conjure/Tests/ConjureKitTests/NoteMarkdownExportTests.swift

import AppKit
import ConjureKit
import Testing

@Test @MainActor
func markdownExportPreservesWholeTextAndSnapshotsBeforeWriting() throws {
    let directory = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
    defer { try? FileManager.default.removeItem(at: directory) }
    try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: false)
    let text = "\n日本語 🦊  \r\nplain and code\nordinary task\n\u{fffc}\n"
    let source = NSMutableAttributedString(string: text)
    source.addAttribute(.attachment, value: NSTextAttachment(), range: NSRange(location: 0, length: 1))
    let export = try NoteMarkdownExport(contents: source)
    #expect(!export.hasImages)
    #expect(export.clipboardText == text)
    #expect(source.string == text)
    source.mutableString.setString("Edited after export began")
    let file = directory.appendingPathComponent("Note.md")
    try Data("old file".utf8).write(to: file)
    try export.write(to: file)
    #expect(try Data(contentsOf: file) == Data(text.utf8))
    #expect(try FileManager.default.contentsOfDirectory(atPath: directory.path) == ["Note.md"])
}

@Test @MainActor
func markdownExportWritesOriginalImageBytesAndEscapedLinksWithoutChangingSource() throws {
    let directory = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
    defer { try? FileManager.default.removeItem(at: directory) }
    let png = try markdownExportPNG()
    let wrapper = FileWrapper(regularFileWithContents: png)
    let name = "pixel [x] `1` #%.png"
    wrapper.preferredFilename = name
    let originalFilename = wrapper.filename
    let attachment = NSTextAttachment(fileWrapper: wrapper)
    let source = NSMutableAttributedString(attributedString: NoteDocument.importMarkdown(NSAttributedString(string: "\n# 🦊\n")))
    source.append(NSAttributedString(attachment: attachment))
    source.append(NoteDocument.importMarkdown(NSAttributedString(string: "\n- [ ] todo  \n")))
    let before = NSAttributedString(attributedString: source)
    let export = try NoteMarkdownExport(contents: source)
    #expect(export.hasImages)
    #expect(export.clipboardText == "\n# 🦊\n``<pixel [x] `1` #%.png>``\n- [ ] todo  \n")
    #expect(source.isEqual(to: before))
    #expect(wrapper.preferredFilename == name)
    #expect(wrapper.filename == originalFilename)
    #expect(wrapper.regularFileContents == png)
    source.mutableString.setString("Changed")
    wrapper.preferredFilename = "changed.png"
    try export.write(to: directory)
    let markdown = "\n# 🦊\n![pixel \\[x\\] \\`1\\` #%.png](pixel%20%5Bx%5D%20%601%60%20%23%25.png)\n- [ ] todo  \n"
    #expect(try String(contentsOf: directory.appendingPathComponent("note.md"), encoding: .utf8) == markdown)
    #expect(try Data(contentsOf: directory.appendingPathComponent(name)) == png)
    #expect(Set(try FileManager.default.contentsOfDirectory(atPath: directory.path)) == ["note.md", name])
}

@Test @MainActor
func markdownExportUsesSafeUniqueImageNamesAndReservesMarkdownFile() throws {
    let directory = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
    defer { try? FileManager.default.removeItem(at: directory) }
    let png = try markdownExportPNG()
    let names = ["same.png", "SAME.png", "../escape.png", "note.md", "CON.png", "bad\\name.png"]
    let source = NSMutableAttributedString(string: "")
    var wrappers: [FileWrapper] = []
    for name in names {
        let wrapper = FileWrapper(regularFileWithContents: png)
        wrapper.preferredFilename = name
        wrappers.append(wrapper)
        source.append(NSAttributedString(attachment: NSTextAttachment(fileWrapper: wrapper)))
        source.append(NSAttributedString(string: "\n"))
    }
    let expected = ["same.png", "SAME-2.png", "image-3.png", "note.png", "image-5.png", "image-6.png"]
    let export = try NoteMarkdownExport(contents: source)
    #expect(export.clipboardText == expected.map { "`<\($0)>`\n" }.joined())
    #expect(wrappers.map(\.preferredFilename) == names.map(Optional.some))
    try export.write(to: directory)
    #expect(try String(contentsOf: directory.appendingPathComponent("note.md"), encoding: .utf8) == expected.map { "![\($0)](\($0))\n" }.joined())
    #expect(Set(try FileManager.default.contentsOfDirectory(atPath: directory.path)) == Set(expected + ["note.md"]))
    for name in expected {
        #expect(try Data(contentsOf: directory.appendingPathComponent(name)) == png)
    }
}

@Test @MainActor
func markdownExportPreservesExistingDirectoryAndRemovesFailedStagingDirectory() throws {
    let root = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
    defer { try? FileManager.default.removeItem(at: root) }
    let existing = root.appendingPathComponent("Existing")
    try FileManager.default.createDirectory(at: existing, withIntermediateDirectories: true)
    let marker = existing.appendingPathComponent("keep.txt")
    let saved = Data("User data".utf8)
    try saved.write(to: marker)
    let wrapper = FileWrapper(regularFileWithContents: try markdownExportPNG())
    wrapper.preferredFilename = "pixel.png"
    let export = try NoteMarkdownExport(contents: NSAttributedString(attachment: NSTextAttachment(fileWrapper: wrapper)))
    #expect(throws: (any Error).self) { try export.write(to: existing) }
    #expect(try Data(contentsOf: marker) == saved)
    #expect(try FileManager.default.contentsOfDirectory(atPath: existing.path) == ["keep.txt"])
    let invalidDestination = root.appendingPathComponent(String(repeating: "x", count: 256))
    #expect(throws: (any Error).self) { try export.write(to: invalidDestination) }
    #expect(try FileManager.default.contentsOfDirectory(atPath: root.path) == ["Existing"])
}

@Test @MainActor
func markdownExportSupportsNativeImageOnlyAttachmentsAndRejectsUnreadableAttachments() throws {
    let directory = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
    defer { try? FileManager.default.removeItem(at: directory) }
    let image = try #require(NSImage(data: markdownExportPNG()))
    let attachment = NSTextAttachment()
    attachment.attachmentCell = NSTextAttachmentCell(imageCell: image)
    #expect(attachment.fileWrapper == nil)
    let export = try NoteMarkdownExport(contents: NSAttributedString(attachment: attachment))
    #expect(export.clipboardText == "`<image-1.png>`")
    try export.write(to: directory)
    let data = try Data(contentsOf: directory.appendingPathComponent("image-1.png"))
    #expect(NSBitmapImageRep(data: data)?.pixelsWide == 1)
    #expect(NSBitmapImageRep(data: data)?.pixelsHigh == 1)
    for wrapper in [FileWrapper(regularFileWithContents: Data("not an image".utf8)), FileWrapper(directoryWithFileWrappers: [:])] {
        let source = NSAttributedString(attachment: NSTextAttachment(fileWrapper: wrapper))
        #expect(throws: (any Error).self) { try NoteMarkdownExport(contents: source) }
        #expect(source.string == "\u{fffc}")
    }
}

@MainActor
private func markdownExportPNG() throws -> Data {
    let bitmap = try #require(NSBitmapImageRep(
        bitmapDataPlanes: nil, pixelsWide: 1, pixelsHigh: 1,
        bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false,
        colorSpaceName: .deviceRGB, bytesPerRow: 0, bitsPerPixel: 0
    ))
    bitmap.setColor(.red, atX: 0, y: 0)
    return try #require(bitmap.representation(using: .png, properties: [:]))
}