From 12f256f22534c4a4e1ca0ba54c37c6db81441461 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=96=9B=E5=AE=9A=E8=B0=94=E7=9A=84=E7=8C=AB?=
 <weiran.zsd@outlook.com>
Date: Fri, 5 Apr 2019 04:33:54 +0800
Subject: [PATCH] Breaking: no-confusing-arrow enable allowParens: true (fixes
 #11503) (#11520)

---
 docs/rules/no-confusing-arrow.md      |  2 +-
 lib/rules/no-confusing-arrow.js       |  8 ++++---
 tests/lib/rules/no-confusing-arrow.js | 30 +++++++++++++++++----------
 3 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/docs/rules/no-confusing-arrow.md b/docs/rules/no-confusing-arrow.md
index dca249f798b..6947af0fb86 100644
--- a/docs/rules/no-confusing-arrow.md
+++ b/docs/rules/no-confusing-arrow.md
@@ -48,7 +48,7 @@ This rule accepts a single options argument with the following defaults:
 }
 ```
 
-`allowParens` is a boolean setting that can be `true` or `false`:
+`allowParens` is a boolean setting that can be `true`(default) or `false`:
 
 1. `true` relaxes the rule and accepts parenthesis as a valid "confusion-preventing" syntax.
 2. `false` warns even if the expression is wrapped in parenthesis
diff --git a/lib/rules/no-confusing-arrow.js b/lib/rules/no-confusing-arrow.js
index 79df9a51387..09d6e27d216 100644
--- a/lib/rules/no-confusing-arrow.js
+++ b/lib/rules/no-confusing-arrow.js
@@ -41,7 +41,7 @@ module.exports = {
         schema: [{
             type: "object",
             properties: {
-                allowParens: { type: "boolean", default: false }
+                allowParens: { type: "boolean", default: true }
             },
             additionalProperties: false
         }],
@@ -53,8 +53,10 @@ module.exports = {
 
     create(context) {
         const config = context.options[0] || {};
+        const allowParens = config.allowParens || (config.allowParens === void 0);
         const sourceCode = context.getSourceCode();
 
+
         /**
          * Reports if an arrow function contains an ambiguous conditional.
          * @param {ASTNode} node - A node to check and report.
@@ -63,14 +65,14 @@ module.exports = {
         function checkArrowFunc(node) {
             const body = node.body;
 
-            if (isConditional(body) && !(config.allowParens && astUtils.isParenthesised(sourceCode, body))) {
+            if (isConditional(body) && !(allowParens && astUtils.isParenthesised(sourceCode, body))) {
                 context.report({
                     node,
                     messageId: "confusing",
                     fix(fixer) {
 
                         // if `allowParens` is not set to true dont bother wrapping in parens
-                        return config.allowParens && fixer.replaceText(node.body, `(${sourceCode.getText(node.body)})`);
+                        return allowParens && fixer.replaceText(node.body, `(${sourceCode.getText(node.body)})`);
                     }
                 });
             }
diff --git a/tests/lib/rules/no-confusing-arrow.js b/tests/lib/rules/no-confusing-arrow.js
index 7df2538a2d0..8c7efe6e287 100644
--- a/tests/lib/rules/no-confusing-arrow.js
+++ b/tests/lib/rules/no-confusing-arrow.js
@@ -21,47 +21,55 @@ const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 6 } });
 ruleTester.run("no-confusing-arrow", rule, {
     valid: [
         "a => { return 1 ? 2 : 3; }",
+        { code: "a => { return 1 ? 2 : 3; }", options: [{ allowParens: false }] },
+
         "var x = a => { return 1 ? 2 : 3; }",
+        { code: "var x = a => { return 1 ? 2 : 3; }", options: [{ allowParens: false }] },
+
         "var x = (a) => { return 1 ? 2 : 3; }",
+        { code: "var x = (a) => { return 1 ? 2 : 3; }", options: [{ allowParens: false }] },
+
+        "var x = a => (1 ? 2 : 3)",
         { code: "var x = a => (1 ? 2 : 3)", options: [{ allowParens: true }] }
     ],
     invalid: [
         {
             code: "a => 1 ? 2 : 3",
-            output: null,
+            output: "a => (1 ? 2 : 3)",
             errors: [{ messageId: "confusing" }]
         },
         {
-            code: "var x = a => 1 ? 2 : 3",
-            output: null,
+            code: "a => 1 ? 2 : 3",
+            output: "a => (1 ? 2 : 3)",
+            options: [{ allowParens: true }],
             errors: [{ messageId: "confusing" }]
         },
         {
-            code: "var x = (a) => 1 ? 2 : 3",
+            code: "a => 1 ? 2 : 3",
             output: null,
+            options: [{ allowParens: false }],
             errors: [{ messageId: "confusing" }]
         },
         {
-            code: "var x = a => (1 ? 2 : 3)",
-            output: null,
+            code: "var x = a => 1 ? 2 : 3",
+            output: "var x = a => (1 ? 2 : 3)",
             errors: [{ messageId: "confusing" }]
         },
         {
-            code: "a => 1 ? 2 : 3",
-            output: "a => (1 ? 2 : 3)",
+            code: "var x = a => 1 ? 2 : 3",
+            output: "var x = a => (1 ? 2 : 3)",
             options: [{ allowParens: true }],
             errors: [{ messageId: "confusing" }]
         },
         {
             code: "var x = a => 1 ? 2 : 3",
-            output: "var x = a => (1 ? 2 : 3)",
-            options: [{ allowParens: true }],
+            output: null,
+            options: [{ allowParens: false }],
             errors: [{ messageId: "confusing" }]
         },
         {
             code: "var x = (a) => 1 ? 2 : 3",
             output: "var x = (a) => (1 ? 2 : 3)",
-            options: [{ allowParens: true }],
             errors: [{ messageId: "confusing" }]
         }
     ]