Support defaults in @Selection.Columns.init

Sources/StructuredQueriesMacros/SelectionMacro.swift

@@ -205,7 +205,7 @@ extension SelectionMacro: MemberMacro {
       return []
     }
     let type = IdentifierTypeSyntax(name: declaration.name.trimmed)
-    var allColumns: [(name: TokenSyntax, type: TypeSyntax?)] = []
+    var allColumns: [(name: TokenSyntax, type: TypeSyntax?, default: ExprSyntax?)] = []
     var decodings: [String] = []
     var decodingUnwrappings: [String] = []
     var decodingAssignments: [String] = []
@@ -278,7 +278,12 @@ extension SelectionMacro: MemberMacro {
           .text
       }
 
-      allColumns.append((identifier, columnQueryValueType))
+      let defaultValue: ExprSyntax? =
+        binding.initializer.map(\.value.trimmed)
+        // TODO: Revisit this with multi-column support.
+        // ?? (columnQueryValueType?.isOptionalType == true ? ExprSyntax(NilLiteralExprSyntax()) : nil)
+
+      allColumns.append((identifier, columnQueryValueType, defaultValue))
       let decodedType = columnQueryValueType?.asNonOptionalType()
       decodings.append(
         """
@@ -320,7 +325,13 @@ extension SelectionMacro: MemberMacro {
 
     let initArguments =
       allColumns
-      .map { "\($0): some \(moduleName).QueryExpression\($1.map { "<\($0)>" } ?? "")" }
+      .map {
+        """
+        \($0): some \(moduleName).QueryExpression\
+        \($1.map { "<\($0)>" } ?? "")\
+        \($2.map { "= #bind(\($0))" } ?? "")
+        """
+      }
       .joined(separator: ",\n")
     let initAssignment: [String] =
       allColumns

Sources/StructuredQueriesSQLiteCore/Documentation.docc/Articles/Triggers.md

@@ -151,20 +151,25 @@ last list was deleted:
 One can use triggers with a `SELECT` action to invoke Swift code when an event occurs in your
 database. For example, suppose you want to execute a Swift function a new reminder is inserted
 into the database. First you must register the function with SQLite and that depends on what
-SQLite driver you are using ([here][grdb-add-function] is how to do it in GRDB).
+SQLite driver you are using ([here][sqlite-data-add-function] is how to do it in SQLiteData).
 
 Suppose we registered a function called `didInsertReminder`, and further suppose it takes one
 argument of the ID of the newly inserted reminder. Then one can invoke this function whenever a
-reminder is inserted into the database with the  following trigger:
+reminder is inserted into the database with the following trigger:
 
-[grdb-add-function]: https://swiftpackageindex.com/groue/grdb.swift/v7.5.0/documentation/grdb/database/add(function:)
+[sqlite-data-add-function]: https://swiftpackageindex.com/pointfreeco/sqlite-data/main/documentation/sqlitedata/database-52hin/add(function:)-1z12a
 
 @Row {
   @Column {
     ```swift
+    @DatabaseFunction
+    func didInsertReminder(_ id: Int) {
+      // ...
+    }
+
     Reminders.createTemporaryTrigger(
       after: .insert { new in
-        #sql("SELECT didInsertReminder(\(new.id))")
+        Values($didInsertReminder(new.id))
       }
     )
     ```
@@ -175,7 +180,7 @@ reminder is inserted into the database with the  following trigger:
     AFTER INSERT ON "reminders"
     FOR EACH ROW
     BEGIN
-      SELECT didInsertReminder("new"."id")
+      SELECT "didInsertReminder"("new"."id")
     END
     ```
   }

Tests/StructuredQueriesMacrosTests/SelectionMacroTests.swift

@@ -143,5 +143,50 @@ extension SnapshotTests {
         """
       }
     }
+
+    @Test func defaults() {
+      assertMacro {
+        """
+        @Selection struct Row {
+          var title = ""
+          @Column(as: [String].JSONRepresentation.self)
+          var notes: [String] = []
+        }
+        """
+      } expansion: {
+        """
+        struct Row {
+          var title = ""
+          var notes: [String] = []
+
+          public struct Columns: StructuredQueriesCore._SelectedColumns {
+            public typealias QueryValue = Row
+            public let selection: [(aliasName: String, expression: StructuredQueriesCore.QueryFragment)]
+            public init(
+              title: some StructuredQueriesCore.QueryExpression<Swift.String> = StructuredQueriesCore.BindQueryExpression(""),
+              notes: some StructuredQueriesCore.QueryExpression<[String].JSONRepresentation> = StructuredQueriesCore.BindQueryExpression([])
+            ) {
+              self.selection = [("title", title.queryFragment), ("notes", notes.queryFragment)]
+            }
+          }
+        }
+
+        extension Row: StructuredQueriesCore._Selection {
+          public init(decoder: inout some StructuredQueriesCore.QueryDecoder) throws {
+            let title = try decoder.decode(Swift.String.self)
+            let notes = try decoder.decode([String].JSONRepresentation.self)
+            guard let title else {
+              throw QueryDecodingError.missingRequiredColumn
+            }
+            guard let notes else {
+              throw QueryDecodingError.missingRequiredColumn
+            }
+            self.title = title
+            self.notes = notes
+          }
+        }
+        """
+      }
+    }
   }
 }