From 1729f9ea4d7b2945b2b701d72027fd4aace954cf Mon Sep 17 00:00:00 2001
From: Milos Djermanovic <milos.djermanovic@gmail.com>
Date: Fri, 16 Sep 2022 23:49:40 +0200
Subject: [PATCH] feat: account for `sourceType: "commonjs"` in the strict rule
 (#16308)

Fixes #16304
---
 lib/rules/strict.js       |  2 +-
 tests/lib/rules/strict.js | 46 ++++++++++++++++++++++++++++++++++++++-
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/lib/rules/strict.js b/lib/rules/strict.js
index e677c95e717..75bb561253e 100644
--- a/lib/rules/strict.js
+++ b/lib/rules/strict.js
@@ -105,7 +105,7 @@ module.exports = {
         if (ecmaFeatures.impliedStrict) {
             mode = "implied";
         } else if (mode === "safe") {
-            mode = ecmaFeatures.globalReturn ? "global" : "function";
+            mode = ecmaFeatures.globalReturn || context.languageOptions.sourceType === "commonjs" ? "global" : "function";
         }
 
         /**
diff --git a/tests/lib/rules/strict.js b/tests/lib/rules/strict.js
index e3ea705fe7e..2798bc8cd53 100644
--- a/tests/lib/rules/strict.js
+++ b/tests/lib/rules/strict.js
@@ -10,7 +10,8 @@
 //------------------------------------------------------------------------------
 
 const rule = require("../../../lib/rules/strict"),
-    { RuleTester } = require("../../../lib/rule-tester");
+    { RuleTester } = require("../../../lib/rule-tester"),
+    FlatRuleTester = require("../../../lib/rule-tester/flat-rule-tester");
 
 //------------------------------------------------------------------------------
 // Tests
@@ -659,3 +660,46 @@ ruleTester.run("strict", rule, {
         }
     ]
 });
+
+const flatRuleTester = new FlatRuleTester();
+
+// TODO: merge these tests into `ruleTester.run` once we switch to FlatRuleTester (when FlatRuleTester becomes RuleTester).
+flatRuleTester.run("strict", rule, {
+    valid: [
+        {
+            code: "'use strict'; module.exports = function identity (value) { return value; }",
+            languageOptions: {
+                sourceType: "commonjs"
+            }
+        },
+        {
+            code: "'use strict'; module.exports = function identity (value) { return value; }",
+            options: ["safe"],
+            languageOptions: {
+                sourceType: "commonjs"
+            }
+        }
+    ],
+
+    invalid: [
+        {
+            code: "module.exports = function identity (value) { return value; }",
+            options: ["safe"],
+            languageOptions: {
+                sourceType: "commonjs"
+            },
+            errors: [
+                { messageId: "global", line: 1 }
+            ]
+        },
+        {
+            code: "module.exports = function identity (value) { return value; }",
+            languageOptions: {
+                sourceType: "commonjs"
+            },
+            errors: [
+                { messageId: "global", line: 1 }
+            ]
+        }
+    ]
+});