From 34786b65f73e738c4531ef4c690f1ab1f179c6cc Mon Sep 17 00:00:00 2001
From: Patrick Ahmetovic <patrick.ahmetovic@gmail.com>
Date: Sat, 10 Apr 2021 17:21:38 +0200
Subject: [PATCH] Rework & store variables in segmentInfo instead of variable
 names

---
 lib/rules/require-atomic-updates.js       | 46 +++++++++++------------
 tests/lib/rules/require-atomic-updates.js | 15 ++++++++
 2 files changed, 36 insertions(+), 25 deletions(-)

diff --git a/lib/rules/require-atomic-updates.js b/lib/rules/require-atomic-updates.js
index a77b01c11642..a8e5007de172 100644
--- a/lib/rules/require-atomic-updates.js
+++ b/lib/rules/require-atomic-updates.js
@@ -86,42 +86,42 @@ class SegmentInfo {
      * @returns {void}
      */
     initialize(segment) {
-        const outdatedReadVariableNames = new Set();
-        const freshReadVariableNames = new Set();
+        const outdatedReadVariables = new Set();
+        const freshReadVariables = new Set();
 
         for (const prevSegment of segment.prevSegments) {
             const info = this.info.get(prevSegment);
 
             if (info) {
-                info.outdatedReadVariableNames.forEach(Set.prototype.add, outdatedReadVariableNames);
-                info.freshReadVariableNames.forEach(Set.prototype.add, freshReadVariableNames);
+                info.outdatedReadVariables.forEach(Set.prototype.add, outdatedReadVariables);
+                info.freshReadVariables.forEach(Set.prototype.add, freshReadVariables);
             }
         }
 
-        this.info.set(segment, { outdatedReadVariableNames, freshReadVariableNames });
+        this.info.set(segment, { outdatedReadVariables, freshReadVariables });
     }
 
     /**
      * Mark a given variable as read on given segments.
      * @param {PathSegment[]} segments The segments that it read the variable on.
-     * @param {string} variableName The variable name to be read.
+     * @param {Variable} variable The variable to be read.
      * @returns {void}
      */
-    markAsRead(segments, variableName) {
+    markAsRead(segments, variable) {
         for (const segment of segments) {
             const info = this.info.get(segment);
 
             if (info) {
-                info.freshReadVariableNames.add(variableName);
+                info.freshReadVariables.add(variable);
 
                 // If a variable is freshly read again, then it's no more out-dated.
-                info.outdatedReadVariableNames.delete(variableName);
+                info.outdatedReadVariables.delete(variable);
             }
         }
     }
 
     /**
-     * Move `freshReadVariableNames` to `outdatedReadVariableNames`.
+     * Move `freshReadVariables` to `outdatedReadVariables`.
      * @param {PathSegment[]} segments The segments to process.
      * @returns {void}
      */
@@ -130,8 +130,8 @@ class SegmentInfo {
             const info = this.info.get(segment);
 
             if (info) {
-                info.freshReadVariableNames.forEach(Set.prototype.add, info.outdatedReadVariableNames);
-                info.freshReadVariableNames.clear();
+                info.freshReadVariables.forEach(Set.prototype.add, info.outdatedReadVariables);
+                info.freshReadVariables.clear();
             }
         }
     }
@@ -139,14 +139,14 @@ class SegmentInfo {
     /**
      * Check if a given variable is outdated on the current segments.
      * @param {PathSegment[]} segments The current segments.
-     * @param {string} variableName The variable name to check.
+     * @param {Variable} variable The variable to check.
      * @returns {boolean} `true` if the variable is outdated on the segments.
      */
-    isOutdated(segments, variableName) {
+    isOutdated(segments, variable) {
         for (const segment of segments) {
             const info = this.info.get(segment);
 
-            if (info && info.outdatedReadVariableNames.has(variableName)) {
+            if (info && info.outdatedReadVariables.has(variable)) {
                 return true;
             }
         }
@@ -214,26 +214,22 @@ module.exports = {
                 if (!reference) {
                     return;
                 }
-                const name = reference.identifier.name;
                 const variable = reference.resolved;
                 const writeExpr = getWriteExpr(reference);
                 const isMemberAccess = reference.identifier.parent.type === "MemberExpression";
 
                 // Add a fresh read variable.
                 if (reference.isRead() && !(writeExpr && writeExpr.parent.operator === "=")) {
-                    segmentInfo.markAsRead(codePath.currentSegments, name);
+                    segmentInfo.markAsRead(codePath.currentSegments, variable);
                 }
 
-                const isVariableDeclaration = isLocalVariableWithoutEscape(variable, isMemberAccess) ||
-                    node.parent.type === "VariableDeclarator";
-
                 /*
                  * Register the variable to verify after ESLint traversed the `writeExpr` node
                  * if this reference is an assignment to a variable which is referred from other closure.
                  */
                 if (writeExpr &&
-                    writeExpr.parent.right === writeExpr &&
-                    !isVariableDeclaration
+                    writeExpr.parent.right === writeExpr && // ← exclude variable declarations.
+                    !isLocalVariableWithoutEscape(variable, isMemberAccess)
                 ) {
                     let refs = assignmentReferences.get(writeExpr);
 
@@ -248,7 +244,7 @@ module.exports = {
 
             /*
              * Verify assignments.
-             * If the reference exists in `outdatedReadVariableNames` list, report it.
+             * If the reference exists in `outdatedReadVariables` list, report it.
              */
             ":expression:exit"(node) {
                 const { codePath, referenceMap } = stack;
@@ -270,9 +266,9 @@ module.exports = {
                     assignmentReferences.delete(node);
 
                     for (const reference of references) {
-                        const name = reference.identifier.name;
+                        const variable = reference.resolved;
 
-                        if (segmentInfo.isOutdated(codePath.currentSegments, name)) {
+                        if (segmentInfo.isOutdated(codePath.currentSegments, variable)) {
                             context.report({
                                 node: node.parent,
                                 messageId: "nonAtomicUpdate",
diff --git a/tests/lib/rules/require-atomic-updates.js b/tests/lib/rules/require-atomic-updates.js
index 4fd6bc268935..fbfd3ec483eb 100644
--- a/tests/lib/rules/require-atomic-updates.js
+++ b/tests/lib/rules/require-atomic-updates.js
@@ -186,6 +186,21 @@ ruleTester.run("require-atomic-updates", rule, {
                 const prop = props.find(a => a.id === entry2.id) || null;
               }
             }
+        `,
+
+        `
+            async function run() {
+              {
+                let entry;
+                await entry;
+              }
+              {
+                let entry;
+                () => entry;
+
+                entry = 1;
+              }
+            }
         `
     ],