[Fix] jsx-handler-names: false positive when handler name begins with number

Fixes #1686.

Author: jsphstls

lib/rules/jsx-handler-names.js

@@ -92,7 +92,7 @@ module.exports = {
 
     const EVENT_HANDLER_REGEX = !eventHandlerPrefix
       ? null
-      : new RegExp(`^((props\\.${eventHandlerPropPrefix || ''})|((.*\\.)?${eventHandlerPrefix}))[A-Z].*$`);
+      : new RegExp(`^((props\\.${eventHandlerPropPrefix || ''})|((.*\\.)?${eventHandlerPrefix}))[0-9]*[A-Z].*$`);
     const PROP_EVENT_HANDLER_REGEX = !eventHandlerPropPrefix
       ? null
       : new RegExp(`^(${eventHandlerPropPrefix}[A-Z].*|ref)$`);
@@ -138,7 +138,7 @@ module.exports = {
         ) {
           context.report({
             node,
-            message: `Handler function for ${propKey} prop key must begin with '${eventHandlerPrefix}'`
+            message: `Handler function for ${propKey} prop key must be a camelCase name beginning with '${eventHandlerPrefix}' only`
           });
         } else if (
           propFnIsNamedCorrectly

tests/lib/rules/jsx-handler-names.js

@@ -30,6 +30,9 @@ const ruleTester = new RuleTester({parserOptions});
 ruleTester.run('jsx-handler-names', rule, {
   valid: [{
     code: '<TestComponent onChange={this.handleChange} />'
+  }, {
+    // TODO: make this an invalid test
+    code: '<TestComponent onChange={this.handle123Change} />'
   }, {
     code: '<TestComponent onChange={this.props.onChange} />'
   },
@@ -148,19 +151,31 @@ ruleTester.run('jsx-handler-names', rule, {
 
   invalid: [{
     code: '<TestComponent onChange={this.doSomethingOnChange} />',
-    errors: [{message: 'Handler function for onChange prop key must begin with \'handle\''}]
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}]
   }, {
     code: '<TestComponent onChange={this.handlerChange} />',
-    errors: [{message: 'Handler function for onChange prop key must begin with \'handle\''}]
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}]
+  }, {
+    code: '<TestComponent onChange={this.handle} />',
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}]
+  }, {
+    code: '<TestComponent onChange={this.handle2} />',
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}]
+  }, {
+    code: '<TestComponent onChange={this.handl3Change} />',
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}]
+  }, {
+    code: '<TestComponent onChange={this.handle4change} />',
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}]
   }, {
     code: '<TestComponent onChange={takeCareOfChange} />',
-    errors: [{message: 'Handler function for onChange prop key must begin with \'handle\''}],
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}],
     options: [{
       checkLocalVariables: true
     }]
   }, {
     code: '<TestComponent onChange={() => this.takeCareOfChange()} />',
-    errors: [{message: 'Handler function for onChange prop key must begin with \'handle\''}],
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}],
     options: [{
       checkInlineFunction: true
     }]
@@ -202,14 +217,14 @@ ruleTester.run('jsx-handler-names', rule, {
     }]
   }, {
     code: '<TestComponent onChange={this.onChange} />',
-    errors: [{message: 'Handler function for onChange prop key must begin with \'handle\''}]
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}]
   }, {
     code: '<TestComponent onChange={props::onChange} />',
     parser: parsers.BABEL_ESLINT,
-    errors: [{message: 'Handler function for onChange prop key must begin with \'handle\''}]
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}]
   }, {
     code: '<TestComponent onChange={props.foo::onChange} />',
     parser: parsers.BABEL_ESLINT,
-    errors: [{message: 'Handler function for onChange prop key must begin with \'handle\''}]
+    errors: [{message: 'Handler function for onChange prop key must be a camelCase name beginning with \'handle\' only'}]
   }]
 });