prefer_asserts_with_message

Prefer asserts with message.

When assertions fail it's not always simple to understand why. Adding a message to the assert helps the developer to understand why the AssertionError occurs.

BAD:

f(a) {  assert(a != null); } ​ class A {  A(a) : assert(a != null); } 

GOOD:

f(a) {  assert(a != null, 'a must not be null'); } ​ class A {  A(a) : assert(a != null, 'a must not be null'); } 

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

linter:  rules:  - prefer_asserts_with_message 

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

linter:  rules:  prefer_asserts_with_message: true