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/*
This source file is part of the Swift.org open source project
Copyright 2016 Apple Inc. and the Swift project authors
Licensed under Apache License v2.0 with Runtime Library Exception
See http://swift.org/LICENSE.txt for license information
See http://swift.org/CONTRIBUTORS.txt for Swift project authors
*/
import XCTest
import TSCBasic
import TSCTestSupport
import TSCUtility
fileprivate class Foo: SimplePersistanceProtocol {
var int: Int
var path: AbsolutePath
let persistence: SimplePersistence
init(int: Int, path: AbsolutePath, fileSystem: FileSystem) {
self.int = int
self.path = path
self.persistence = SimplePersistence(
fileSystem: fileSystem,
schemaVersion: 1,
supportedSchemaVersions: [0],
statePath: AbsolutePath.root.appending(components: "subdir", "state.json")
)
}
func restore(from json: JSON) throws {
self.int = try json.get("int")
self.path = try AbsolutePath(validating: json.get("path"))
}
func restore(from json: JSON, supportedSchemaVersion: Int) throws {
switch supportedSchemaVersion {
case 0:
self.int = try json.get("old_int")
self.path = try AbsolutePath(validating: json.get("old_path"))
default:
fatalError()
}
}
func toJSON() -> JSON {
return JSON([
"int": int,
"path": path,
])
}
func save() throws {
try persistence.saveState(self)
}
func restore() throws -> Bool {
return try persistence.restoreState(self)
}
}
fileprivate enum Bar {
class V1: SimplePersistanceProtocol {
var int: Int
let persistence: SimplePersistence
init(int: Int, fileSystem: FileSystem) {
self.int = int
self.persistence = SimplePersistence(
fileSystem: fileSystem,
schemaVersion: 1,
statePath: AbsolutePath.root.appending(components: "subdir", "state.json")
)
}
func restore(from json: JSON) throws {
self.int = try json.get("int")
}
func toJSON() -> JSON {
return JSON([
"int": int,
])
}
}
class V2: SimplePersistanceProtocol {
var int: Int
var string: String
let persistence: SimplePersistence
init(int: Int, string: String, fileSystem: FileSystem) {
self.int = int
self.string = string
self.persistence = SimplePersistence(
fileSystem: fileSystem,
schemaVersion: 1,
statePath: AbsolutePath.root.appending(components: "subdir", "state.json")
)
}
func restore(from json: JSON) throws {
self.int = try json.get("int")
self.string = try json.get("string")
}
func toJSON() -> JSON {
return JSON([
"int": int,
"string": string
])
}
}
}
class SimplePersistenceTests: XCTestCase {
func testBasics() throws {
let fs = InMemoryFileSystem()
let stateFile = AbsolutePath.root.appending(components: "subdir", "state.json")
let foo = Foo(int: 1, path: "/hello", fileSystem: fs)
// Restoring right now should return false because state is not present.
XCTAssertFalse(try foo.restore())
// Save and check saved data.
try foo.save()
let json = try JSON(bytes: fs.readFileContents(stateFile))
XCTAssertEqual(1, try json.get("version"))
XCTAssertEqual(foo.toJSON(), try json.get("object"))
// Modify local state and restore.
foo.int = 5
XCTAssertTrue(try foo.restore())
XCTAssertEqual(foo.int, 1)
XCTAssertEqual(foo.path, "/hello")
// Modify state's schema version.
let newJSON = JSON(["version": 2])
try fs.writeFileContents(stateFile, bytes: newJSON.toBytes())
do {
_ = try foo.restore()
XCTFail()
} catch {
let error = String(describing: error)
XCTAssert(error.contains("unsupported schema version 2"), error)
}
}
func testBackwardsCompatibleStateFile() throws {
// Test that we don't overwrite the json in case we find keys we don't need.
let fs = InMemoryFileSystem()
let stateFile = AbsolutePath.root.appending(components: "subdir", "state.json")
// Create and save v2 object.
let v2 = Bar.V2(int: 100, string: "hello", fileSystem: fs)
try v2.persistence.saveState(v2)
// Restore v1 object from v2 file.
let v1 = Bar.V1(int: 1, fileSystem: fs)
XCTAssertEqual(v1.int, 1)
XCTAssertTrue(try v1.persistence.restoreState(v1))
XCTAssertEqual(v1.int, 100)
// Check state file still has the old "string" key.
let json = try JSON(bytes: fs.readFileContents(stateFile))
XCTAssertEqual("hello", try json.get("object").get("string"))
// Update a value in v1 object and save.
v1.int = 500
try v1.persistence.saveState(v1)
v2.string = ""
// Now restore v2 and expect string to be present as well as the updated int value.
XCTAssertTrue(try v2.persistence.restoreState(v2))
XCTAssertEqual(v2.int, 500)
XCTAssertEqual(v2.string, "hello")
}
func testCanLoadFromOldSchema() throws {
let fs = InMemoryFileSystem()
let stateFile = AbsolutePath.root.appending(components: "subdir", "state.json")
try fs.writeFileContents(stateFile) {
$0.send("""
{
"version": 0,
"object": {
"old_path": "/oldpath",
"old_int": 4
}
}
""")
}
let foo = Foo(int: 1, path: "/hello", fileSystem: fs)
XCTAssertEqual(foo.path, "/hello")
XCTAssertEqual(foo.int, 1)
// Load from an older but supported schema state file.
XCTAssertTrue(try foo.restore())
XCTAssertEqual(foo.path, "/oldpath")
XCTAssertEqual(foo.int, 4)
}
}
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