From 42764b43f791b81998f935ecf25d009fecf6164b Mon Sep 17 00:00:00 2001
From: Toru Nagashima <star.ctor@gmail.com>
Date: Fri, 24 May 2019 20:40:01 +0900
Subject: [PATCH] Fix: make require-atomic-updates relax (fixes #11723)

---
 lib/rules/require-atomic-updates.js       | 40 ++++++++++++++++++++---
 tests/lib/rules/require-atomic-updates.js | 17 ++++++++++
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/lib/rules/require-atomic-updates.js b/lib/rules/require-atomic-updates.js
index 09d7670d819..2f5cd942744 100644
--- a/lib/rules/require-atomic-updates.js
+++ b/lib/rules/require-atomic-updates.js
@@ -5,6 +5,8 @@
  */
 "use strict";
 
+const { getPropertyName } = require("eslint-utils");
+
 /**
  * Make the map from identifiers to each reference.
  * @param {escope.Scope} scope The scope to get references.
@@ -24,16 +26,45 @@ function createReferenceMap(scope, outReferenceMap = new Map()) {
     return outReferenceMap;
 }
 
+/**
+ * Get the name of a given reference.
+ * The name contains property names if the reference is to access to properties. For example:
+ * - `foo` → `"foo"`
+ * - `foo.bar` → `"foo.bar"`
+ * - `foo.bar.baz` → `"foo.bar.baz"`
+ * @param {escope.Reference} reference The reference to get.
+ * @returns {string} The reference name.
+ */
+function getReferenceName(reference) {
+    const names = [reference.identifier.name];
+    let node = reference.identifier;
+
+    while (node) {
+        const t = node.parent.type;
+
+        if (t === "MemberExpression" && node.parent.object === node) {
+            names.push(getPropertyName(node.parent, reference.from) || "*");
+            node = node.parent;
+        } else {
+            break;
+        }
+    }
+
+    return names.join(".");
+}
+
 /**
  * Checks if an expression is a variable that can only be observed within the given function.
  * @param {escope.Variable} variable The variable to check
+ * @param {string} referenceName The reference name.
  * @returns {boolean} `true` if the variable is local to the given function, and is never referenced in a closure.
  */
-function isLocalVariableWithoutEscape(variable) {
+function isLocalVariableWithoutEscape(variable, referenceName) {
     const functionScope = variable.scope.variableScope;
 
-    return variable.references.every(reference =>
-        reference.from.variableScope === functionScope);
+    return variable.references
+        .filter(reference => getReferenceName(reference) === referenceName)
+        .every(reference => reference.from.variableScope === functionScope);
 }
 
 class SegmentInfo {
@@ -235,6 +266,7 @@ module.exports = {
                     return;
                 }
                 const variable = getVariable(reference);
+                const referenceName = getReferenceName(reference);
                 const writeExpr = getWriteExpr(reference);
 
                 // Add a fresh read variable.
@@ -248,7 +280,7 @@ module.exports = {
                  */
                 if (writeExpr &&
                     writeExpr.parent.right === writeExpr && // ← exclude variable declarations.
-                    !isLocalVariableWithoutEscape(variable)
+                    !isLocalVariableWithoutEscape(variable, referenceName)
                 ) {
                     let refs = assignmentReferences.get(writeExpr);
 
diff --git a/tests/lib/rules/require-atomic-updates.js b/tests/lib/rules/require-atomic-updates.js
index 1287c356fb2..9eb89f95168 100644
--- a/tests/lib/rules/require-atomic-updates.js
+++ b/tests/lib/rules/require-atomic-updates.js
@@ -129,6 +129,23 @@ ruleTester.run("require-atomic-updates", rule, {
                     await doElse();
                 }
             }
+        `,
+
+        // https://github.com/eslint/eslint/issues/11723
+        `
+            function get() { return {}; }
+            function update() {}
+            async function foo(bar) {
+                let oldBar = await get(bar.id);
+                let doIt = () => {
+                    bar.visible = true;
+                };
+                if (oldBar) {
+                    bar.installDate = oldBar.installDate;
+                } else {
+                    bar.installDate = new Date();
+                }
+            }
         `
     ],