[New] jsx-boolean-value: add inverse option for always/never

Fixes #1249

Author: ljharb

docs/rules/jsx-boolean-value.md

@@ -6,27 +6,29 @@
 
 ## Rule Details
 
-This rule takes one argument. If it is `"always"` then it warns whenever an attribute is missing its value. If `"never"` then it warns if an attribute has a `true` value. The default value of this option is `"never"`.
+This rule takes two arguments. If the first argument is `"always"` then it warns whenever an attribute is missing its value. If `"never"` then it warns if an attribute has a `true` value. The default value of this option is `"never"`.
 
-The following patterns are considered warnings when configured `"never"`:
+The second argument is optional: if provided, it must be an object with a `"never"` property (if the first argument is `"always"`), or an `"always"` property (if the first argument is `"never"`). This property’s value must be an array of strings representing prop names.
+
+The following patterns are considered warnings when configured `"never"`, or with `"always", { "never": ["personal"] }`:
 
 ```jsx
 var Hello = <Hello personal={true} />;
 ```
 
-The following patterns are not considered warnings when configured `"never"`:
+The following patterns are not considered warnings when configured `"never"`, or with `"always", { "never": ["personal"] }`:
 
 ```jsx
 var Hello = <Hello personal />;
 ```
 
-The following patterns are considered warnings when configured `"always"`:
+The following patterns are considered warnings when configured `"always"`, or with `"never", { "always": ["personal"] }`:
 
 ```jsx
 var Hello = <Hello personal />;
 ```
 
-The following patterns are not considered warnings when configured `"always"`:
+The following patterns are not considered warnings when configured `"always"`, or with `"never", { "always": ["personal"] }`:
 
 ```jsx
 var Hello = <Hello personal={true} />;

lib/rules/jsx-boolean-value.js

@@ -8,6 +8,15 @@
 // Rule Definition
 // ------------------------------------------------------------------------------
 
+const exceptionsSchema = {
+  type: 'array',
+  items: {type: 'string', minLength: 1},
+  uniqueItems: true
+};
+
+const ALWAYS = 'always';
+const NEVER = 'never';
+
 module.exports = {
   meta: {
     docs: {
@@ -17,45 +26,79 @@ module.exports = {
     },
     fixable: 'code',
 
-    schema: [{
-      enum: ['always', 'never']
-    }]
+    schema: {
+      anyOf: [{
+        type: 'array',
+        items: [{enum: [ALWAYS, NEVER]}],
+        additionalItems: false
+      }, {
+        type: 'array',
+        items: [{
+          enum: [ALWAYS]
+        }, {
+          type: 'object',
+          additionalProperties: false,
+          properties: {
+            [NEVER]: exceptionsSchema
+          }
+        }],
+        additionalItems: false
+      }, {
+        type: 'array',
+        items: [{
+          enum: [NEVER]
+        }, {
+          type: 'object',
+          additionalProperties: false,
+          properties: {
+            [ALWAYS]: exceptionsSchema
+          }
+        }],
+        additionalItems: false
+      }]
+    }
   },
 
   create: function(context) {
 
-    var configuration = context.options[0] || 'never';
+    const configuration = context.options[0] || NEVER;
+    const configObject = context.options[1] || {};
+    const exceptions = new Set((configuration === ALWAYS ? configObject[NEVER] : configObject[ALWAYS]) || []);
+    const exceptionProps = Array.from(exceptions, (name) => `\`${name}\``).join(', ');
+    const exceptionsMessage = exceptions.size > 0 ? ` for the following props: ${exceptionProps}` : '';
+    const data = {exceptionsMessage: exceptionsMessage};
 
-    var NEVER_MESSAGE = 'Value must be omitted for boolean attributes';
-    var ALWAYS_MESSAGE = 'Value must be set for boolean attributes';
+    const NEVER_MESSAGE = 'Value must be omitted for boolean attributes{{exceptionsMessage}}';
+    const ALWAYS_MESSAGE = 'Value must be set for boolean attributes{{exceptionsMessage}}';
 
     return {
-      JSXAttribute: function(node) {
-        switch (configuration) {
-          case 'always':
-            if (node.value === null) {
-              context.report({
-                node: node,
-                message: ALWAYS_MESSAGE,
-                fix: function(fixer) {
-                  return fixer.insertTextAfter(node, '={true}');
-                }
-              });
+      JSXAttribute(node) {
+        const propName = node.name && node.name.name;
+        const value = node.value;
+        const isException = exceptions.has(propName);
+
+        const isAlways = configuration === ALWAYS ? !isException : isException;
+        const isNever = configuration === NEVER ? !isException : isException;
+
+        if (isAlways && value === null) {
+          context.report({
+            node: node,
+            message: ALWAYS_MESSAGE,
+            data: data,
+            fix(fixer) {
+              return fixer.insertTextAfter(node, '={true}');
             }
-            break;
-          case 'never':
-            if (node.value && node.value.type === 'JSXExpressionContainer' && node.value.expression.value === true) {
-              context.report({
-                node: node,
-                message: NEVER_MESSAGE,
-                fix: function(fixer) {
-                  return fixer.removeRange([node.name.range[1], node.value.range[1]]);
-                }
-              });
+          });
+        }
+        if (isNever && value && value.type === 'JSXExpressionContainer' && value.expression.value === true) {
+          context.report({
+            node: node,
+            message: NEVER_MESSAGE,
+            data: data,
+            fix(fixer) {
+              return fixer.removeRange([node.name.range[1], value.range[1]]);
             }
-            break;
-          default:
-            break;
+          });
         }
       }
     };

tests/lib/rules/jsx-boolean-value.js

@@ -28,12 +28,17 @@ var ruleTester = new RuleTester({parserOptions});
 ruleTester.run('jsx-boolean-value', rule, {
   valid: [
     {code: '<App foo />;', options: ['never']},
+    {code: '<App foo />;', options: ['always', {never: ['foo']}]},
     {code: '<App foo />;'},
-    {code: '<App foo={true} />;', options: ['always']}
+    {code: '<App foo={true} />;', options: ['always']},
+    {code: '<App foo={true} />;', options: ['never', {always: ['foo']}]}
   ],
   invalid: [{
     code: '<App foo={true} />;', output: '<App foo />;', options: ['never'],
     errors: [{message: 'Value must be omitted for boolean attributes'}]
+  }, {
+    code: '<App foo={true} />;', output: '<App foo />;', options: ['always', {never: ['foo', 'bar']}],
+    errors: [{message: 'Value must be omitted for boolean attributes for the following props: `foo`, `bar`'}]
   }, {
     code: '<App foo={true} />;', output: '<App foo />;',
     errors: [{message: 'Value must be omitted for boolean attributes'}]
@@ -43,5 +48,8 @@ ruleTester.run('jsx-boolean-value', rule, {
   }, {
     code: '<App foo />;', output: '<App foo={true} />;', options: ['always'],
     errors: [{message: 'Value must be set for boolean attributes'}]
+  }, {
+    code: '<App foo />;', output: '<App foo={true} />;', options: ['never', {always: ['foo', 'bar']}],
+    errors: [{message: 'Value must be set for boolean attributes for the following props: `foo`, `bar`'}]
   }]
 });