Observe input extension

Author: wickwirew

Package.swift

@@ -19,7 +19,7 @@ let package = Package(
         .executable(name: "OtterCLI", targets: ["OtterCLI"]),
     ],
     dependencies: [
-        .package(url: "https://github.com/apple/swift-syntax.git", from: "601.0.1"),
+        .package(url: "https://github.com/apple/swift-syntax", from: "601.0.1"),
         .package(url: "https://github.com/apple/swift-collections", from: "1.1.4"),
         .package(url: "https://github.com/apple/swift-argument-parser", from: "1.5.0"),
     ],

Sources/Compiler/Gen/SwiftLanguage.swift

@@ -545,30 +545,47 @@ public struct SwiftLanguage: Language {
         for query: GeneratedQuery,
         input: GeneratedModel
     ) {
-        extensionOn("Query") {
-            self.writer.write("Input == ", query.inputName)
-        } builder: {
-            writer.write("func execute(")
+        let writeInput: () -> Void = {
             for (position, field) in input.fields.elements.positional() {
                 writer.write(field.value.name, ": ", field.value.type.description)
 
                 if !position.isLast {
                     writer.write(", ")
                 }
             }
-            
+        }
+        
+        let initInput: () -> Void = {
+            for (position, field) in input.fields.elements.positional() {
+                writer.write(field.key, ": ", field.key)
+                
+                if !position.isLast {
+                    writer.write(", ")
+                }
+            }
+        }
+        
+        extensionOn("Query") {
+            self.writer.write("Input == ", query.inputName)
+        } builder: {
+            writer.write("func execute(")
+            writeInput()
             writer.write(") async throws -> Output ")
+            
             writer.braces {
                 writer.write(line: "try await execute(with: ", query.inputName, "(")
-                
-                for (position, field) in input.fields.elements.positional() {
-                    writer.write(field.key, ": ", field.key)
-                    
-                    if !position.isLast {
-                        writer.write(", ")
-                    }
-                }
-                
+                initInput()
+                writer.write("))")
+            }
+            
+            writer.blankLine()
+            writer.write(line: "func observe(")
+            writeInput()
+            writer.write(") -> any QueryObservation<Output> ")
+            
+            writer.braces {
+                writer.write(line: "observe(with: ", query.inputName, "(")
+                initInput()
                 writer.write("))")
             }
         }
@@ -595,6 +612,7 @@ public struct SwiftLanguage: Language {
         }
 
         writer.braces {
+            writer.blankLine()
             builder()
         }
         writer.blankLine()

Tests/CompilerTests/Gen/Swift.output

@@ -356,9 +356,14 @@ typealias SelectUserByIdQuery = Query<Int, User?>
 typealias SelectUserByIdsQuery = Query<[Int], [User]>
 typealias SelectUserByNameQuery = Query<String, [User]>
 typealias SelectUserWithManyInputsQuery = Query<SelectUserWithManyInputsInput, SelectUserWithManyInputsOutput?>
-extension Query where Input == SelectUserWithManyInputsInput {func execute(id: Int, firstName: String) async throws -> Output {
+extension Query where Input == SelectUserWithManyInputsInput {
+    func execute(id: Int, firstName: String) async throws -> Output {
         try await execute(with: SelectUserWithManyInputsInput(id: id, firstName: firstName))
     }
+    
+    func observe(id: Int, firstName: String) -> any QueryObservation<Output> {
+        observe(with: SelectUserWithManyInputsInput(id: id, firstName: firstName))
+    }
 }
 
 typealias SelectWithInterestQuery = Query<(), [SelectWithInterestOutput]>