Create rule S7095: Unnecessary braces in string interpolation should …

…be removed (unnecessary_brace_in_string_interps) (#4325)

Co-authored-by: antonioaversa <[email protected]>

rules/S7095/dart/metadata.json

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+{
+  "title": "Unnecessary braces in string interpolation should be removed",
+  "type": "CODE_SMELL",
+  "status": "ready",
+  "remediation": {
+    "func": "Constant\/Issue",
+    "constantCost": "1min"
+  },
+  "tags": [
+  ],
+  "defaultSeverity": "Major",
+  "ruleSpecification": "RSPEC-7095",
+  "sqKey": "S7095",
+  "scope": "All",
+  "defaultQualityProfiles": ["Sonar way"],
+  "quickfix": "unknown",
+  "code": {
+    "impacts": {
+      "MAINTAINABILITY": "LOW"
+    },
+    "attribute": "FORMATTED"
+  }
+}

rules/S7095/dart/rule.adoc

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+Unnecessary braces in string interpolation should be removed.
+
+== Why is this an issue?
+
+Dart https://dart.dev/language/built-in-types#strings[strings] support interpolation, which allows you to embed expressions within a string.
+
+[source,dart]
+----
+String expression = 'words';
+print('A string containing ${expression}');
+----
+
+When the expression is a simple identifier, and the identifier is followed in the string interpolation by a character which is not allowed in an identifier (e.g. whitespace, `:`, `-` but not a letter, digit, ``++_++``, ...), you can omit the curly braces. 
+
+This makes the code more readable and concise.
+
+[source,dart]
+----
+String expression = 'words';
+print('A string containing $expression');
+----
+
+== How to fix it
+
+Remove the curly braces.
+
+=== Code examples
+
+==== Noncompliant code example
+
+[source,dart,diff-id=1,diff-type=noncompliant]
+----
+String expression = 'words';
+print('A string containing ${expression}');
+----
+
+==== Compliant solution
+
+[source,dart,diff-id=1,diff-type=compliant]
+----
+String expression = 'words';
+print('A string containing $expression');
+----
+
+== Resources
+
+=== Documentation
+
+* Dart Docs - https://dart.dev/tools/linter-rules/unnecessary_brace_in_string_interps[Dart Linter rule - unnecessary_brace_in_string_interps]
+* Dart Docs - https://dart.dev/language/built-in-types#strings[Language - Strings]
+
+ifdef::env-github,rspecator-view[]
+
+'''
+== Implementation Specification
+(visible only on this page)
+
+=== Message
+
+Unnecessary braces in a string interpolation.
+
+=== Highlighting
+
+The interpolation expression, including the ``++$++`` sign and the braces: e.g. ``++${expression}++`` in ``++'A string containing ${expression}'++``.
+
+'''
+== Comments And Links
+(visible only on this page)
+
+endif::env-github,rspecator-view[]

rules/S7095/metadata.json

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+{
+}