gobject-generator/Tests/SwiftGtkGenCoreTests/CFunctionCallTests.swift

import Testing
@testable import SwiftGtkGenCore

@Test("Simple void method calls C function directly")
func testVoidMethodCall() throws {
    let method = Method(name: "show", cIdentifier: "gtk_widget_show",
                        parameters: [
                            Parameter(name: "widget", type: .pointer,
                                      transferOwnership: .none, isInstanceParameter: true)
                        ], returnType: .void)
    let callExpr = CodeGenerator.generateCFunctionCall(method: method, instancePointer: "pointer")
    #expect(callExpr == "gtk_widget_show(pointer)")
}

@Test("String return wraps with String(cString:)")
func testStringReturnCall() throws {
    let method = Method(name: "getLabel", cIdentifier: "gtk_label_get_text",
                        parameters: [
                            Parameter(name: "label", type: .pointer,
                                      transferOwnership: .none, isInstanceParameter: true)
                        ], returnType: .string)
    let callExpr = CodeGenerator.generateCFunctionCall(method: method, instancePointer: "pointer")
    #expect(callExpr == "String(cString: gtk_label_get_text(pointer))")
}

@Test("Bool return uses CInt comparison")
func testBoolReturnCall() throws {
    let method = Method(name: "getVisible", cIdentifier: "gtk_widget_get_visible",
                        parameters: [
                            Parameter(name: "widget", type: .pointer,
                                      transferOwnership: .none, isInstanceParameter: true)
                        ], returnType: .boolean)
    let callExpr = CodeGenerator.generateCFunctionCall(method: method, instancePointer: "pointer")
    #expect(callExpr == "(gtk_widget_get_visible(pointer) != 0)")
}

@Test("GObject pointer parameter uses .pointer property")
func testGObjectParameterCall() throws {
    let method = Method(name: "add", cIdentifier: "gtk_container_add",
                        parameters: [
                            Parameter(name: "container", type: .pointer,
                                      transferOwnership: .none, isInstanceParameter: true),
                            Parameter(name: "child", type: .typeRef("Widget"),
                                      transferOwnership: .none)
                        ], returnType: .void)
    let callExpr = CodeGenerator.generateCFunctionCall(method: method, instancePointer: "pointer")
    #expect(callExpr == "gtk_container_add(pointer, child.pointer)")
}

@Test("TypeRef return wraps in Swift type")
func testTypeRefReturnCall() throws {
    let method = Method(name: "getParent", cIdentifier: "gtk_widget_get_parent",
                        parameters: [
                            Parameter(name: "widget", type: .pointer,
                                      transferOwnership: .none, isInstanceParameter: true)
                        ], returnType: .typeRef("Widget", namespace: "Gtk"))
    let callExpr = CodeGenerator.generateCFunctionCall(method: method, instancePointer: "pointer")
    #expect(callExpr == "Widget(pointer: gtk_widget_get_parent(pointer))")
}

@Test("Void return type produces bare call")
func testVoidReturn() throws {
    let method = Method(name: "show", cIdentifier: "gtk_widget_show",
                        parameters: [
                            Parameter(name: "widget", type: .pointer,
                                      transferOwnership: .none, isInstanceParameter: true)
                        ], returnType: .void)
    let expr = CodeGenerator.generateCFunctionCall(method: method, instancePointer: "pointer")
    #expect(expr == "gtk_widget_show(pointer)")
}

@Test("Optional typeRef parameter uses optional chaining")
func testOptionalTypeRefParameter() throws {
    let method = Method(name: "setParent", cIdentifier: "gtk_widget_set_parent",
                        parameters: [
                            Parameter(name: "widget", type: .pointer,
                                      transferOwnership: .none, isInstanceParameter: true),
                            Parameter(name: "parent", type: .optional(.typeRef("Widget")),
                                      transferOwnership: .none)
                        ], returnType: .void)
    let expr = CodeGenerator.generateCFunctionCall(method: method, instancePointer: "pointer")
    #expect(expr == "gtk_widget_set_parent(pointer, parent?.pointer)")
}

@Test("Optional typeRef return uses map")
func testOptionalTypeRefReturn() throws {
    let method = Method(name: "getChild", cIdentifier: "gtk_widget_get_child",
                        parameters: [
                            Parameter(name: "widget", type: .pointer,
                                      transferOwnership: .none, isInstanceParameter: true)
                        ], returnType: .optional(.typeRef("Widget")))
    let expr = CodeGenerator.generateCFunctionCall(method: method, instancePointer: "pointer")
    #expect(expr == "gtk_widget_get_child(pointer).map { Widget(pointer: $0) }")
}

@Test("Int32 return passes through directly")
func testIntReturn() throws {
    let method = Method(name: "getWidth", cIdentifier: "gtk_widget_get_width",
                        parameters: [
                            Parameter(name: "widget", type: .pointer,
                                      transferOwnership: .none, isInstanceParameter: true)
                        ], returnType: .int32)
    let expr = CodeGenerator.generateCFunctionCall(method: method, instancePointer: "pointer")
    #expect(expr == "gtk_widget_get_width(pointer)")
}

@Test("Filename return wraps with String(cString:)")
func testFilenameReturn() throws {
    let method = Method(name: "getFilename", cIdentifier: "gtk_file_chooser_get_filename",
                        parameters: [
                            Parameter(name: "chooser", type: .pointer,
                                      transferOwnership: .none, isInstanceParameter: true)
                        ], returnType: .filename)
    let expr = CodeGenerator.generateCFunctionCall(method: method, instancePointer: "pointer")
    #expect(expr == "String(cString: gtk_file_chooser_get_filename(pointer))")
}