From 88ef086e39cd055a1cdc6720981f50e4791fb90f Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Mon, 30 Sep 2019 21:09:47 -0700
Subject: tools: update ESLint to v6.5.1

PR-URL: https://github.com/nodejs/node/pull/29785
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: David Carlier <devnexen@gmail.com>
---
 tools/node_modules/eslint/lib/rules/use-isnan.js | 73 ++++++++++++++++++++++--
 1 file changed, 67 insertions(+), 6 deletions(-)

(limited to 'tools/node_modules/eslint/lib/rules/use-isnan.js')

diff --git a/tools/node_modules/eslint/lib/rules/use-isnan.js b/tools/node_modules/eslint/lib/rules/use-isnan.js
index 877c02754a..b2eb84b7b3 100644
--- a/tools/node_modules/eslint/lib/rules/use-isnan.js
+++ b/tools/node_modules/eslint/lib/rules/use-isnan.js
@@ -5,6 +5,19 @@
 
 "use strict";
 
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Determines if the given node is a NaN `Identifier` node.
+ * @param {ASTNode|null} node The node to check.
+ * @returns {boolean} `true` if the node is 'NaN' identifier.
+ */
+function isNaNIdentifier(node) {
+    return Boolean(node) && node.type === "Identifier" && node.name === "NaN";
+}
+
 //------------------------------------------------------------------------------
 // Rule Definition
 //------------------------------------------------------------------------------
@@ -20,21 +33,69 @@ module.exports = {
             url: "https://eslint.org/docs/rules/use-isnan"
         },
 
-        schema: [],
+        schema: [
+            {
+                type: "object",
+                properties: {
+                    enforceForSwitchCase: {
+                        type: "boolean",
+                        default: false
+                    }
+                },
+                additionalProperties: false
+            }
+        ],
+
         messages: {
-            useIsNaN: "Use the isNaN function to compare with NaN."
+            comparisonWithNaN: "Use the isNaN function to compare with NaN.",
+            switchNaN: "'switch(NaN)' can never match a case clause. Use Number.isNaN instead of the switch.",
+            caseNaN: "'case NaN' can never match. Use Number.isNaN before the switch."
         }
     },
 
     create(context) {
 
-        return {
-            BinaryExpression(node) {
-                if (/^(?:[<>]|[!=]=)=?$/u.test(node.operator) && (node.left.name === "NaN" || node.right.name === "NaN")) {
-                    context.report({ node, messageId: "useIsNaN" });
+        const enforceForSwitchCase = context.options[0] && context.options[0].enforceForSwitchCase;
+
+        /**
+         * Checks the given `BinaryExpression` node.
+         * @param {ASTNode} node The node to check.
+         * @returns {void}
+         */
+        function checkBinaryExpression(node) {
+            if (
+                /^(?:[<>]|[!=]=)=?$/u.test(node.operator) &&
+                (isNaNIdentifier(node.left) || isNaNIdentifier(node.right))
+            ) {
+                context.report({ node, messageId: "comparisonWithNaN" });
+            }
+        }
+
+        /**
+         * Checks the discriminant and all case clauses of the given `SwitchStatement` node.
+         * @param {ASTNode} node The node to check.
+         * @returns {void}
+         */
+        function checkSwitchStatement(node) {
+            if (isNaNIdentifier(node.discriminant)) {
+                context.report({ node, messageId: "switchNaN" });
+            }
+
+            for (const switchCase of node.cases) {
+                if (isNaNIdentifier(switchCase.test)) {
+                    context.report({ node: switchCase, messageId: "caseNaN" });
                 }
             }
+        }
+
+        const listeners = {
+            BinaryExpression: checkBinaryExpression
         };
 
+        if (enforceForSwitchCase) {
+            listeners.SwitchStatement = checkSwitchStatement;
+        }
+
+        return listeners;
     }
 };
-- 
cgit v1.2.3