container/Tests/ContainerizationEXT4Tests/TestEXT4Format+Create.swift

//===----------------------------------------------------------------------===//
// Copyright © 2025-2026 Apple Inc. and the Containerization project authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//===----------------------------------------------------------------------===//

//

import Foundation
import SystemPackage
import Testing

@testable import ContainerizationEXT4

struct Ext4FormatCreateTests {
    @Test func fileReplace() throws {
        let fsPath = FilePath(
            FileManager.default.temporaryDirectory
                .appendingPathComponent(UUID().uuidString, isDirectory: false))
        defer { try? FileManager.default.removeItem(at: fsPath.url) }

        let formatter = try EXT4.Formatter(fsPath, minDiskSize: 32.kib())
        defer { try? formatter.close() }
        try formatter.create(path: FilePath("/file"), mode: EXT4.Inode.Mode(.S_IFREG, 0o755), buf: nil)  // create a regular file
        #expect(throws: Never.self) {
            try formatter.create(path: FilePath("/file"), mode: EXT4.Inode.Mode(.S_IFREG, 0o755), buf: nil)
        }  // overwrite it with a regular file
        #expect(throws: Error.self) { try formatter.create(path: FilePath("/file"), mode: EXT4.Inode.Mode(.S_IFDIR, 0o700)) }  // overwrite it with a directory
    }

    @Test func dirReplace() throws {
        let fsPath = FilePath(
            FileManager.default.temporaryDirectory
                .appendingPathComponent(UUID().uuidString, isDirectory: false))
        defer { try? FileManager.default.removeItem(at: fsPath.url) }

        let formatter = try EXT4.Formatter(fsPath, minDiskSize: 32.kib())
        defer { try? formatter.close() }
        try formatter.create(path: FilePath("/dir"), mode: EXT4.Inode.Mode(.S_IFDIR, 0o700))  // create a directory
        #expect(throws: Never.self) {
            try formatter.create(path: FilePath("/dir"), mode: EXT4.Inode.Mode(.S_IFDIR, 0o700))
        }  // overwrite it with a directory
        #expect(throws: Error.self) { try formatter.create(path: FilePath("/dir"), mode: EXT4.Inode.Mode(.S_IFREG, 0o755)) }  // overwrite it with a file
    }

    @Test func fileParentFails() throws {
        let fsPath = FilePath(
            FileManager.default.temporaryDirectory
                .appendingPathComponent(UUID().uuidString, isDirectory: false))
        defer { try? FileManager.default.removeItem(at: fsPath.url) }

        let formatter = try EXT4.Formatter(fsPath, minDiskSize: 32.kib())
        defer { try? formatter.close() }
        try formatter.create(path: FilePath("/file"), mode: EXT4.Inode.Mode(.S_IFREG, 0o755), buf: nil)  // create a regular file
        #expect(throws: Error.self) { try formatter.create(path: FilePath("/file/dir"), mode: EXT4.Inode.Mode(.S_IFDIR, 0o700)) }  // create a subdir in a file?
    }

    @Test func createParentAutomatically() throws {
        let fsPath = FilePath(
            FileManager.default.temporaryDirectory
                .appendingPathComponent(UUID().uuidString, isDirectory: false))
        defer { try? FileManager.default.removeItem(at: fsPath.url) }

        let formatter = try EXT4.Formatter(fsPath, minDiskSize: 32.kib())
        defer { try? formatter.close() }
        #expect(throws: Never.self) {
            try formatter.create(path: FilePath("/parent/file"), mode: EXT4.Inode.Mode(.S_IFREG, 0o755), buf: nil)
        }  // should create /parent automatically
    }
}

@Suite(.serialized)
struct NegativeTimestampRoundtripTests {
    private let fsPath = FilePath(
        FileManager.default.temporaryDirectory
            .appendingPathComponent("ext4-pre1970-roundtrip.img", isDirectory: false))
    private let apollo11MoonLanding: Date = {
        let f = ISO8601DateFormatter()
        f.formatOptions = [.withInternetDateTime, .withFractionalSeconds]
        return f.date(from: "1969-07-20T20:17:39.9Z")!
    }()

    @Test func encodeNegativeTimestamp() throws {
        let formatter = try EXT4.Formatter(fsPath, minDiskSize: 32.kib())
        defer { try? formatter.close() }
        let ts = FileTimestamps(access: apollo11MoonLanding, modification: apollo11MoonLanding, creation: apollo11MoonLanding)
        try formatter.create(path: FilePath("/file"), mode: EXT4.Inode.Mode(.S_IFREG, 0o755), ts: ts, buf: nil)
    }

    @Test func decodeNegativeTimestamp() throws {
        let reader = try EXT4.EXT4Reader(blockDevice: fsPath)
        let (_, inode) = try reader.stat(FilePath("/file"))
        let mtime = Date(fsTimestamp: UInt64(inode.mtime) | (UInt64(inode.mtimeExtra) << 32))
        let atime = Date(fsTimestamp: UInt64(inode.atime) | (UInt64(inode.atimeExtra) << 32))
        let crtime = Date(fsTimestamp: UInt64(inode.crtime) | (UInt64(inode.crtimeExtra) << 32))
        #expect(mtime == apollo11MoonLanding)
        #expect(atime == apollo11MoonLanding)
        #expect(crtime == apollo11MoonLanding)
    }
}