Merge pull request #368 from green-code-initiative/vlj/GCI90

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- GCI90 C#: Use `Cast` instead of `Select` to cast.
+
 ### Added
 
 ### Changed

RULES.md

@@ -66,6 +66,7 @@ Some are applicable for different technologies.
 | GCI87    | Use collection indexer                                        | Collection indexers should be used instead of Linq, when available                                                                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                         | 🚫   | 🚫  | 🚫 | 🚫     | 🚫   | ✅  | 🚫   |
 | GCI88    | Dispose resource asynchronously                               | Resources that implement `IAsyncDisposable` should be disposed asynchronously                                                                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                         | 🚫   | 🚫  | 🚫 | 🚫     | 🚫   | ✅  | 🚫   |
 | GCI89    | Avoid using function cache without limit                      | If a function has decorators without max size cache, the program will store unlimited data                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                         | ❓    | ❓   | ❓  | ✅      | ❓    | ❓  | ❓    |
+| GCI90    | Use `Cast` instead of `Select` to cast                        | `Cast` is optimized for this scenario and should be used                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                         | ❓    | ❓   | ❓  | ❓      | ❓    | ✅  | ❓    |
 | GCI91    | Use `Where` before `OrderBy`                                  | Filter elements before sorting them for improved efficiency                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                         | ❓    | ❓   | ❓  | ❓      | ❓    | ✅  | ❓    |
 | GCI92    | Use string.Length instead of comparison with empty string     | Comparing a string to an empty string is unnecessary and can be replaced by a call to `string.Length` which is more performant and more readable.                                                                                                                                                                                                                                                                             |                                                                                                                                                                         | 🚫   | 🚫  | 🚫 | 🚫     | 🚫   | ✅  | 🚫   |
 | GCI93    | Return `Task` directly                                        | Consider returning a `Task` directly instead of a single `await`                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                         | ❓    | ❓   | ❓  | ❓      | ❓    | ✅  | ❓    |

src/main/rules/GCI90/GCI90.json

@@ -0,0 +1,16 @@
+{
+  "title": "Use Cast instead of Select to cast",
+  "type": "CODE_SMELL",
+  "status": "ready",
+  "remediation": {
+    "func": "Constant\/Issue",
+    "constantCost": "5min"
+  },
+  "tags": [
+    "eco-design",
+    "creedengo",
+    "performance",
+    "bad-practice"
+  ],
+  "defaultSeverity": "Major"
+}

src/main/rules/GCI90/csharp/GCI90.asciidoc

@@ -0,0 +1,31 @@
+:!sectids:
+
+Use Cast instead of Select to cast.
+
+== Why is this an issue ?
+
+Cast is more efficient than Select for casting operations, its usage leads to better performance.
+
+=== When can it be ignored ?
+
+This rule shouldn't be ignored.
+
+== Non compliant example
+
+[source, cs]
+----
+void Test(IEnumerable<string> items)
+{
+    var asObjects = items.Select(x => (object)x);
+}
+----
+
+== Compliant example
+
+[source, cs]
+----
+void Test(IEnumerable<string> items)
+{
+    var asObjects = items.Cast<object>();
+}
+----

src/main/rules/GCI91/GCI91.json

@@ -13,4 +13,4 @@
     "bad-practice"
   ],
   "defaultSeverity": "Major"
-}
+}