Update: add fixer for dot-notation (fixes #7014)

docs/rules/dot-notation.md

@@ -1,5 +1,7 @@
 # Require Dot Notation (dot-notation)
 
+(fixable) The `--fix` option on the [command line](../user-guide/command-line-interface#fix) automatically fixes problems reported by this rule.
+
 In JavaScript, one can access properties using the dot notation (`foo.bar`) or square-bracket notation (`foo["bar"]`). However, the dot notation is often preferred because it is easier to read, less verbose, and works better with aggressive JavaScript minimizers.
 
 ```js

lib/rules/dot-notation.js

@@ -32,12 +32,15 @@ module.exports = {
                 },
                 additionalProperties: false
             }
-        ]
+        ],
+
+        fixable: "code"
     },
 
     create(context) {
         const options = context.options[0] || {};
         const allowKeywords = options.allowKeywords === void 0 || !!options.allowKeywords;
+        const sourceCode = context.getSourceCode();
 
         let allowPattern;
 
@@ -59,6 +62,23 @@ module.exports = {
                             message: "[{{propertyValue}}] is better written in dot notation.",
                             data: {
                                 propertyValue: JSON.stringify(node.property.value)
+                            },
+                            fix(fixer) {
+                                const leftBracket = sourceCode.getTokenBefore(node.property);
+                                const rightBracket = sourceCode.getTokenAfter(node.property);
+                                const textBeforeProperty = sourceCode.text.slice(leftBracket.range[1], node.property.range[0]);
+                                const textAfterProperty = sourceCode.text.slice(node.property.range[1], rightBracket.range[0]);
+
+                                if (textBeforeProperty.trim() || textAfterProperty.trim()) {
+
+                                    // Don't perform any fixes if there are comments inside the brackets.
+                                    return null;
+                                }
+
+                                return fixer.replaceTextRange(
+                                    [leftBracket.range[0], rightBracket.range[1]],
+                                    `.${node.property.value}`
+                                );
                             }
                         });
                     }
@@ -73,6 +93,21 @@ module.exports = {
                         message: ".{{propertyName}} is a syntax error.",
                         data: {
                             propertyName: node.property.name
+                        },
+                        fix(fixer) {
+                            const dot = sourceCode.getTokenBefore(node.property);
+                            const textAfterDot = sourceCode.text.slice(dot.range[1], node.property.range[0]);
+
+                            if (textAfterDot.trim()) {
+
+                                // Don't perform any fixes if there are comments between the dot and the property name.
+                                return null;
+                            }
+
+                            return fixer.replaceTextRange(
+                                [dot.range[0], node.property.range[1]],
+                                `[${textAfterDot}"${node.property.name}"]`
+                            );
                         }
                     });
                 }

tests/lib/rules/dot-notation.js

@@ -47,13 +47,43 @@ ruleTester.run("dot-notation", rule, {
         "a[b()];"
     ],
     invalid: [
-        { code: "a.true;", options: [{allowKeywords: false}], errors: [{ message: ".true is a syntax error." }] },
-        { code: "a['true'];", errors: [{ message: "[\"true\"] is better written in dot notation." }] },
-        { code: "a[null];", errors: [{ message: "[null] is better written in dot notation." }] },
-        { code: "a['b'];", errors: [{ message: "[\"b\"] is better written in dot notation." }] },
-        { code: "a.b['c'];", errors: [{ message: "[\"c\"] is better written in dot notation." }] },
-        { code: "a['_dangle'];", options: [{allowPattern: "^[a-z]+(_[a-z]+)+$"}], errors: [{ message: "[\"_dangle\"] is better written in dot notation." }] },
-        { code: "a['SHOUT_CASE'];", options: [{allowPattern: "^[a-z]+(_[a-z]+)+$"}], errors: [{ message: "[\"SHOUT_CASE\"] is better written in dot notation." }] },
+        {
+            code: "a.true;",
+            options: [{allowKeywords: false}],
+            errors: [{ message: ".true is a syntax error." }],
+            output: "a[\"true\"];"
+        },
+        {
+            code: "a['true'];",
+            errors: [{ message: "[\"true\"] is better written in dot notation." }],
+            output: "a.true;"
+        },
+        {
+            code: "a[null];",
+            errors: [{ message: "[null] is better written in dot notation." }],
+            output: "a.null;"
+        },
+        {
+            code: "a['b'];",
+            errors: [{ message: "[\"b\"] is better written in dot notation." }],
+            output: "a.b;"
+        },
+        {
+            code: "a.b['c'];",
+            errors: [{ message: "[\"c\"] is better written in dot notation." }],
+            output: "a.b.c;"
+        },
+        {
+            code: "a['_dangle'];",
+            options: [{allowPattern: "^[a-z]+(_[a-z]+)+$"}], errors: [{ message: "[\"_dangle\"] is better written in dot notation." }],
+            output: "a._dangle;"
+        },
+        {
+            code: "a['SHOUT_CASE'];",
+            options: [{allowPattern: "^[a-z]+(_[a-z]+)+$"}],
+            errors: [{ message: "[\"SHOUT_CASE\"] is better written in dot notation." }],
+            output: "a.SHOUT_CASE;"
+        },
         {
             code:
                 "a\n" +
@@ -62,7 +92,10 @@ ruleTester.run("dot-notation", rule, {
                 message: "[\"SHOUT_CASE\"] is better written in dot notation.",
                 line: 2,
                 column: 4
-            }]
+            }],
+            output:
+                "a\n" +
+                "  .SHOUT_CASE;"
         },
         {
             code:
@@ -82,7 +115,44 @@ ruleTester.run("dot-notation", rule, {
                     line: 5,
                     column: 6
                 }
-            ]
+            ],
+            output:
+            "getResource()\n" +
+            "    .then(function(){})\n" +
+            "    .catch(function(){})\n" +
+            "    .then(function(){})\n" +
+            "    .catch(function(){});"
+        },
+        {
+            code:
+            "foo\n" +
+            "  .while;",
+            options: [{ allowKeywords: false }],
+            errors: [{ message: ".while is a syntax error." }],
+            output:
+            "foo\n" +
+            "  [\"while\"];"
+        },
+        {
+            code: "foo[ /* comment */ 'bar' ]",
+            errors: [{ message: "[\"bar\"] is better written in dot notation." }],
+            output: "foo[ /* comment */ 'bar' ]" // Not fixed due to comment
+        },
+        {
+            code: "foo[ 'bar' /* comment */ ]",
+            errors: [{ message: "[\"bar\"] is better written in dot notation." }],
+            output: "foo[ 'bar' /* comment */ ]" // Not fixed due to comment
+        },
+        {
+            code: "foo[    'bar'    ];",
+            errors: [{ message: "[\"bar\"] is better written in dot notation." }],
+            output: "foo.bar;"
+        },
+        {
+            code: "foo. /* comment */ while",
+            options: [{ allowKeywords: false }],
+            errors: [{ message: ".while is a syntax error." }],
+            output: "foo. /* comment */ while" // Not fixed due to comment
         }
     ]
 });