add PostgreSQLUpsert support + test

Author: tanner0101

Sources/FluentPostgreSQL/FluentPostgreSQLQuery.swift

@@ -24,6 +24,7 @@ public struct FluentPostgreSQLQuery: FluentSQLQuery {
     public typealias SelectExpression = PostgreSQLSelectExpression
     public typealias Join = PostgreSQLJoin
     public typealias OrderBy = PostgreSQLOrderBy
+    public typealias Upsert = PostgreSQLUpsert
 
     public var statement: Statement
     public var table: TableIdentifier
@@ -34,6 +35,7 @@ public struct FluentPostgreSQLQuery: FluentSQLQuery {
     public var orderBy: [OrderBy]
     public var limit: Int?
     public var offset: Int?
+    public var upsert: PostgreSQLUpsert?
     public var defaultBinaryOperator: GenericSQLBinaryOperator
 
     public static func query(_ statement: Statement, _ table: TableIdentifier) -> FluentPostgreSQLQuery {
@@ -47,6 +49,7 @@ public struct FluentPostgreSQLQuery: FluentSQLQuery {
             orderBy: [],
             limit: nil,
             offset: nil,
+            upsert: nil,
             defaultBinaryOperator: .and
         )
     }

Sources/FluentPostgreSQL/PostgreSQLDatabase+QuerySupporting.swift

@@ -65,6 +65,7 @@ extension PostgreSQLDatabase: QuerySupporting {
                 values.append(row.value)
             }
             insert.values.append(values)
+            insert.upsert = fluent.upsert
             insert.returning.append(.all)
             query = .insert(insert)
         case ._select:

Tests/FluentPostgreSQLTests/FluentPostgreSQLTests.swift

@@ -360,7 +360,23 @@ class FluentPostgreSQLTests: XCTestCase {
         // let earth = try Planet.query(on: conn).filter(\.name, .ilike, "earth").first().wait()
         // XCTAssertEqual(earth?.name, "Earth")
     }
+    
+    func testCreateOrUpdate() throws {
+        let conn = try benchmarker.pool.requestConnection().wait()
+        defer { benchmarker.pool.releaseConnection(conn) }
+        defer { try? Planet.revert(on: conn).wait() }
+        try Planet.prepare(on: conn).wait()
 
+        let a = Planet(id: 1, name: "Mars")
+        let b = Planet(id: 1, name: "Earth")
+
+        _ = try a.create(orUpdate: true, on: conn).wait()
+        _ = try b.create(orUpdate: true, on: conn).wait()
+
+        let c = try Planet.find(1, on: conn).wait()
+        XCTAssertEqual(c?.name, "Earth")
+    }
+    
     static let allTests = [
         ("testMinimumViableModelDeclaration", testMinimumViableModelDeclaration),
         ("testGH24", testGH24),
@@ -374,6 +390,7 @@ class FluentPostgreSQLTests: XCTestCase {
         ("testEmptySubset", testEmptySubset),
         ("testSort", testSort),
         ("testCustomFilter", testCustomFilter),
+        ("testCreateOrUpdate", testCreateOrUpdate),
     ]
 }