feat: add NullEncodable property wrapper

Author: grdsdev

Sources/PostgREST/NullEncodable.swift

@@ -0,0 +1,42 @@
+//
+//  NullEncodable.swift
+//
+//
+//  Created by Guilherme Souza on 19/12/23.
+//
+
+import Foundation
+
+@propertyWrapper
+public struct NullEncodable<T>: Encodable where T: Encodable {
+  public var wrappedValue: T?
+
+  public init(wrappedValue: T? = nil) {
+    self.wrappedValue = wrappedValue
+  }
+
+  public func encode(to encoder: Encoder) throws {
+    var container = encoder.singleValueContainer()
+
+    if let wrappedValue {
+      try container.encode(wrappedValue)
+    } else {
+      try container.encodeNil()
+    }
+  }
+}
+
+extension NullEncodable: Equatable where T: Equatable {}
+extension NullEncodable: Hashable where T: Hashable {}
+
+extension NullEncodable: Decodable where T: Decodable {
+  public init(from decoder: Decoder) throws {
+    let container = try decoder.singleValueContainer()
+
+    if container.decodeNil() {
+      self.init(wrappedValue: nil)
+    } else {
+      try self.init(wrappedValue: container.decode(T.self))
+    }
+  }
+}

Sources/PostgREST/PostgrestQueryBuilder.swift

@@ -69,15 +69,6 @@ public final class PostgrestQueryBuilder: PostgrestBuilder {
       if !prefersHeaders.isEmpty {
         $0.request.headers["Prefer"] = prefersHeaders.joined(separator: ",")
       }
-
-      // TODO: How to do this in Swift?
-      // if (Array.isArray(values)) {
-      //     const columns = values.reduce((acc, x) => acc.concat(Object.keys(x)), [] as string[])
-      //     if (columns.length > 0) {
-      //         const uniqueColumns = [...new Set(columns)].map((column) => `"${column}"`)
-      //         this.url.searchParams.set('columns', uniqueColumns.join(','))
-      //     }
-      // }
     }
 
     return PostgrestFilterBuilder(self)

Tests/PostgRESTTests/BuildURLRequestTests.swift

@@ -110,7 +110,7 @@ final class BuildURLRequestTests: XCTestCase {
         await client.schema("storage")
           .from("objects")
           .select()
-      }
+      },
     ]
 
     for testCase in testCases {

Tests/PostgRESTTests/NullEncodableTests.swift

@@ -0,0 +1,49 @@
+//
+//  NullEncodableTests.swift
+//
+//
+//  Created by Guilherme Souza on 19/12/23.
+//
+
+import PostgREST
+import XCTest
+
+final class NullEncodableTests: XCTestCase {
+  struct Item: Encodable {
+    var email: String
+    @NullEncodable var username: String?
+  }
+
+  func testEncode() throws {
+    let items = [
+      Item(email: "[email protected]", username: .init(wrappedValue: "example")),
+      Item(email: "[email protected]", username: .init(wrappedValue: nil)),
+      Item(email: "[email protected]", username: .init(wrappedValue: "example3")),
+    ]
+
+    let encoder = JSONEncoder()
+    encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
+    let data = try encoder.encode(items)
+    let jsonString = try XCTUnwrap(String(data: data, encoding: .utf8))
+
+    XCTAssertEqual(
+      jsonString,
+      """
+      [
+        {
+          "email" : "[email protected]",
+          "username" : "example"
+        },
+        {
+          "email" : "[email protected]",
+          "username" : null
+        },
+        {
+          "email" : "[email protected]",
+          "username" : "example3"
+        }
+      ]
+      """
+    )
+  }
+}