#shell/workspace

#Contracts

• SourcePath normalizes root-relative paths and rejects absolute paths, traversal, Windows drive paths, and NUL bytes. infer_language_id maps common source extensions.
• FileSystemProvider exposes scheme-owned text reads and watches; read_document/watch_file adapt it to structured results and snapshots.
• DocumentProvider exposes document-level read, watch, and close. Watches may invalidate, update, delete, or fail a URI.
• DocumentSnapshot is immutable provider/transport data: URI, metadata, revision, text, UTF-16 offsets, LF/CRLF/lone-CR line splitting, and 1-based Position conversion.
• WorkspaceTreeProvider exposes a root URI and pull-based one-level resolve; unresolved directory stats carry children: None.

#SourcePath

///|
fn source_path(raw : String) -> String {
  match @workspace.SourcePath::normalize_root_relative_path(raw) {
    ParsedSourcePath(path) => "ok:" + path.to_string()
    SourcePathError(_) => "rejected"
  }
}

///|
test "traversal, absolute, and drive paths are rejected" {
  debug_inspect(
    [
      "src/main.mbt", "./src/main.mbt", "src//main.mbt", "../escape.mbt", "/etc/passwd",
      "C:\\Windows\\system.ini", "src/\u{0}evil.mbt",
    ].map(source_path),
    content=(
      #|[
      #|  "ok:src/main.mbt",
      #|  "ok:src/main.mbt",
      #|  "ok:src/main.mbt",
      #|  "rejected",
      #|  "rejected",
      #|  "rejected",
      #|  "rejected",
      #|]
    ),
  )
}

• an unrecognized name falls back to moonbit rather than to plaintext, so a moonbit language id is not evidence that the host recognized the file;
• notes.mbt.md infers moonbit, not markdown, because the .mbt extension matches first.

///|
test "language ids are inferred from the extension" {
  debug_inspect(
    ["main.mbt", "data.json", "app.js", "README.md", "notes.mbt.md", "LICENSE"].map(
      @workspace.infer_language_id,
    ),
    content=(
      #|["moonbit", "json", "javascript", "markdown", "moonbit", "moonbit"]
    ),
  )
}

#DocumentSnapshot

///|
fn snapshot(text : String) -> @workspace.DocumentSnapshot raise {
  DocumentSnapshot(
    @base_common.Uri::parse("file:///workspace/src/main.mbt"),
    "main.mbt",
    "moonbit",
    "rev-1",
    text,
  )
}

///|
test "line addressing handles all three terminators" {
  let doc = snapshot("a\r\nbb\rccc\ndddd")
  debug_inspect(
    (
      doc.line_count(),
      [
        for index in 0..<doc.line_count() => doc.line_text(index)
      ],
      doc.length(),
    ),
    content=(
      #|(4, ["a", "bb", "ccc", "dddd"], 14)
    ),
  )
}

///|
test "offsets and 1-based positions convert both ways" {
  let doc = snapshot("let x = 1\nlet y = 2\n")
  let position = doc.position_at_offset(12)
  debug_inspect(
    (
      position,
      doc.offset_at_position(position),
      doc.line_at_offset(12),
      doc.slice(OffsetRange(10, 13)),
    ),
    content=(
      #|({ line_number: 2, column: 3 }, 12, 1, "let")
    ),
  )
}

///|
test "the revision is derived from the text" {
  let first = @workspace.revision_from_text("let x = 1\n")
  let same = @workspace.revision_from_text("let x = 1\n")
  let different = @workspace.revision_from_text("let x = 2\n")
  debug_inspect(
    (first == same, first == different),
    content=(
      #|(true, false)
    ),
  )
}

#Boundary and validation