From 9be5ffb72e2a542f2d8bea8f654c6fd5f3c32d85 Mon Sep 17 00:00:00 2001
From: Michal Zgliczynski <michal.zgliczynski@sonarsource.com>
Date: Mon, 18 Mar 2024 11:31:55 +0100
Subject: [PATCH 1/2] Make no-unused-collection not trigger if writing to
 elements of said collection

---
 src/rules/no-unused-collection.ts        |  2 +-
 tests/rules/no-unused-collection.test.ts | 14 ++++++++------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/rules/no-unused-collection.ts b/src/rules/no-unused-collection.ts
index fd00cb72..3a1e5e7b 100644
--- a/src/rules/no-unused-collection.ts
+++ b/src/rules/no-unused-collection.ts
@@ -186,7 +186,7 @@ function isElementWrite(statement: TSESTree.ExpressionStatement, ref: TSESLint.S
 function isMemberExpressionReference(lhs: TSESTree.Node, ref: TSESLint.Scope.Reference): boolean {
   return (
     lhs.type === 'MemberExpression' &&
-    (isReferenceTo(ref, lhs.object) || isMemberExpressionReference(lhs.object, ref))
+    (isReferenceTo(ref, lhs.object))
   );
 }
 
diff --git a/tests/rules/no-unused-collection.test.ts b/tests/rules/no-unused-collection.test.ts
index 6fc358e0..cd90085a 100644
--- a/tests/rules/no-unused-collection.test.ts
+++ b/tests/rules/no-unused-collection.test.ts
@@ -34,7 +34,7 @@ function invalidTest(code: string) {
   };
 }
 
-ruleTester.run('Primitive return types should be used.', rule, {
+ruleTester.run('Collection contents should be used', rule, {
   valid: [
     {
       code: `
@@ -169,6 +169,13 @@ ruleTester.run('Primitive return types should be used.', rule, {
     {
       code: `export const collection = new Map()`,
     },
+    {
+      code: `
+        const a = {foo: false};
+        const xs = [a];
+        xs[0].foo = true;
+      `,
+    },
   ],
   invalid: [
     {
@@ -197,11 +204,6 @@ ruleTester.run('Primitive return types should be used.', rule, {
           arrayConstructor[1] = 42;
       }
       `),
-    invalidTest(`function nok2_1() {
-          let arrayConstructor = new Array(); // Noncompliant
-          arrayConstructor[1][2] = 42;
-      }
-      `),
     invalidTest(`function nok3() {
           let arrayWithoutNew = Array(); // Noncompliant
           arrayWithoutNew[1] = 42;

From f3c5aecd3531642c819c51e3b5834b68dc0ae9f4 Mon Sep 17 00:00:00 2001
From: Michal Zgliczynski <michal.zgliczynski@sonarsource.com>
Date: Mon, 18 Mar 2024 15:45:19 +0100
Subject: [PATCH 2/2] format

---
 src/rules/no-unused-collection.ts | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/rules/no-unused-collection.ts b/src/rules/no-unused-collection.ts
index 3a1e5e7b..949d83fe 100644
--- a/src/rules/no-unused-collection.ts
+++ b/src/rules/no-unused-collection.ts
@@ -184,10 +184,7 @@ function isElementWrite(statement: TSESTree.ExpressionStatement, ref: TSESLint.S
 }
 
 function isMemberExpressionReference(lhs: TSESTree.Node, ref: TSESLint.Scope.Reference): boolean {
-  return (
-    lhs.type === 'MemberExpression' &&
-    (isReferenceTo(ref, lhs.object))
-  );
+  return lhs.type === 'MemberExpression' && isReferenceTo(ref, lhs.object);
 }
 
 function isIdentifier(node: TSESTree.Node, ...values: string[]): node is TSESTree.Identifier {