camel_case_extensions

Name extensions using UpperCamelCase.

From Effective Dart:

DO name extensions using UpperCamelCase.

Extensions should capitalize the first letter of each word (including the first word), and use no separators.

GOOD:

extension MyFancyList<T> on List<T> {  // ... } ​ extension SmartIterable<T> on Iterable<T> {  // ... } 

To enable the camel_case_extensions rule, add camel_case_extensions under linter > rules in your analysis_options.yaml file:

linter:  rules:  - camel_case_extensions 

If you're instead using the YAML map syntax to configure linter rules, add camel_case_extensions: true under linter > rules:

linter:  rules:  camel_case_extensions: true