Modify Rule S1155: Improve description for Dart

rules/S1155/dart/rule.adoc

@@ -2,6 +2,26 @@
 
 When you call `isEmpty` or `isNotEmpty`, it clearly communicates the code's intention, which is to check if the collection is empty. Using `.length == 0` for this purpose is less direct and makes the code slightly more complex.
 
+The rule also raises issues if the comparisons don't make sense. For example, `length` is always 0 or higher, so you don't need to write the following conditions:
+
+[source,dart]
+----
+void fun(List<int> myList) {
+  if (myList.length >= 0) { // Noncompliant, the condition is always true
+    // do something
+  }
+
+  if (myList.length < 0) { // Noncompliant, the condition is always false
+    // do something
+  }
+
+}
+----
+
+=== Code examples
+
+==== Noncompliant code example
+
 [source,dart,diff-id=1,diff-type=noncompliant]
 ----
 void fun(List<int> myList) {
@@ -16,6 +36,7 @@ void fun(List<int> myList) {
 }
 ----
 
+==== Compliant solution
 
 [source,dart,diff-id=1,diff-type=compliant]
 ----
@@ -33,4 +54,23 @@ void fun(List<int> myList) {
 
 == Resources
 
-* https://dart.dev/tools/linter-rules/prefer_is_empty[Dart Lint rule]
+* Dart Docs - https://dart.dev/tools/linter-rules/prefer_is_empty[Dart Linter rule]
+
+ifdef::env-github,rspecator-view[]
+
+'''
+== Implementation Specification
+(visible only on this page)
+
+=== Message
+
+* Use 'isEmpty'/'isNotEmpty' instead of 'length' to test whether the collection is 'empty'/'not empty'.
+* The comparison is always 'true'/'false' because the length is always greater than or equal to 0.
+
+=== Highlighting
+
+The condition of the `if` statement.
+
+'''
+
+endif::env-github,rspecator-view[]