From 19ab6666e8e4142a183bdee2be96e5bafbac0e21 Mon Sep 17 00:00:00 2001
From: Milos Djermanovic <milos.djermanovic@gmail.com>
Date: Sun, 18 Aug 2019 07:52:59 +0200
Subject: [PATCH] Fix: yoda exceptRange false positives on empty string
 property names (#12071)

---
 lib/rules/yoda.js       |  2 +-
 tests/lib/rules/yoda.js | 68 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/lib/rules/yoda.js b/lib/rules/yoda.js
index 43783c193bd..89c4a8afd11 100644
--- a/lib/rules/yoda.js
+++ b/lib/rules/yoda.js
@@ -119,7 +119,7 @@ function same(a, b) {
             const nameA = astUtils.getStaticPropertyName(a);
 
             // x.y = x["y"]
-            if (nameA) {
+            if (nameA !== null) {
                 return (
                     same(a.object, b.object) &&
                     nameA === astUtils.getStaticPropertyName(b)
diff --git a/tests/lib/rules/yoda.js b/tests/lib/rules/yoda.js
index 89979ff58b0..d2c18347740 100644
--- a/tests/lib/rules/yoda.js
+++ b/tests/lib/rules/yoda.js
@@ -50,6 +50,14 @@ ruleTester.run("yoda", rule, {
         }, {
             code: "if ('blue' < x.y && x.y < 'green') {}",
             options: ["never", { exceptRange: true }]
+        }, {
+            code: "if (0 < x[``] && x[``] < 100) {}",
+            options: ["never", { exceptRange: true }],
+            parserOptions: { ecmaVersion: 2015 }
+        }, {
+            code: "if (0 < x[''] && x[``] < 100) {}",
+            options: ["never", { exceptRange: true }],
+            parserOptions: { ecmaVersion: 2015 }
         }, {
             code: "if (0 <= x['y'] && x['y'] <= 100) {}",
             options: ["never", { exceptRange: true }]
@@ -332,6 +340,66 @@ ruleTester.run("yoda", rule, {
                 }
             ]
         },
+        {
+            code: "if (0 <= a[''] && a.b < 1) {}",
+            output: "if (a[''] >= 0 && a.b < 1) {}",
+            options: ["never", { exceptRange: true }],
+            errors: [
+                {
+                    messageId: "expected",
+                    data: { expectedSide: "right", operator: "<=" },
+                    type: "BinaryExpression"
+                }
+            ]
+        },
+        {
+            code: "if (0 <= a[''] && a[' '] < 1) {}",
+            output: "if (a[''] >= 0 && a[' '] < 1) {}",
+            options: ["never", { exceptRange: true }],
+            errors: [
+                {
+                    messageId: "expected",
+                    data: { expectedSide: "right", operator: "<=" },
+                    type: "BinaryExpression"
+                }
+            ]
+        },
+        {
+            code: "if (0 <= a[''] && a[null] < 1) {}",
+            output: "if (a[''] >= 0 && a[null] < 1) {}",
+            options: ["never", { exceptRange: true }],
+            errors: [
+                {
+                    messageId: "expected",
+                    data: { expectedSide: "right", operator: "<=" },
+                    type: "BinaryExpression"
+                }
+            ]
+        },
+        {
+            code: "if (0 <= a[''] && a[b] < 1) {}",
+            output: "if (a[''] >= 0 && a[b] < 1) {}",
+            options: ["never", { exceptRange: true }],
+            errors: [
+                {
+                    messageId: "expected",
+                    data: { expectedSide: "right", operator: "<=" },
+                    type: "BinaryExpression"
+                }
+            ]
+        },
+        {
+            code: "if (0 <= a[''] && a[b()] < 1) {}",
+            output: "if (a[''] >= 0 && a[b()] < 1) {}",
+            options: ["never", { exceptRange: true }],
+            errors: [
+                {
+                    messageId: "expected",
+                    data: { expectedSide: "right", operator: "<=" },
+                    type: "BinaryExpression"
+                }
+            ]
+        },
         {
             code: "if (0 <= a[b()] && a[b()] < 1) {}",
             output: "if (a[b()] >= 0 && a[b()] < 1) {}",