElement"
     );
 }
 
-
 /**
  * Checks whether or not `thisArg` is not changed by `.apply()`.
  * @param {ASTNode|null} expectedThis The node that is the owner of the applied function.
@@ -75,7 +71,7 @@ module.exports = {
                     return;
                 }
 
-                const applied = node.callee.object;
+                const applied = astUtils.skipChainExpression(astUtils.skipChainExpression(node.callee).object);
                 const expectedThis = (applied.type === "MemberExpression") ? applied.object : null;
                 const thisArg = node.arguments[0];
 
diff --git a/tests/lib/rules/prefer-spread.js b/tests/lib/rules/prefer-spread.js
index 580d7faeba9d..7f48d845f1b4 100644
--- a/tests/lib/rules/prefer-spread.js
+++ b/tests/lib/rules/prefer-spread.js
@@ -18,7 +18,7 @@ const { RuleTester } = require("../../../lib/rule-tester");
 
 const errors = [{ messageId: "preferSpread", type: "CallExpression" }];
 
-const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 6 } });
+const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 2020 } });
 
 ruleTester.run("prefer-spread", rule, {
     valid: [
@@ -39,7 +39,11 @@ ruleTester.run("prefer-spread", rule, {
         // ignores incomplete things.
         "foo.apply();",
         "obj.foo.apply();",
-        "obj.foo.apply(obj, ...args)"
+        "obj.foo.apply(obj, ...args)",
+
+        // Optional chaining
+        "(a?.b).c.foo.apply(a?.b.c, args);",
+        "a?.b.c.foo.apply((a?.b).c, args);"
     ],
     invalid: [
         {
@@ -73,6 +77,44 @@ ruleTester.run("prefer-spread", rule, {
         {
             code: "[].concat.apply([\n/*empty*/\n], args);",
             errors
+        },
+
+        // Optional chaining
+        {
+            code: "foo.apply?.(undefined, args);",
+            errors
+        },
+        {
+            code: "foo?.apply(undefined, args);",
+            errors
+        },
+        {
+            code: "foo?.apply?.(undefined, args);",
+            errors
+        },
+        {
+            code: "(foo?.apply)(undefined, args);",
+            errors
+        },
+        {
+            code: "(foo?.apply)?.(undefined, args);",
+            errors
+        },
+        {
+            code: "(obj?.foo).apply(obj, args);",
+            errors
+        },
+        {
+            code: "a?.b.c.foo.apply(a?.b.c, args);",
+            errors
+        },
+        {
+            code: "(a?.b.c).foo.apply(a?.b.c, args);",
+            errors
+        },
+        {
+            code: "(a?.b).c.foo.apply((a?.b).c, args);",
+            errors
         }
     ]
 });