Add redundantViewBuilder rule (#353)

Co-authored-by: Cal Stephens <[email protected]>

Author: miguel-jimenez-0529

Package.swift

@@ -47,8 +47,8 @@ let package = Package(
 
     .binaryTarget(
       name: "swiftformat",
-      url: "https://github.com/calda/SwiftFormat-nightly/releases/download/2025-12-10-b/SwiftFormat.artifactbundle.zip",
-      checksum: "9f00a9adb66794f253b58f68b4f1687c58804b056ed93e8570a63aff953f98f6"
+      url: "https://github.com/calda/SwiftFormat-nightly/releases/download/2025-12-20/SwiftFormat.artifactbundle.zip",
+      checksum: "0902054e8904dbe233dbcd3c43e5bc0a644cceff1fa599ce950d1295cd146fc0"
     ),
 
     .binaryTarget(

README.md

@@ -4903,6 +4903,62 @@ _You can enable the following settings in Xcode by running [this script](resourc
 
   </details>
 
+- <a id='redundant-viewbuilder'></a>(<a href='#redundant-viewbuilder'>link</a>) **Omit `@ViewBuilder` when it is not required.** `@ViewBuilder` is implicit on `View.body` properties and `ViewModifier.body(content:)` functions, and is unnecessary on single-expression properties or functions.
+
+  <details>
+
+  [![SwiftFormat: redundantViewBuilder](https://img.shields.io/badge/SwiftFormat-redundantViewBuilder-7B0051.svg)](https://github.com/nicklockwood/SwiftFormat/blob/main/Rules.md#redundantViewBuilder)
+
+  #### Why?
+
+  `@ViewBuilder` is automatically applied by the compiler to `View.body` and `ViewModifier.body(content:)`, so adding it explicitly is redundant. Similarly, single-expression properties and functions don't need `@ViewBuilder` since there's only one view being returned.
+
+  ```swift
+  // WRONG
+  struct PlanetView: View {
+    @ViewBuilder
+    var body: some View {
+      Text("Hello, World!")
+    }
+
+    @ViewBuilder
+    var subtitle: some View {
+      Text("Subtitle")
+    }
+  }
+
+  // RIGHT
+  struct PlanetView: View {
+    var body: some View {
+      Text("Hello, World!")
+    }
+
+    var subtitle: some View {
+      Text("Subtitle")
+    }
+  }
+
+  // ALSO RIGHT: @ViewBuilder is necessary for conditionals
+  struct ConditionalView: View {
+    var showDetails: Bool
+
+    var body: some View {
+      title
+    }
+
+    @ViewBuilder
+    var title: some View {
+      if showDetails {
+        Text("Details")
+      } else {
+        Text("Summary")
+      }
+    }
+  }
+  ```
+
+  </details>
+
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 ## Testing

Sources/AirbnbSwiftFormatTool/airbnb.swiftformat

@@ -146,3 +146,4 @@
 --rules redundantTypedThrows
 --rules preferFinalClasses
 --rules simplifyGenericConstraints
+--rules redundantViewBuilder