add info for observable behavior vs implementation details

sarven · sarven · commit ad23aa1b1cbc · 2021-03-02T20:44:54.000+01:00
diff --git a/README.md b/README.md
@@ -956,6 +956,10 @@ final class ValidTestExample extends TestCase
 }
 ```
 
+:information_source: The first subscription model has a bad design. To invoke one business operation you need to call three methods. Also using getters to verify operation is not a good practice.
+In this case, it's skipped checking a change of modifiedAt, probably setting specific modifiedAt during a renew operation can be tested with an expiration business operation. The getter for modifiedAt is not required.
+Of course, there are cases where finding the possibility to avoid getters provided only for tests will be very hard, but always we should try to not introduce them.
+
 ## Unit of behavior
 
 :x: Bad:

Original file line number	Diff line number	Diff line change
`@@ -956,6 +956,10 @@ final class ValidTestExample extends TestCase`
`956`	`956`	`}`
`957`	`957`	```
`958`	`958`
	`959`	`+:information_source: The first subscription model has a bad design. To invoke one business operation you need to call three methods. Also using getters to verify operation is not a good practice.`
	`960`	`+In this case, it's skipped checking a change of modifiedAt, probably setting specific modifiedAt during a renew operation can be tested with an expiration business operation. The getter for modifiedAt is not required.`
	`961`	`+Of course, there are cases where finding the possibility to avoid getters provided only for tests will be very hard, but always we should try to not introduce them.`
	`962`	`+`
`959`	`963`	`## Unit of behavior`
`960`	`964`
`961`	`965`	`:x: Bad:`