pythonnative/src/pythonnative/testing/backend.py at main · pythonnative/pythonnative · GitHub

History

548 lines (474 loc) · 22.3 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

"""In-memory backend implementing the batched mutation protocol.

[`FakeBackend`][pythonnative.testing.FakeBackend] speaks the same

protocol as the platform registries (``apply_mutations``,

``resolve_view``, ``measure_intrinsic``, ``command``, plus the animation

hooks) while keeping a real tree of

[`FakeView`][pythonnative.testing.FakeView] objects, so tests can assert

on structure, props, and frames without a device.

The fake raises on malformed transactions, including unknown tags, double

destroys, and insertion into a destroyed parent. Production bridge renderers

validate versioned commits before mutation and fail the surface on rejection.

Recorded op shapes (in ``FakeBackend.ops``):

- ``("create", type_name, view.id)``

- ``("update", type_name, view.id, tuple(sorted(changed_keys)))``

- ``("insert_child", parent.id, child.id, index)``

- ``("destroy", view.id)``

- ``("set_frame", view.id, x, y, w, h)``

Imperative commands (``FakeBackend.command``) are recorded in

``FakeBackend.commands`` and answered for the view types that have typed

handles: ``TextInput`` (``get_value``, ``focus``, ``blur``, ``clear``,

``select_all``, ``set_selection``), ``ScrollView`` (``scroll_to_offset``,

``scroll_to_end``, ``get_scroll_offset``), ``WebView`` (``can_go_back``,

``can_go_forward``, ``get_url``, ``get_title``, ``load_url``, and the

navigation verbs), and ``VirtualList`` (``scroll_to_index``,

``scroll_to_end``).

"""

from __future__ import annotations

from typing import Any, Dict, Iterator, List, Optional, Sequence, Tuple

from ..mutations import CreateOp, DestroyOp, InsertOp, Mutation, SetFrameOp, UpdateOp

__all__ = ["DEFAULT_INTRINSIC", "IMPLICIT_ROLES", "FakeBackend", "FakeView"]

DEFAULT_INTRINSIC: Dict[str, Tuple[float, float]] = {

"Text": (60.0, 16.0),

"Button": (80.0, 32.0),

"Image": (40.0, 40.0),

"TextInput": (120.0, 32.0),

"TabBar": (320.0, 49.0),

}

"""Intrinsic sizes reported for content-sized leaves (what platform measure hooks would return)."""

IMPLICIT_ROLES: Dict[str, str] = {

"Button": "button",

"Pressable": "button",

"Picker": "button",

"DatePicker": "button",

"Switch": "switch",

"Checkbox": "checkbox",

"TextInput": "textbox",

"Image": "image",

"ImageBackground": "image",

"Slider": "adjustable",

"ProgressBar": "progressbar",

}

"""Accessibility role each native type implies when no ``accessibility_role`` prop is set.

``get_by_role`` consults this table after the explicit prop, so

``pn.Button("Save")`` matches ``get_by_role("button")`` and

``pn.Switch()`` matches ``get_by_role("switch")``. ``Text`` has no

implicit role; ``pn.Text("Title", accessibility_role="header")`` matches

``get_by_role("header")`` through the prop.

"""

class FakeView:

"""Simulated native view: type, props, children, and last frame.

Attributes:

tag: The reconciler-assigned tag (use with ``fire`` / events).

type_name: Native type, e.g. ``"Text"``.

props: Native-safe props (event callbacks are stripped; they

live in the event registry keyed by ``tag``).

children: Child views in order.

frame: ``(x, y, width, height)`` from the last layout pass.

"""

_next_id = 0

def __init__(self, tag: int, type_name: str, props: Dict[str, Any]) -> None:

FakeView._next_id += 1

self.id = FakeView._next_id

self.tag = tag

self.type_name = type_name

self.props: Dict[str, Any] = dict(props)

self.children: List[FakeView] = []

self.parent: Optional[FakeView] = None

self.frame: Tuple[float, float, float, float] = (0.0, 0.0, 0.0, 0.0)

self.destroyed = False

def __repr__(self) -> str:

suffix = ""

if self.text:

suffix = f" {self.text!r}"

elif self.value:

suffix = f" value={self.value!r}"

elif self.placeholder:

suffix = f" placeholder={self.placeholder!r}"

return f"<{self.type_name} tag={self.tag}{suffix}>"

# -- content --------------------------------------------------------

@property

def text(self) -> Optional[str]:

"""Visible static text: ``Text.text`` or ``Button.title``.

A ``TextInput``'s contents are exposed separately as ``value`` and

``placeholder`` so ``get_by_text`` never matches a form field.

"""

for key in ("text", "title"):

value = self.props.get(key)

if isinstance(value, str):

return value

return None

@property

def placeholder(self) -> Optional[str]:

"""The ``placeholder`` prop of a ``TextInput`` (or ``Picker``), if set."""

value = self.props.get("placeholder")

return value if isinstance(value, str) else None

@property

def value(self) -> Optional[str]:

"""The string ``value`` prop (a ``TextInput``'s display value), if set."""

value = self.props.get("value")

return value if isinstance(value, str) else None

@property

def role(self) -> Optional[str]:

"""Effective accessibility role: the ``accessibility_role`` prop, else the type's implicit role.

See [`IMPLICIT_ROLES`][pythonnative.testing.IMPLICIT_ROLES] for

the implicit table.

"""

explicit = self.props.get("accessibility_role")

if isinstance(explicit, str):

return explicit

return IMPLICIT_ROLES.get(self.type_name)

@property

def accessible_name(self) -> Optional[str]:

"""What assistive technology would announce for this view.

The ``accessibility_label`` prop wins; otherwise the view's own

text or title, a ``Checkbox``'s ``label``, and finally the text

of descendant views joined with single spaces (so a

``Pressable`` wrapping ``Text("Save")`` is named ``"Save"``).

"""

if self.label is not None:

return self.label

if self.text is not None:

return self.text

inline = self.props.get("label")

if isinstance(inline, str):

return inline

parts = [child.text for child in self.walk() if child is not self and child.text]

return " ".join(parts) if parts else None

@property

def disabled(self) -> bool:

"""Whether the view is disabled via the ``disabled`` prop or ``accessibility_state``."""

if self.props.get("disabled"):

return True

state = self.props.get("accessibility_state")

return bool(isinstance(state, dict) and state.get("disabled"))

@property

def hidden(self) -> bool:

"""Whether this view is removed from layout (``display: "none"``)."""

return self.props.get("display") == "none" or self.type_name == "Screen" and self.props.get("active") is False

@property

def test_id(self) -> Optional[str]:

"""The ``test_id`` prop, if set."""

return self.props.get("test_id")

@property

def label(self) -> Optional[str]:

"""The ``accessibility_label`` prop, if set."""

return self.props.get("accessibility_label")

# -- traversal ------------------------------------------------------

def walk(self, *, include_hidden: bool = True) -> Iterator["FakeView"]:

"""Yield this view and every descendant, depth-first.

With ``include_hidden=False`` subtrees under a ``display: "none"``

view are skipped (what a user can see).

"""

if not include_hidden and self.hidden:

return

yield self

for child in self.children:

yield from child.walk(include_hidden=include_hidden)

def find_all(self, predicate_or_type: Any) -> List["FakeView"]:

"""Every view in this subtree matching a type name or predicate."""

if isinstance(predicate_or_type, str):

wanted = predicate_or_type

def predicate(v: "FakeView") -> bool:

return v.type_name == wanted

else:

predicate = predicate_or_type

return [v for v in self.walk() if predicate(v)]

def find_first(self, predicate_or_type: Any) -> Optional["FakeView"]:

"""Return the first view in this subtree matching a type name or predicate, or ``None``."""

found = self.find_all(predicate_or_type)

return found[0] if found else None

def dump(self, indent: int = 0) -> str:

"""Indented, human-readable subtree (for failing-test output)."""

line = " " * indent + repr(self)

x, y, w, h = self.frame

if w or h:

line += f" @({x:g},{y:g} {w:g}x{h:g})"

return "\n".join([line, *(c.dump(indent + 2) for c in self.children)])

class FakeBackend:

"""Tag-table backend recording one tuple per applied mutation.

Args:

intrinsic: Override the intrinsic sizes used by

``measure_intrinsic`` (defaults to

[`DEFAULT_INTRINSIC`][pythonnative.testing.backend.DEFAULT_INTRINSIC]).

"""

def __init__(self, intrinsic: Optional[Dict[str, Tuple[float, float]]] = None) -> None:

self.intrinsic = dict(DEFAULT_INTRINSIC if intrinsic is None else intrinsic)

self.views: Dict[int, FakeView] = {}

self.ops: List[Any] = []

self.batches: List[List[Any]] = []

self.measure_calls: List[int] = []

self.commands: List[Tuple[int, str, Dict[str, Any]]] = []

self.animated: List[Tuple[int, str, Any]] = []

self.list_stores: dict[int, Any] = {}

self.last_create_props: Dict[str, Any] = {}

self.last_update_changes: Dict[str, Any] = {}

self.focused_tag: Optional[int] = None

"""Tag of the ``TextInput`` that last received ``focus`` (``None`` after ``blur``)."""

self.selections: Dict[int, Tuple[int, int]] = {}

"""``(start, end)`` selection per ``TextInput`` tag, set by ``set_selection`` and ``select_all``."""

self.scroll_offsets: Dict[int, Dict[str, float]] = {}

"""Content offset per ``ScrollView`` tag, updated by ``scroll_to_offset`` and ``scroll_to_end``."""

# ------------------------------------------------------------------

# Commit channel

# ------------------------------------------------------------------

def apply_mutations(self, ops: Sequence[Mutation]) -> None:

"""Apply one committed batch to the view tree, recording each op in ``ops`` and ``batches``.

Raises ``AssertionError`` on malformed transactions (unknown tags, double creates or destroys).

"""

batch: List[Any] = []

for op in ops:

recorded = self._apply_one(op)

self.ops.append(recorded)

batch.append(recorded)

self.batches.append(batch)

def _apply_one(self, op: Mutation) -> Tuple[Any, ...]:

if isinstance(op, CreateOp):

if op.tag in self.views:

raise AssertionError(f"create: tag {op.tag} already registered")

view = FakeView(op.tag, op.type_name, op.props)

self.views[op.tag] = view

if op.type_name == "VirtualList":

from ..bridge.list_store import ListStore

store = self.list_stores[op.tag] = ListStore()

if "dataset" in op.props:

store.apply(op.props["dataset"])

self.last_create_props = dict(op.props)

return ("create", op.type_name, view.id)

if isinstance(op, UpdateOp):

view = self._require(op.tag, "update")

from ..mutations import UNSET

for key, value in op.changed_props.items():

if value is UNSET:

view.props.pop(key, None)

else:

view.props[key] = value

if view.type_name == "VirtualList" and "dataset" in op.changed_props:

self.list_stores[op.tag].apply(op.changed_props["dataset"])

self.last_update_changes = dict(op.changed_props)

return ("update", view.type_name, view.id, tuple(sorted(op.changed_props)))

if isinstance(op, InsertOp):

parent = self._require(op.parent_tag, "insert_child")

child = self._require(op.child_tag, "insert_child")

if child.parent is not None:

child.parent.children.remove(child)

child.parent = None

index = max(0, min(op.index, len(parent.children)))

parent.children.insert(index, child)

child.parent = parent

return ("insert_child", parent.id, child.id, index)

if isinstance(op, DestroyOp):

if op.tag not in self.views:

raise AssertionError(f"destroy: unknown tag {op.tag}")

view = self.views.pop(op.tag)

if view.parent is not None:

view.parent.children.remove(view)

view.parent = None

view.destroyed = True

self.list_stores.pop(op.tag, None)

self.selections.pop(op.tag, None)

self.scroll_offsets.pop(op.tag, None)

if self.focused_tag == op.tag:

self.focused_tag = None

return ("destroy", view.id)

if isinstance(op, SetFrameOp):

view = self._require(op.tag, "set_frame")

view.frame = (op.x, op.y, op.width, op.height)

return ("set_frame", view.id, op.x, op.y, op.width, op.height)

raise AssertionError(f"unknown mutation op: {op!r}")

def _require(self, tag: int, op_name: str) -> FakeView:

view = self.views.get(tag)

if view is None:

raise AssertionError(f"{op_name}: unknown tag {tag}")

return view

# ------------------------------------------------------------------

# Imperative escape hatches

# ------------------------------------------------------------------

def resolve_view(self, tag: int) -> Optional[FakeView]:

"""Return the live view registered under ``tag``, or ``None``."""

return self.views.get(tag)

def measure_intrinsic(self, tag: int, max_width: float, max_height: float) -> Tuple[float, float]:

"""Return the configured intrinsic size for the view's type and record the call in ``measure_calls``.

Unknown tags and types without an entry measure as ``(0.0, 0.0)``; the constraints are ignored.

"""

view = self.views.get(tag)

if view is None:

return (0.0, 0.0)

self.measure_calls.append(view.id)

return self.intrinsic.get(view.type_name, (0.0, 0.0))

def command(self, tag: int, name: str, args: Optional[Dict[str, Any]] = None) -> Any:

"""Record an imperative view command in ``commands`` and answer it for known view types.

``TextInput``: ``get_value`` returns the ``value`` prop; ``focus``

and ``blur`` track ``focused_tag`` and fire ``on_focus`` /

``on_blur`` when the app wired them; ``clear`` empties the value;

``select_all`` and ``set_selection(start, end)`` record

``selections``. ``ScrollView``: ``scroll_to_offset(x, y)`` and

``scroll_to_end`` update ``scroll_offsets``; ``get_scroll_offset``

returns ``{"x": ..., "y": ...}``. ``WebView``: ``can_go_back`` and

``can_go_forward`` are ``False``, ``get_url`` returns the ``url``

prop, ``load_url(url)`` replaces it, ``get_title`` is ``None``.

``VirtualList``: ``scroll_to_index`` and ``scroll_to_end`` drive

the list request protocol. Anything else returns ``None``.

"""

arguments = dict(args or {})

self.commands.append((tag, name, arguments))

view = self.views.get(tag)

if view is None:

return None

if view.type_name == "VirtualList":

if name == "scroll_to_index":

self.request_list(tag, int(arguments["index"]))

elif name == "scroll_to_end":

self.request_list(tag, max(0, len(self.list_stores[tag].keys) - 1))

return None

if view.type_name == "TextInput":

return self._text_input_command(view, name, arguments)

if view.type_name == "ScrollView":

return self._scroll_view_command(view, name, arguments)

if view.type_name == "WebView":

return self._web_view_command(view, name, arguments)

return None

def _text_input_command(self, view: FakeView, name: str, arguments: Dict[str, Any]) -> Any:

from ..events import dispatch_event

value = view.value or ""

if name == "get_value":

return value

if name == "focus":

previous = self.focused_tag

self.focused_tag = view.tag

if previous is not None and previous != view.tag and previous in self.views:

dispatch_event(previous, "on_blur")

if previous != view.tag:

dispatch_event(view.tag, "on_focus")

return None

if name == "blur":

if self.focused_tag == view.tag:

self.focused_tag = None

dispatch_event(view.tag, "on_blur")

return None

if name == "clear":

view.props["value"] = ""

self.selections[view.tag] = (0, 0)

return None

if name == "select_all":

self.selections[view.tag] = (0, len(value))

return None

if name == "set_selection":

start = int(arguments.get("start", 0))

end = int(arguments.get("end", start))

self.selections[view.tag] = (start, end)

return None

def _scroll_view_command(self, view: FakeView, name: str, arguments: Dict[str, Any]) -> Any:

offset = self.scroll_offsets.setdefault(view.tag, {"x": 0.0, "y": 0.0})

if name == "get_scroll_offset":

return dict(offset)

if name == "scroll_to_offset":

if "x" in arguments and arguments["x"] is not None:

offset["x"] = float(arguments["x"])

if "y" in arguments and arguments["y"] is not None:

offset["y"] = float(arguments["y"])

return None

if name == "scroll_to_end":

horizontal = bool(view.props.get("horizontal"))

_, _, width, height = view.frame

if horizontal:

extent = max((c.frame[0] + c.frame[2] for c in view.children), default=0.0)

offset["x"] = max(0.0, extent - width)

else:

extent = max((c.frame[1] + c.frame[3] for c in view.children), default=0.0)

offset["y"] = max(0.0, extent - height)

return None

if name == "scroll_to_top":

offset["x"] = 0.0

offset["y"] = 0.0

return None

def _web_view_command(self, view: FakeView, name: str, arguments: Dict[str, Any]) -> Any:

if name in ("can_go_back", "can_go_forward"):

return False

if name == "get_url":

return view.props.get("url")

if name == "get_title":

return None

if name == "load_url":

url = arguments.get("url")

if isinstance(url, str):

view.props["url"] = url

return None

def request_list(self, tag: int, first: int, *, extent: float = 800.0) -> None:

"""Simulate a native viewport using the shared list request protocol."""

from ..events import dispatch_event

view = self._require(tag, "request_list")

if view.type_name != "VirtualList":

raise TypeError("request_list requires a VirtualList tag")

store = self.list_stores[tag]

keys = store.keys

heights = [store.rows[key].extent for key in keys]

first = max(0, min(first, len(keys) - 1))

last, covered = first, 0.0

while last < len(keys) and covered < extent:

covered += heights[last]

last += 1

offset = sum(heights[:first])

dispatch_event(

tag,

"on_window",

{

"revision": store.revision,

"sticky": next((i for i in range(first, -1, -1) if keys and store.rows[keys[i]].sticky), -1),

"first": first,

"last": last - 1,

"extent": extent,

"range": sum(heights),

"x": offset if view.props.get("horizontal") else 0,

"y": 0 if view.props.get("horizontal") else offset,

)

dispatch_event(

tag,

"on_scroll",

{

"extent": extent,

"range": sum(heights),

"x": offset if view.props.get("horizontal") else 0,

"y": 0 if view.props.get("horizontal") else offset,

)

if keys:

dispatch_event(

tag,

"on_bind_row",

{

"sticky": next((i for i in range(first, -1, -1) if store.rows[keys[i]].sticky), -1),

"key": keys[first],

"index": first,

"revision": store.revision,

"extent": extent,

"width": view.frame[2],

)

def set_animated_property(self, tag: int, prop_name: str, value: Any) -> None:

"""Record an animated property write in ``animated`` without touching ``props``."""

self.animated.append((tag, prop_name, value))

def start_animation(self, tag: int, anim_id: int, prop_name: str, spec: Dict[str, Any]) -> bool:

"""Decline native animation (return ``False``) so animations run through the Python driver."""

return False

def cancel_animation(self, tag: int, anim_id: int) -> Any:

"""Do nothing; the fake never starts native animations."""

return None

# ------------------------------------------------------------------

# Diagnostics

# ------------------------------------------------------------------

def live_view_count(self) -> int:

"""Return how many views are currently registered (created and not yet destroyed)."""

return len(self.views)

def ops_of(self, kind: str) -> List[Any]:

"""Every recorded op tuple whose first element is ``kind``."""

return [op for op in self.ops if op[0] == kind]

def detached_views(self, type_name: Optional[str] = None) -> List[FakeView]:

"""Live views never inserted into a parent (``Portal`` overlays, the root)."""

out = [v for v in self.views.values() if v.parent is None]

if type_name is not None:

out = [v for v in out if v.type_name == type_name]

return out

pythonnative/src/pythonnative/testing/backend.py at main · pythonnative/pythonnative · GitHub

Expand file tree

Breadcrumbs

backend.py

Latest commit

History

Breadcrumbs

backend.py

File metadata and controls