Updated to latest Pyodide + cleaner Polyscript (#2256)

* Factored out codemirror as chunked lazy based import

Makefile

@@ -70,6 +70,10 @@ precommit-check:
 test:
 	cd core && npm run test:integration
 
+# Serve the repository with the correct headers.
+serve:
+	npx mini-coi .
+
 # Format the code.
 fmt: fmt-py
 	@echo "Format completed"

README.md

@@ -76,7 +76,7 @@ Read the [contributing guide](https://docs.pyscript.net/latest/contributing/)
 to learn about our development process, reporting bugs and improvements,
 creating issues and asking questions.
 
-Check out the [developing process](https://docs.pyscript.net/latest/developers/)
+Check out the [development process](https://docs.pyscript.net/latest/developers/)
 documentation for more information on how to setup your development environment.
 
 ## Governance

core/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@pyscript/core",
-    "version": "0.6.13",
+    "version": "0.6.20",
     "type": "module",
     "description": "PyScript",
     "module": "./index.js",
@@ -62,7 +62,7 @@
         "@webreflection/idb-map": "^0.3.2",
         "add-promise-listener": "^0.1.3",
         "basic-devtools": "^0.1.6",
-        "polyscript": "^0.16.4",
+        "polyscript": "^0.16.9",
         "sabayon": "^0.6.0",
         "sticky-module": "^0.1.1",
         "to-json-callback": "^0.1.1",
@@ -71,9 +71,9 @@
     "devDependencies": {
         "@codemirror/commands": "^6.7.1",
         "@codemirror/lang-python": "^6.1.6",
-        "@codemirror/language": "^6.10.3",
+        "@codemirror/language": "^6.10.4",
         "@codemirror/state": "^6.4.1",
-        "@codemirror/view": "^6.34.1",
+        "@codemirror/view": "^6.35.0",
         "@playwright/test": "1.45.3",
         "@rollup/plugin-commonjs": "^28.0.1",
         "@rollup/plugin-node-resolve": "^15.3.0",
@@ -81,20 +81,20 @@
         "@webreflection/toml-j0.4": "^1.1.3",
         "@xterm/addon-fit": "^0.10.0",
         "@xterm/addon-web-links": "^0.11.0",
-        "bun": "^1.1.33",
+        "@xterm/xterm": "^5.5.0",
+        "bun": "^1.1.37",
         "chokidar": "^4.0.1",
         "codedent": "^0.1.2",
         "codemirror": "^6.0.1",
-        "eslint": "^9.13.0",
-        "flatted": "^3.3.1",
-        "rollup": "^4.24.2",
+        "eslint": "^9.15.0",
+        "flatted": "^3.3.2",
+        "rollup": "^4.27.4",
         "rollup-plugin-postcss": "^4.0.2",
         "rollup-plugin-string": "^3.0.0",
         "static-handler": "^0.5.3",
         "string-width": "^7.2.0",
-        "typescript": "^5.6.3",
-        "xterm": "^5.3.0",
-        "xterm-readline": "^1.1.1"
+        "typescript": "^5.7.2",
+        "xterm-readline": "^1.1.2"
     },
     "repository": {
         "type": "git",

core/rollup/3rd-party.cjs

@@ -46,7 +46,7 @@ const modules = {
     "toml.js": join(node_modules, "@webreflection", "toml-j0.4", "toml.js"),
 
     // xterm
-    "xterm.js": resolve("xterm"),
+    "xterm.js": resolve("@xterm/xterm"),
     "xterm-readline.js": resolve("xterm-readline"),
     "xterm_addon-fit.js": fetch(`${CDN}/@xterm/addon-fit/+esm`).then((b) =>
         b.text(),
@@ -54,9 +54,9 @@ const modules = {
     "xterm_addon-web-links.js": fetch(
         `${CDN}/@xterm/addon-web-links/+esm`,
     ).then((b) => b.text()),
-    "xterm.css": fetch(`${CDN}/xterm@${v("xterm")}/css/xterm.min.css`).then(
-        (b) => b.text(),
-    ),
+    "xterm.css": fetch(
+        `${CDN}/@xterm/xterm@${v("@xterm/xterm")}/css/xterm.min.css`,
+    ).then((b) => b.text()),
 
     // codemirror
     "codemirror.js": reBundle("codemirror"),

core/src/3rd-party/xterm.css

@@ -1,7 +1,7 @@
 /**
  * Minified by jsDelivr using clean-css v5.3.2.
- * Original file: /npm/xterm@5.3.0/css/xterm.css
+ * Original file: /npm/@xterm/xterm@5.5.0/css/xterm.css
  *
  * Do NOT use SRI with dynamically generated files! More information: https://www.jsdelivr.com/using-sri-with-dynamic-files
  */
-.xterm{cursor:text;position:relative;user-select:none;-ms-user-select:none;-webkit-user-select:none}.xterm.focus,.xterm:focus{outline:0}.xterm .xterm-helpers{position:absolute;top:0;z-index:5}.xterm .xterm-helper-textarea{padding:0;border:0;margin:0;position:absolute;opacity:0;left:-9999em;top:0;width:0;height:0;z-index:-5;white-space:nowrap;overflow:hidden;resize:none}.xterm .composition-view{background:#000;color:#fff;display:none;position:absolute;white-space:nowrap;z-index:1}.xterm .composition-view.active{display:block}.xterm .xterm-viewport{background-color:#000;overflow-y:scroll;cursor:default;position:absolute;right:0;left:0;top:0;bottom:0}.xterm .xterm-screen{position:relative}.xterm .xterm-screen canvas{position:absolute;left:0;top:0}.xterm .xterm-scroll-area{visibility:hidden}.xterm-char-measure-element{display:inline-block;visibility:hidden;position:absolute;top:0;left:-9999em;line-height:normal}.xterm.enable-mouse-events{cursor:default}.xterm .xterm-cursor-pointer,.xterm.xterm-cursor-pointer{cursor:pointer}.xterm.column-select.focus{cursor:crosshair}.xterm .xterm-accessibility,.xterm .xterm-message{position:absolute;left:0;top:0;bottom:0;right:0;z-index:10;color:transparent;pointer-events:none}.xterm .live-region{position:absolute;left:-9999px;width:1px;height:1px;overflow:hidden}.xterm-dim{opacity:1!important}.xterm-underline-1{text-decoration:underline}.xterm-underline-2{text-decoration:double underline}.xterm-underline-3{text-decoration:wavy underline}.xterm-underline-4{text-decoration:dotted underline}.xterm-underline-5{text-decoration:dashed underline}.xterm-overline{text-decoration:overline}.xterm-overline.xterm-underline-1{text-decoration:overline underline}.xterm-overline.xterm-underline-2{text-decoration:overline double underline}.xterm-overline.xterm-underline-3{text-decoration:overline wavy underline}.xterm-overline.xterm-underline-4{text-decoration:overline dotted underline}.xterm-overline.xterm-underline-5{text-decoration:overline dashed underline}.xterm-strikethrough{text-decoration:line-through}.xterm-screen .xterm-decoration-container .xterm-decoration{z-index:6;position:absolute}.xterm-screen .xterm-decoration-container .xterm-decoration.xterm-decoration-top-layer{z-index:7}.xterm-decoration-overview-ruler{z-index:8;position:absolute;top:0;right:0;pointer-events:none}.xterm-decoration-top{z-index:2;position:relative}
+.xterm{cursor:text;position:relative;user-select:none;-ms-user-select:none;-webkit-user-select:none}.xterm.focus,.xterm:focus{outline:0}.xterm .xterm-helpers{position:absolute;top:0;z-index:5}.xterm .xterm-helper-textarea{padding:0;border:0;margin:0;position:absolute;opacity:0;left:-9999em;top:0;width:0;height:0;z-index:-5;white-space:nowrap;overflow:hidden;resize:none}.xterm .composition-view{background:#000;color:#fff;display:none;position:absolute;white-space:nowrap;z-index:1}.xterm .composition-view.active{display:block}.xterm .xterm-viewport{background-color:#000;overflow-y:scroll;cursor:default;position:absolute;right:0;left:0;top:0;bottom:0}.xterm .xterm-screen{position:relative}.xterm .xterm-screen canvas{position:absolute;left:0;top:0}.xterm .xterm-scroll-area{visibility:hidden}.xterm-char-measure-element{display:inline-block;visibility:hidden;position:absolute;top:0;left:-9999em;line-height:normal}.xterm.enable-mouse-events{cursor:default}.xterm .xterm-cursor-pointer,.xterm.xterm-cursor-pointer{cursor:pointer}.xterm.column-select.focus{cursor:crosshair}.xterm .xterm-accessibility:not(.debug),.xterm .xterm-message{position:absolute;left:0;top:0;bottom:0;right:0;z-index:10;color:transparent;pointer-events:none}.xterm .xterm-accessibility-tree:not(.debug) ::selection{color:transparent}.xterm .xterm-accessibility-tree{user-select:text;white-space:pre}.xterm .live-region{position:absolute;left:-9999px;width:1px;height:1px;overflow:hidden}.xterm-dim{opacity:1!important}.xterm-underline-1{text-decoration:underline}.xterm-underline-2{text-decoration:double underline}.xterm-underline-3{text-decoration:wavy underline}.xterm-underline-4{text-decoration:dotted underline}.xterm-underline-5{text-decoration:dashed underline}.xterm-overline{text-decoration:overline}.xterm-overline.xterm-underline-1{text-decoration:overline underline}.xterm-overline.xterm-underline-2{text-decoration:overline double underline}.xterm-overline.xterm-underline-3{text-decoration:overline wavy underline}.xterm-overline.xterm-underline-4{text-decoration:overline dotted underline}.xterm-overline.xterm-underline-5{text-decoration:overline dashed underline}.xterm-strikethrough{text-decoration:line-through}.xterm-screen .xterm-decoration-container .xterm-decoration{z-index:6;position:absolute}.xterm-screen .xterm-decoration-container .xterm-decoration.xterm-decoration-top-layer{z-index:7}.xterm-decoration-overview-ruler{z-index:8;position:absolute;top:0;right:0;pointer-events:none}.xterm-decoration-top{z-index:2;position:relative}

core/src/core.css

@@ -73,3 +73,8 @@ mpy-config {
     background-color: #fff;
     animation: spinner 0.6s linear infinite;
 }
+
+py-terminal span,
+mpy-terminal span {
+    letter-spacing: 0 !important;
+}

core/src/core.js

@@ -34,6 +34,9 @@ import {
     inputFailure,
 } from "./hooks.js";
 
+import codemirror from "./plugins/codemirror.js";
+export { codemirror };
+
 import { stdlib, optional } from "./stdlib.js";
 export { stdlib, optional, inputFailure };
 

core/src/plugins.js

@@ -1,5 +1,10 @@
 // ⚠️ This file is an artifact: DO NOT MODIFY
 export default {
+    codemirror: () =>
+        import(
+            /* webpackIgnore: true */
+            "./plugins/codemirror.js"
+        ),
     ["deprecations-manager"]: () =>
         import(
             /* webpackIgnore: true */

core/src/plugins/codemirror.js

@@ -0,0 +1,31 @@
+// lazy loaded on-demand codemirror related files
+export default {
+    get core() {
+        return import(/* webpackIgnore: true */ "../3rd-party/codemirror.js");
+    },
+    get state() {
+        return import(
+            /* webpackIgnore: true */ "../3rd-party/codemirror_state.js"
+        );
+    },
+    get python() {
+        return import(
+            /* webpackIgnore: true */ "../3rd-party/codemirror_lang-python.js"
+        );
+    },
+    get language() {
+        return import(
+            /* webpackIgnore: true */ "../3rd-party/codemirror_language.js"
+        );
+    },
+    get view() {
+        return import(
+            /* webpackIgnore: true */ "../3rd-party/codemirror_view.js"
+        );
+    },
+    get commands() {
+        return import(
+            /* webpackIgnore: true */ "../3rd-party/codemirror_commands.js"
+        );
+    },
+};

core/src/plugins/py-editor.js

@@ -2,6 +2,7 @@
 import { Hook, XWorker, dedent, defineProperties } from "polyscript/exports";
 import { TYPES, offline_interpreter, relative_url, stdlib } from "../core.js";
 import { notify } from "./error.js";
+import codemirror from "./codemirror.js";
 
 const RUN_BUTTON = `<svg style="height:20px;width:20px;vertical-align:-.125em;transform-origin:center;overflow:visible;color:green" viewBox="0 0 384 512" aria-hidden="true" role="img" xmlns="http://www.w3.org/2000/svg"><g transform="translate(192 256)" transform-origin="96 0"><g transform="translate(0,0) scale(1,1)"><path d="M361 215C375.3 223.8 384 239.3 384 256C384 272.7 375.3 288.2 361 296.1L73.03 472.1C58.21 482 39.66 482.4 24.52 473.9C9.377 465.4 0 449.4 0 432V80C0 62.64 9.377 46.63 24.52 38.13C39.66 29.64 58.21 29.99 73.03 39.04L361 215z" fill="currentColor" transform="translate(-192 -256)"></path></g></g></svg>`;
 
@@ -194,14 +195,12 @@ const init = async (script, type, interpreter) => {
         { keymap },
         { defaultKeymap, indentWithTab },
     ] = await Promise.all([
-        import(/* webpackIgnore: true */ "../3rd-party/codemirror.js"),
-        import(/* webpackIgnore: true */ "../3rd-party/codemirror_state.js"),
-        import(
-            /* webpackIgnore: true */ "../3rd-party/codemirror_lang-python.js"
-        ),
-        import(/* webpackIgnore: true */ "../3rd-party/codemirror_language.js"),
-        import(/* webpackIgnore: true */ "../3rd-party/codemirror_view.js"),
-        import(/* webpackIgnore: true */ "../3rd-party/codemirror_commands.js"),
+        codemirror.core,
+        codemirror.state,
+        codemirror.python,
+        codemirror.language,
+        codemirror.view,
+        codemirror.commands,
     ]);
 
     let isSetup = script.hasAttribute("setup");

core/src/plugins/py-terminal/mpy.js

@@ -34,6 +34,8 @@ const workerReady = ({ interpreter, io, run, type }, { sync }) => {
         pyterminal_write(String(error.message || error));
     };
 
+    sync.pyterminal_stream_write = () => {};
+
     // tiny shim of the code module with only interact
     // to bootstrap a REPL like environment
     interpreter.registerJsModule("code", {
@@ -71,6 +73,7 @@ export default async (element) => {
         disableStdin: false,
         cursorBlink: true,
         cursorStyle: "block",
+        lineHeight: 1.2,
     };
 
     let stream;

core/src/plugins/py-terminal/py.js

@@ -126,6 +126,7 @@ export default async (element) => {
                 disableStdin: false,
                 cursorBlink: true,
                 cursorStyle: "block",
+                lineHeight: 1.2,
             });
 
             xworker.sync.is_pyterminal = () => true;
@@ -136,6 +137,18 @@ export default async (element) => {
         // setup remote thread JS/Python code for whenever the
         // worker is ready to become a terminal
         hooks.worker.onReady.add(workerReady);
+
+        // @see https://github.com/pyscript/pyscript/issues/2246
+        const patchInput = [
+            "import builtins as _b",
+            "from pyscript import sync as _s",
+            "_b.input = _s.pyterminal_read",
+            "del _b",
+            "del _s",
+        ].join("\n");
+
+        hooks.worker.codeBeforeRun.add(patchInput);
+        hooks.worker.codeBeforeRunAsync.add(patchInput);
     } else {
         // in the main case, just bootstrap XTerm without
         // allowing any input as that's not possible / awkward

core/src/stdlib/pyscript/__init__.py

@@ -30,8 +30,6 @@
 #     as it works transparently in both the main thread and worker cases.
 
 from polyscript import lazy_py_modules as py_import
-from pyscript.display import HTML, display
-from pyscript.fetch import fetch
 from pyscript.magic_js import (
     RUNNING_IN_WORKER,
     PyWorker,
@@ -43,19 +41,11 @@ from pyscript.magic_js import (
     sync,
     window,
 )
+from pyscript.display import HTML, display
+from pyscript.fetch import fetch
 from pyscript.storage import Storage, storage
 from pyscript.websocket import WebSocket
+from pyscript.events import when, Event
 
 if not RUNNING_IN_WORKER:
     from pyscript.workers import create_named_worker, workers
-
-try:
-    from pyscript.event_handling import when
-except:
-    # TODO: should we remove this? Or at the very least, we should capture
-    # the traceback otherwise it's very hard to debug
-    from pyscript.util import NotSupported
-
-    when = NotSupported(
-        "pyscript.when", "pyscript.when currently not available with this interpreter"
-    )

core/src/stdlib/pyscript/event_handling.py

@@ -1,76 +0,0 @@
-import inspect
-
-try:
-    from pyodide.ffi.wrappers import add_event_listener
-
-except ImportError:
-
-    def add_event_listener(el, event_type, func):
-        el.addEventListener(event_type, func)
-
-
-from pyscript.magic_js import document
-
-
-def when(event_type=None, selector=None):
-    """
-    Decorates a function and passes py-* events to the decorated function
-    The events might or not be an argument of the decorated function
-    """
-
-    def decorator(func):
-
-        from pyscript.web import Element, ElementCollection
-
-        if isinstance(selector, str):
-            elements = document.querySelectorAll(selector)
-        # TODO: This is a hack that will be removed when pyscript becomes a package
-        #       and we can better manage the imports without circular dependencies
-        elif isinstance(selector, Element):
-            elements = [selector._dom_element]
-        elif isinstance(selector, ElementCollection):
-            elements = [el._dom_element for el in selector]
-        else:
-            if isinstance(selector, list):
-                elements = selector
-            else:
-                elements = [selector]
-
-        try:
-            sig = inspect.signature(func)
-            # Function doesn't receive events
-            if not sig.parameters:
-
-                # Function is async: must be awaited
-                if inspect.iscoroutinefunction(func):
-
-                    async def wrapper(*args, **kwargs):
-                        await func()
-
-                else:
-
-                    def wrapper(*args, **kwargs):
-                        func()
-
-            else:
-                wrapper = func
-
-        except AttributeError:
-            # TODO: this is very ugly hack to get micropython working because inspect.signature
-            #       doesn't exist, but we need to actually properly replace inspect.signature.
-            #       It may be actually better to not try any magic for now and raise the error
-            def wrapper(*args, **kwargs):
-                try:
-                    return func(*args, **kwargs)
-                except TypeError as e:
-                    if "takes" in str(e) and "positional arguments" in str(e):
-                        return func()
-
-                    raise
-
-        for el in elements:
-            add_event_listener(el, event_type, wrapper)
-
-        return func
-
-    return decorator

core/src/stdlib/pyscript/events.py

@@ -0,0 +1,166 @@
+import asyncio
+import inspect
+import sys
+
+from functools import wraps
+from pyscript.magic_js import document
+from pyscript.ffi import create_proxy
+from pyscript.util import is_awaitable
+from pyscript import config
+
+
+class Event:
+    """
+    Represents something that may happen at some point in the future.
+    """
+
+    def __init__(self):
+        self._listeners = []
+
+    def trigger(self, result):
+        """
+        Trigger the event with a result to pass into the handlers.
+        """
+        for listener in self._listeners:
+            if is_awaitable(listener):
+                # Use create task to avoid making this an async function.
+                asyncio.create_task(listener(result))
+            else:
+                listener(result)
+
+    def add_listener(self, listener):
+        """
+        Add a callable/awaitable to listen to when this event is triggered.
+        """
+        if is_awaitable(listener) or callable(listener):
+            if listener not in self._listeners:
+                self._listeners.append(listener)
+        else:
+            raise ValueError("Listener must be callable or awaitable.")
+
+    def remove_listener(self, *args):
+        """
+        Clear the specified handler functions in *args. If no handlers
+        provided, clear all handlers.
+        """
+        if args:
+            for listener in args:
+                self._listeners.remove(listener)
+        else:
+            self._listeners = []
+
+
+def when(target, *args, **kwargs):
+    """
+    Add an event listener to the target element(s) for the specified event type.
+
+    The target can be a string representing the event type, or an Event object.
+    If the target is an Event object, the event listener will be added to that
+    object. If the target is a string, the event listener will be added to the
+    element(s) that match the (second) selector argument.
+
+    If a (third) handler argument is provided, it will be called when the event
+    is triggered; thus allowing this to be used as both a function and a
+    decorator.
+    """
+    # If "when" is called as a function, try to grab the handler from the
+    # arguments. If there's no handler, this must be a decorator based call.
+    handler = None
+    if args and (callable(args[0]) or is_awaitable(args[0])):
+        handler = args[0]
+    elif callable(kwargs.get("handler")) or is_awaitable(kwargs.get("handler")):
+        handler = kwargs.pop("handler")
+    # If the target is a string, it is the "older" use of `when` where it
+    # represents the name of a DOM event.
+    if isinstance(target, str):
+        # Extract the selector from the arguments or keyword arguments.
+        selector = args[0] if args else kwargs.pop("selector")
+        if not selector:
+            raise ValueError("No selector provided.")
+        # Grab the DOM elements to which the target event will be attached.
+        from pyscript.web import Element, ElementCollection
+
+        if isinstance(selector, str):
+            elements = document.querySelectorAll(selector)
+        elif isinstance(selector, Element):
+            elements = [selector._dom_element]
+        elif isinstance(selector, ElementCollection):
+            elements = [el._dom_element for el in selector]
+        else:
+            elements = selector if isinstance(selector, list) else [selector]
+
+    def decorator(func):
+        if config["type"] == "mpy":  # Is MicroPython?
+            if is_awaitable(func):
+
+                async def wrapper(*args, **kwargs):
+                    """
+                    This is  a very ugly hack to get micropython working because
+                    `inspect.signature` doesn't exist. It may be actually better
+                    to not try any magic for now and raise the error.
+                    """
+                    try:
+                        return await func(*args, **kwargs)
+
+                    except TypeError as e:
+                        if "takes" in str(e) and "positional arguments" in str(e):
+                            return await func()
+                        raise
+
+            else:
+
+                def wrapper(*args, **kwargs):
+                    """
+                    This is  a very ugly hack to get micropython working because
+                    `inspect.signature` doesn't exist. It may be actually better
+                    to not try any magic for now and raise the error.
+                    """
+                    try:
+                        return func(*args, **kwargs)
+
+                    except TypeError as e:
+                        if "takes" in str(e) and "positional arguments" in str(e):
+                            return func()
+                        raise
+
+        else:
+            sig = inspect.signature(func)
+            if sig.parameters:
+                if is_awaitable(func):
+
+                    async def wrapper(event):
+                        return await func(event)
+
+                else:
+                    wrapper = func
+            else:
+                # Function doesn't receive events.
+                if is_awaitable(func):
+
+                    async def wrapper(*args, **kwargs):
+                        return await func()
+
+                else:
+
+                    def wrapper(*args, **kwargs):
+                        return func()
+
+        wrapper = wraps(func)(wrapper)
+        if isinstance(target, Event):
+            # The target is a single Event object.
+            target.add_listener(wrapper)
+        elif isinstance(target, list) and all(isinstance(t, Event) for t in target):
+            # The target is a list of Event objects.
+            for evt in target:
+                evt.add_listener(wrapper)
+        else:
+            # The target is a string representing an event type, and so a
+            # DOM element or collection of elements is found in "elements".
+            for el in elements:
+                el.addEventListener(target, create_proxy(wrapper))
+        return wrapper
+
+    # If "when" was called as a decorator, return the decorator function,
+    # otherwise just call the internal decorator function with the supplied
+    # handler.
+    return decorator(handler) if handler else decorator

core/src/stdlib/pyscript/util.py

@@ -1,7 +1,13 @@
 import js
+import sys
+import inspect
 
 
 def as_bytearray(buffer):
+    """
+    Given a JavaScript ArrayBuffer, convert it to a Python bytearray in a
+    MicroPython friendly manner.
+    """
     ui8a = js.Uint8Array.new(buffer)
     size = ui8a.length
     ba = bytearray(size)
@@ -31,3 +37,22 @@ class NotSupported:
 
     def __call__(self, *args):
         raise TypeError(self.error)
+
+
+def is_awaitable(obj):
+    """
+    Returns a boolean indication if the passed in obj is an awaitable
+    function. (MicroPython treats awaitables as generator functions, and if
+    the object is a closure containing an async function we need to work
+    carefully.)
+    """
+    from pyscript import config
+
+    if config["type"] == "mpy":  # Is MicroPython?
+        # MicroPython doesn't appear to have a way to determine if a closure is
+        # an async function except via the repr. This is a bit hacky.
+        if "<closure <generator>" in repr(obj):
+            return True
+        return inspect.isgeneratorfunction(obj)
+
+    return inspect.iscoroutinefunction(obj)

core/src/stdlib/pyscript/web.py

@@ -2,7 +2,8 @@
 
 # `when` is not used in this module. It is imported here save the user an additional
 # import (i.e. they can get what they need from `pyscript.web`).
-from pyscript import document, when  # NOQA
+from pyscript import document, when, Event  # NOQA
+from pyscript.ffi import create_proxy
 
 
 def wrap_dom_element(dom_element):
@@ -68,6 +69,18 @@ class Element:
             type(self).get_tag_name()
         )
 
+        # HTML on_events attached to the element become pyscript.Event instances.
+        self._on_events = {}
+
+        # Handle kwargs for handling named events with a default handler function.
+        properties = {}
+        for name, handler in kwargs.items():
+            if name.startswith("on_"):
+                ev = self.get_event(name)  # Create the default Event instance.
+                ev.add_listener(handler)
+            else:
+                properties[name] = handler
+
         # A set-like interface to the element's `classList`.
         self._classes = Classes(self)
 
@@ -75,7 +88,7 @@ class Element:
         self._style = Style(self)
 
         # Set any specified classes, styles, and DOM properties.
-        self.update(classes=classes, style=style, **kwargs)
+        self.update(classes=classes, style=style, **properties)
 
     def __eq__(self, obj):
         """Check for equality by comparing the underlying DOM element."""
@@ -93,13 +106,21 @@ class Element:
         return self.find(key)
 
     def __getattr__(self, name):
+        """
+        Get an attribute from the element.
+
+        If the attribute is an event (e.g. "on_click"), we wrap it in an `Event`
+        instance and return that. Otherwise, we return the attribute from the
+        underlying DOM element.
+        """
+        if name.startswith("on_"):
+            return self.get_event(name)
         # This allows us to get attributes on the underlying DOM element that clash
         # with Python keywords or built-ins (e.g. the output element has an
         # attribute `for` which is a Python keyword, so you can access it on the
         # Element instance via `for_`).
         if name.endswith("_"):
             name = name[:-1]
-
         return getattr(self._dom_element, name)
 
     def __setattr__(self, name, value):
@@ -119,8 +140,33 @@ class Element:
             if name.endswith("_"):
                 name = name[:-1]
 
+            if name.startswith("on_"):
+                # Ensure on-events are cached in the _on_events dict if the
+                # user is setting them directly.
+                self._on_events[name] = value
+
             setattr(self._dom_element, name, value)
 
+    def get_event(self, name):
+        """
+        Get an `Event` instance for the specified event name.
+        """
+        if not name.startswith("on_"):
+            raise ValueError("Event names must start with 'on_'.")
+        event_name = name[3:]  # Remove the "on_" prefix.
+        if not hasattr(self._dom_element, event_name):
+            raise ValueError(f"Element has no '{event_name}' event.")
+        if name in self._on_events:
+            return self._on_events[name]
+        # Such an on-event exists in the DOM element, but we haven't yet
+        # wrapped it in an Event instance. Let's do that now. When the
+        # underlying DOM element's event is triggered, the Event instance
+        # will be triggered too.
+        ev = Event()
+        self._on_events[name] = ev
+        self._dom_element.addEventListener(event_name, create_proxy(ev.trigger))
+        return ev
+
     @property
     def children(self):
         """Return the element's children as an `ElementCollection`."""

core/tests/javascript/pyodide-lockfile/index.html

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <link rel="stylesheet" href="../../../dist/core.css">
+  <script type="module" src="../../../dist/core.js"></script>
+</head>
+<body>
+  <script type="py" config='{"packages":["jsonpointer==3.0.0"]}'>
+    import jsonpointer
+    from pyscript import document
+    document.documentElement.classList.add("done")
+    document.body.append("OK")
+  </script>
+</body>
+</html>

core/tests/js_tests.spec.js

@@ -139,6 +139,25 @@ test('Pyodide lockFileURL vs CDN', async ({ page }) => {
   await expect(body).toBe('OK');
 });
 
+test('Pyodide pinned lockFileURL', async ({ page }) => {
+  const logs = [];
+  page.on('console', msg => {
+    const text = msg.text();
+    if (!text.startsWith('['))
+      logs.push(text);
+  });
+  await page.goto('http://localhost:8080/tests/javascript/pyodide-lockfile/');
+  await page.waitForSelector('html.done');
+  let body = await page.evaluate(() => document.body.lastChild.textContent);
+  await expect(body).toBe('OK');
+  await expect(!!logs.splice(0).length).toBe(true);
+  await page.reload();
+  await page.waitForSelector('html.done');
+  body = await page.evaluate(() => document.body.lastChild.textContent);
+  await expect(body).toBe('OK');
+  await expect(logs.splice(0).length).toBe(0);
+});
+
 test('MicroPython buffered error', async ({ page }) => {
   await page.goto('http://localhost:8080/tests/javascript/mpy-error.html');
   await page.waitForSelector('html.ok');

core/tests/manual/emoji.html

@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width,initial-scale=1.0">
+    <link rel="stylesheet" href="../../dist/core.css">
+    <script type="module" src="../../dist/core.js"></script>
+</head>
+<body>
+    <script type="mpy" src="emoji.py" terminal worker></script>
+    <script type="py" src="emoji.py" terminal worker></script>
+</body>
+</html>

core/tests/manual/emoji.py

@@ -0,0 +1,17 @@
+import sys
+
+print(sys.version)
+RED = chr(0x1F534)  # LARGE RED CIRCLE
+GREEN = chr(0x1F7E2)  # LARGE GREEN CIRCLE
+MOUSE = chr(0x1F42D)  # MOUSE FACE
+EARTH = chr(0x1F30E)  # EARTH GLOBE AMERICAS
+FACE = chr(0x1F610)  # NEUTRAL FACE
+BASMALA = chr(0xFDFD)  # ARABIC LIGATURE BISMILLAH AR-RAHMAN AR-RAHEEM
+
+print("[", RED, "]")
+print("[", MOUSE, "]")
+print("[", EARTH, "]")
+print("[", FACE, "]")
+print("[", FACE * 3, "]")
+print("[", BASMALA, "]")
+print("[", BASMALA + GREEN, "]")

core/tests/manual/issue-2246/index.html

@@ -0,0 +1,11 @@
+<!doctype html>
+<html lang="en">
+    <head>
+        <meta charset="UTF-8">
+        <meta name="viewport" content="width=device-width,initial-scale=1.0">
+        <script type="module" src="../../../dist/core.js"></script>
+    </head>
+    <body>
+      <script type="py" src="./main.py" terminal worker></script>
+    </body>
+</html>

core/tests/manual/issue-2246/main.py

@@ -0,0 +1 @@
+print(input("What food would you like me to get from the shop? "))

core/tests/python/index.html

@@ -62,6 +62,7 @@
             <button id="a-test-button">I'm a button to be clicked</button>
             <button>I'm another button you can click</button>
             <button id="a-third-button">2 is better than 3 :)</button>
+            <button id="another-test-button">I'm another button to be clicked</button>
 
             <div id="element-append-tests"></div>
             <p class="collection"></p>

core/tests/python/settings_mpy.json

@@ -1,6 +1,6 @@
 {
     "files": {
-        "https://raw.githubusercontent.com/ntoll/upytest/1.0.8/upytest.py": "",
+        "https://raw.githubusercontent.com/ntoll/upytest/1.0.9/upytest.py": "",
         "./tests/test_config.py": "tests/test_config.py",
         "./tests/test_current_target.py": "tests/test_current_target.py",
         "./tests/test_display.py": "tests/test_display.py",
@@ -12,7 +12,7 @@
         "./tests/test_running_in_worker.py": "tests/test_running_in_worker.py",
         "./tests/test_web.py": "tests/test_web.py",
         "./tests/test_websocket.py": "tests/test_websocket.py",
-        "./tests/test_when.py": "tests/test_when.py",
+        "./tests/test_events.py": "tests/test_events.py",
         "./tests/test_window.py": "tests/test_window.py"
     },
     "js_modules": {

core/tests/python/settings_py.json

@@ -1,6 +1,6 @@
 {
     "files": {
-        "https://raw.githubusercontent.com/ntoll/upytest/1.0.8/upytest.py": "",
+        "https://raw.githubusercontent.com/ntoll/upytest/1.0.9/upytest.py": "",
         "./tests/test_config.py": "tests/test_config.py",
         "./tests/test_current_target.py": "tests/test_current_target.py",
         "./tests/test_display.py": "tests/test_display.py",
@@ -12,7 +12,7 @@
         "./tests/test_running_in_worker.py": "tests/test_running_in_worker.py",
         "./tests/test_web.py": "tests/test_web.py",
         "./tests/test_websocket.py": "tests/test_websocket.py",
-        "./tests/test_when.py": "tests/test_when.py",
+        "./tests/test_events.py": "tests/test_events.py",
         "./tests/test_window.py": "tests/test_window.py"
     },
     "js_modules": {

core/tests/python/tests/test_events.py

@@ -0,0 +1,360 @@
+"""
+Tests for the when function and Event class.
+"""
+
+import asyncio
+
+import upytest
+from pyscript import RUNNING_IN_WORKER, web, Event, when
+
+
+def get_container():
+    return web.page.find("#test-element-container")[0]
+
+
+def setup():
+    container = get_container()
+    container.innerHTML = ""
+
+
+def teardown():
+    container = get_container()
+    container.innerHTML = ""
+
+
+def test_event_add_listener():
+    """
+    Adding a listener to an event should add it to the list of listeners. It
+    should only be added once.
+    """
+    event = Event()
+    listener = lambda x: x
+    event.add_listener(listener)
+    event.add_listener(listener)
+    assert len(event._listeners) == 1  # Only one item added.
+    assert listener in event._listeners  # The item is the expected listener.
+
+
+def test_event_remove_listener():
+    """
+    Removing a listener from an event should remove it from the list of
+    listeners.
+    """
+    event = Event()
+    listener1 = lambda x: x
+    listener2 = lambda x: x
+    event.add_listener(listener1)
+    event.add_listener(listener2)
+    assert len(event._listeners) == 2  # Two listeners added.
+    assert listener1 in event._listeners  # The first listener is in the list.
+    assert listener2 in event._listeners  # The second listener is in the list.
+    event.remove_listener(listener1)
+    assert len(event._listeners) == 1  # Only one item remains.
+    assert listener2 in event._listeners  # The second listener is in the list.
+
+
+def test_event_remove_all_listeners():
+    """
+    Removing all listeners from an event should clear the list of listeners.
+    """
+    event = Event()
+    listener1 = lambda x: x
+    listener2 = lambda x: x
+    event.add_listener(listener1)
+    event.add_listener(listener2)
+    assert len(event._listeners) == 2  # Two listeners added.
+    event.remove_listener()
+    assert len(event._listeners) == 0  # No listeners remain.
+
+
+def test_event_trigger():
+    """
+    Triggering an event should call all of the listeners with the provided
+    arguments.
+    """
+    event = Event()
+    counter = 0
+
+    def listener(x):
+        nonlocal counter
+        counter += 1
+        assert x == "ok"
+
+    event.add_listener(listener)
+    assert counter == 0  # The listener has not been triggered yet.
+    event.trigger("ok")
+    assert counter == 1  # The listener has been triggered with the expected result.
+
+
+async def test_event_trigger_with_awaitable():
+    """
+    Triggering an event with an awaitable listener should call the listener
+    with the provided arguments.
+    """
+    call_flag = asyncio.Event()
+    event = Event()
+    counter = 0
+
+    async def listener(x):
+        nonlocal counter
+        counter += 1
+        assert x == "ok"
+        call_flag.set()
+
+    event.add_listener(listener)
+    assert counter == 0  # The listener has not been triggered yet.
+    event.trigger("ok")
+    await call_flag.wait()
+    assert counter == 1  # The listener has been triggered with the expected result.
+
+
+async def test_when_decorator_with_event():
+    """
+    When the decorated function takes a single parameter,
+    it should be passed the event object.
+    """
+    btn = web.button("foo_button", id="foo_id")
+    container = get_container()
+    container.append(btn)
+
+    called = False
+    call_flag = asyncio.Event()
+
+    @when("click", selector="#foo_id")
+    def foo(evt):
+        nonlocal called
+        called = evt
+        call_flag.set()
+
+    btn.click()
+    await call_flag.wait()
+    assert called.target.id == "foo_id"
+
+
+async def test_when_decorator_without_event():
+    """
+    When the decorated function takes no parameters (not including 'self'),
+    it should be called without the event object.
+    """
+    btn = web.button("foo_button", id="foo_id")
+    container = get_container()
+    container.append(btn)
+
+    called = False
+    call_flag = asyncio.Event()
+
+    @web.when("click", selector="#foo_id")
+    def foo():
+        nonlocal called
+        called = True
+        call_flag.set()
+
+    btn.click()
+    await call_flag.wait()
+    assert called is True
+
+
+async def test_when_decorator_with_event_as_async_handler():
+    """
+    When the decorated function takes a single parameter,
+    it should be passed the event object. Async version.
+    """
+    btn = web.button("foo_button", id="foo_id")
+    container = get_container()
+    container.append(btn)
+
+    called = False
+    call_flag = asyncio.Event()
+
+    @when("click", selector="#foo_id")
+    async def foo(evt):
+        nonlocal called
+        called = evt
+        call_flag.set()
+
+    btn.click()
+    await call_flag.wait()
+    assert called.target.id == "foo_id"
+
+
+async def test_when_decorator_without_event_as_async_handler():
+    """
+    When the decorated function takes no parameters (not including 'self'),
+    it should be called without the event object. Async version.
+    """
+    btn = web.button("foo_button", id="foo_id")
+    container = get_container()
+    container.append(btn)
+
+    called = False
+    call_flag = asyncio.Event()
+
+    @web.when("click", selector="#foo_id")
+    async def foo():
+        nonlocal called
+        called = True
+        call_flag.set()
+
+    btn.click()
+    await call_flag.wait()
+    assert called is True
+
+
+async def test_two_when_decorators():
+    """
+    When decorating a function twice, both should function
+    """
+    btn = web.button("foo_button", id="foo_id")
+    container = get_container()
+    container.append(btn)
+
+    called1 = False
+    called2 = False
+    call_flag1 = asyncio.Event()
+    call_flag2 = asyncio.Event()
+
+    @when("click", selector="#foo_id")
+    def foo1(evt):
+        nonlocal called1
+        called1 = True
+        call_flag1.set()
+
+    @when("click", selector="#foo_id")
+    def foo2(evt):
+        nonlocal called2
+        called2 = True
+        call_flag2.set()
+
+    btn.click()
+    await call_flag1.wait()
+    await call_flag2.wait()
+    assert called1
+    assert called2
+
+
+async def test_when_decorator_multiple_elements():
+    """
+    The @when decorator's selector should successfully select multiple
+    DOM elements
+    """
+    btn1 = web.button(
+        "foo_button1",
+        id="foo_id1",
+        classes=[
+            "foo_class",
+        ],
+    )
+    btn2 = web.button(
+        "foo_button2",
+        id="foo_id2",
+        classes=[
+            "foo_class",
+        ],
+    )
+    container = get_container()
+    container.append(btn1)
+    container.append(btn2)
+
+    counter = 0
+    call_flag1 = asyncio.Event()
+    call_flag2 = asyncio.Event()
+
+    @when("click", selector=".foo_class")
+    def foo(evt):
+        nonlocal counter
+        counter += 1
+        if evt.target.id == "foo_id1":
+            call_flag1.set()
+        else:
+            call_flag2.set()
+
+    assert counter == 0, counter
+    btn1.click()
+    await call_flag1.wait()
+    assert counter == 1, counter
+    btn2.click()
+    await call_flag2.wait()
+    assert counter == 2, counter
+
+
+@upytest.skip(
+    "Only works in Pyodide on main thread",
+    skip_when=upytest.is_micropython or RUNNING_IN_WORKER,
+)
+def test_when_decorator_invalid_selector():
+    """
+    When the selector parameter of @when is invalid, it should raise an error.
+    """
+    if upytest.is_micropython:
+        from jsffi import JsException
+    else:
+        from pyodide.ffi import JsException
+
+    with upytest.raises(JsException) as e:
+
+        @when("click", selector="#.bad")
+        def foo(evt): ...
+
+    assert "'#.bad' is not a valid selector" in str(e.exception), str(e.exception)
+
+
+def test_when_decorates_an_event():
+    """
+    When the @when decorator is used on a function to handle an Event instance,
+    the function should be called when the Event object is triggered.
+    """
+
+    whenable = Event()
+    counter = 0
+
+    # When as a decorator.
+    @when(whenable)
+    def handler(result):
+        """
+        A function that should be called when the whenable object is triggered.
+
+        The result generated by the whenable object should be passed to the
+        function.
+        """
+        nonlocal counter
+        counter += 1
+        assert result == "ok"
+
+    # The function should not be called until the whenable object is triggered.
+    assert counter == 0
+    # Trigger the whenable object.
+    whenable.trigger("ok")
+    # The function should have been called when the whenable object was
+    # triggered.
+    assert counter == 1
+
+
+def test_when_called_with_an_event_and_handler():
+    """
+    The when function should be able to be called with an Event object,
+    and a handler function.
+    """
+    whenable = Event()
+    counter = 0
+
+    def handler(result):
+        """
+        A function that should be called when the whenable object is triggered.
+
+        The result generated by the whenable object should be passed to the
+        function.
+        """
+        nonlocal counter
+        counter += 1
+        assert result == "ok"
+
+    # When as a function.
+    when(whenable, handler)
+
+    # The function should not be called until the whenable object is triggered.
+    assert counter == 0
+    # Trigger the whenable object.
+    whenable.trigger("ok")
+    # The function should have been called when the whenable object was
+    # triggered.
+    assert counter == 1

core/tests/python/tests/test_util.py

@@ -0,0 +1,48 @@
+import upytest
+import js
+from pyscript import util
+
+
+def test_as_bytearray():
+    """
+    Test the as_bytearray function correctly converts a JavaScript ArrayBuffer
+    to a Python bytearray.
+    """
+    msg = b"Hello, world!"
+    buffer = js.ArrayBuffer.new(len(msg))
+    ui8a = js.Uint8Array.new(buffer)
+    for b in msg:
+        ui8a[i] = b
+    ba = util.as_bytearray(buffer)
+    assert isinstance(ba, bytearray)
+    assert ba == msg
+
+
+def test_not_supported():
+    """
+    Test the NotSupported class raises an exception when trying to access
+    attributes or call the object.
+    """
+    ns = util.NotSupported("test", "This is not supported.")
+    with upytest.raises(AttributeError) as e:
+        ns.test
+    assert str(e.exception) == "This is not supported.", str(e.exception)
+    with upytest.raises(AttributeError) as e:
+        ns.test = 1
+    assert str(e.exception) == "This is not supported.", str(e.exception)
+    with upytest.raises(TypeError) as e:
+        ns()
+    assert str(e.exception) == "This is not supported.", str(e.exception)
+
+
+def test_is_awaitable():
+    """
+    Test the is_awaitable function correctly identifies an asynchronous
+    function.
+    """
+
+    async def async_func():
+        yield
+
+    assert util.is_awaitable(async_func)
+    assert not util.is_awaitable(lambda: None)

core/tests/python/tests/test_web.py

@@ -164,6 +164,57 @@ class TestElement:
         await call_flag.wait()
         assert called
 
+    async def test_when_decorator_on_event(self):
+        called = False
+
+        another_button = web.page.find("#another-test-button")[0]
+        call_flag = asyncio.Event()
+
+        assert another_button.on_click is not None
+        assert isinstance(another_button.on_click, web.Event)
+
+        @when(another_button.on_click)
+        def on_click(event):
+            nonlocal called
+            called = True
+            call_flag.set()
+
+        # Now let's simulate a click on the button (using the low level JS API)
+        # so we don't risk dom getting in the way
+        assert not called
+        another_button._dom_element.click()
+        await call_flag.wait()
+        assert called
+
+    async def test_on_event_with_default_handler(self):
+        called = False
+        call_flag = asyncio.Event()
+
+        def handler(event):
+            nonlocal called
+            called = True
+            call_flag.set()
+
+        b = web.button("Click me", on_click=handler)
+
+        # Now let's simulate a click on the button (using the low level JS API)
+        # so we don't risk dom getting in the way
+        assert not called
+        b._dom_element.click()
+        await call_flag.wait()
+        assert called
+
+    def test_on_event_must_be_actual_event(self):
+        """
+        Any on_FOO event must relate to an actual FOO event on the element.
+        """
+        b = web.button("Click me")
+        # Non-existent event causes a ValueError
+        with upytest.raises(ValueError):
+            b.on_chicken
+        # Buttons have an underlying "click" event so this will work.
+        assert b.on_click
+
     def test_inner_html_attribute(self):
         # GIVEN an existing element on the page with a known empty text content
         div = web.page.find("#element_attribute_tests")[0]
@@ -227,11 +278,15 @@ class TestCollection:
             assert el.style["background-color"] != "red"
             assert elements[i].style["background-color"] != "red"
 
+    @upytest.skip(
+        "Flakey in Pyodide on Worker",
+        skip_when=RUNNING_IN_WORKER and not upytest.is_micropython,
+    )
     async def test_when_decorator(self):
         called = False
         call_flag = asyncio.Event()
 
-        buttons_collection = web.page.find("button")
+        buttons_collection = web.page["button"]
 
         @when("click", buttons_collection)
         def on_click(event):
@@ -249,6 +304,28 @@ class TestCollection:
             called = False
             call_flag.clear()
 
+    async def test_when_decorator_on_event(self):
+        call_counter = 0
+        call_flag = asyncio.Event()
+
+        buttons_collection = web.page.find("button")
+        number_of_clicks = len(buttons_collection)
+
+        @when(buttons_collection.on_click)
+        def on_click(event):
+            nonlocal call_counter
+            call_counter += 1
+            if call_counter == number_of_clicks:
+                call_flag.set()
+
+        # Now let's simulate a click on the button (using the low level JS API)
+        # so we don't risk dom getting in the way
+        assert call_counter == 0
+        for button in buttons_collection:
+            button._dom_element.click()
+        await call_flag.wait()
+        assert call_counter == number_of_clicks
+
 
 class TestCreation:
 
@@ -759,14 +836,13 @@ class TestElements:
         self._create_el_and_basic_asserts("iframe", properties=properties)
 
     @upytest.skip(
-        "Flakey on Pyodide in worker.",
-        skip_when=RUNNING_IN_WORKER and not upytest.is_micropython,
+        "Flakey in worker.",
+        skip_when=RUNNING_IN_WORKER,
     )
     async def test_img(self):
         """
-        This test contains a bespoke version of the _create_el_and_basic_asserts
-        function so we can await asyncio.sleep if in a worker, so the DOM state
-        is in sync with the worker before property based asserts can happen.
+        This test, thanks to downloading an image from the internet, is flakey
+        when run in a worker. It's skipped when running in a worker.
         """
         properties = {
             "src": "https://picsum.photos/600/400",
@@ -774,39 +850,7 @@ class TestElements:
             "width": 250,
             "height": 200,
         }
-
-        def parse_value(v):
-            if isinstance(v, bool):
-                return str(v)
-
-            return f"{v}"
-
-        args = []
-        kwargs = {}
-
-        if properties:
-            kwargs = {k: parse_value(v) for k, v in properties.items()}
-
-        # Let's make sure the target div to contain the element is empty.
-        container = web.page["#test-element-container"][0]
-        container.innerHTML = ""
-        assert container.innerHTML == "", container.innerHTML
-        # Let's create the element
-        try:
-            klass = getattr(web, "img")
-            el = klass(*args, **kwargs)
-            container.append(el)
-        except Exception as e:
-            assert False, f"Failed to create element img: {e}"
-
-        if RUNNING_IN_WORKER:
-            # Needed to sync the DOM with the worker.
-            await asyncio.sleep(0.5)
-
-        # Check the img element was created correctly and all its properties
-        # were set correctly.
-        for k, v in properties.items():
-            assert v == getattr(el, k), f"{k} should be {v} but is {getattr(el, k)}"
+        self._create_el_and_basic_asserts("img", properties=properties)
 
     def test_input(self):
         # TODO: we need multiple input tests

core/tests/python/tests/test_when.py

@@ -1,216 +0,0 @@
-"""
-Tests for the pyscript.when decorator.
-"""
-
-import asyncio
-
-import upytest
-from pyscript import RUNNING_IN_WORKER, web
-
-
-def get_container():
-    return web.page.find("#test-element-container")[0]
-
-
-def setup():
-    container = get_container()
-    container.innerHTML = ""
-
-
-def teardown():
-    container = get_container()
-    container.innerHTML = ""
-
-
-async def test_when_decorator_with_event():
-    """
-    When the decorated function takes a single parameter,
-    it should be passed the event object
-    """
-    btn = web.button("foo_button", id="foo_id")
-    container = get_container()
-    container.append(btn)
-
-    called = False
-    call_flag = asyncio.Event()
-
-    @web.when("click", selector="#foo_id")
-    def foo(evt):
-        nonlocal called
-        called = evt
-        call_flag.set()
-
-    btn.click()
-    await call_flag.wait()
-    assert called.target.id == "foo_id"
-
-
-async def test_when_decorator_without_event():
-    """
-    When the decorated function takes no parameters (not including 'self'),
-    it should be called without the event object
-    """
-    btn = web.button("foo_button", id="foo_id")
-    container = get_container()
-    container.append(btn)
-
-    called = False
-    call_flag = asyncio.Event()
-
-    @web.when("click", selector="#foo_id")
-    def foo():
-        nonlocal called
-        called = True
-        call_flag.set()
-
-    btn.click()
-    await call_flag.wait()
-    assert called
-
-
-async def test_two_when_decorators():
-    """
-    When decorating a function twice, both should function
-    """
-    btn = web.button("foo_button", id="foo_id")
-    container = get_container()
-    container.append(btn)
-
-    called1 = False
-    called2 = False
-    call_flag1 = asyncio.Event()
-    call_flag2 = asyncio.Event()
-
-    @web.when("click", selector="#foo_id")
-    def foo1(evt):
-        nonlocal called1
-        called1 = True
-        call_flag1.set()
-
-    @web.when("click", selector="#foo_id")
-    def foo2(evt):
-        nonlocal called2
-        called2 = True
-        call_flag2.set()
-
-    btn.click()
-    await call_flag1.wait()
-    await call_flag2.wait()
-    assert called1
-    assert called2
-
-
-async def test_two_when_decorators_same_element():
-    """
-    When decorating a function twice *on the same DOM element*, both should
-    function
-    """
-    btn = web.button("foo_button", id="foo_id")
-    container = get_container()
-    container.append(btn)
-
-    counter = 0
-    call_flag = asyncio.Event()
-
-    @web.when("click", selector="#foo_id")
-    @web.when("click", selector="#foo_id")
-    def foo(evt):
-        nonlocal counter
-        counter += 1
-        call_flag.set()
-
-    assert counter == 0, counter
-    btn.click()
-    await call_flag.wait()
-    assert counter == 2, counter
-
-
-async def test_when_decorator_multiple_elements():
-    """
-    The @when decorator's selector should successfully select multiple
-    DOM elements
-    """
-    btn1 = web.button(
-        "foo_button1",
-        id="foo_id1",
-        classes=[
-            "foo_class",
-        ],
-    )
-    btn2 = web.button(
-        "foo_button2",
-        id="foo_id2",
-        classes=[
-            "foo_class",
-        ],
-    )
-    container = get_container()
-    container.append(btn1)
-    container.append(btn2)
-
-    counter = 0
-    call_flag1 = asyncio.Event()
-    call_flag2 = asyncio.Event()
-
-    @web.when("click", selector=".foo_class")
-    def foo(evt):
-        nonlocal counter
-        counter += 1
-        if evt.target.id == "foo_id1":
-            call_flag1.set()
-        else:
-            call_flag2.set()
-
-    assert counter == 0, counter
-    btn1.click()
-    await call_flag1.wait()
-    assert counter == 1, counter
-    btn2.click()
-    await call_flag2.wait()
-    assert counter == 2, counter
-
-
-async def test_when_decorator_duplicate_selectors():
-    """
-    When is not idempotent, so it should be possible to add multiple
-    @when decorators with the same selector.
-    """
-    btn = web.button("foo_button", id="foo_id")
-    container = get_container()
-    container.append(btn)
-
-    counter = 0
-    call_flag = asyncio.Event()
-
-    @web.when("click", selector="#foo_id")
-    @web.when("click", selector="#foo_id")  # duplicate
-    def foo1(evt):
-        nonlocal counter
-        counter += 1
-        call_flag.set()
-
-    assert counter == 0, counter
-    btn.click()
-    await call_flag.wait()
-    assert counter == 2, counter
-
-
-@upytest.skip(
-    "Only works in Pyodide on main thread",
-    skip_when=upytest.is_micropython or RUNNING_IN_WORKER,
-)
-def test_when_decorator_invalid_selector():
-    """
-    When the selector parameter of @when is invalid, it should raise an error.
-    """
-    if upytest.is_micropython:
-        from jsffi import JsException
-    else:
-        from pyodide.ffi import JsException
-
-    with upytest.raises(JsException) as e:
-
-        @web.when("click", selector="#.bad")
-        def foo(evt): ...
-
-    assert "'#.bad' is not a valid selector" in str(e.exception), str(e.exception)

core/types/3rd-party/xterm-readline.d.ts

@@ -1,6 +1,6 @@
-declare var b: any;
-declare var I: boolean;
-declare namespace r {
+declare var v: any;
+declare var k: boolean;
+declare namespace i {
     export let __esModule: boolean;
     export { Readline };
 }
@@ -57,7 +57,7 @@ declare class Readline {
         highlighter: any;
         history: any;
         promptSize: any;
-        layout: p;
+        layout: c;
         buffer(): string;
         shouldHighlight(): boolean;
         clearScreen(): void;
@@ -124,15 +124,15 @@ declare class Readline {
     readPaste(t: any): void;
     readKey(t: any): void;
 }
-declare class p {
+declare class c {
     constructor(t: any);
     promptSize: any;
-    cursor: c;
-    end: c;
+    cursor: u;
+    end: u;
 }
-declare class c {
+declare class u {
     constructor(t: any, e: any);
     row: any;
     col: any;
 }
-export { b as Readline, I as __esModule, r as default };
+export { v as Readline, k as __esModule, i as default };

core/types/3rd-party/xterm.d.ts

@@ -1,4 +1,4 @@
-declare var i: any;
-declare var s: any;
-declare var t: {};
-export { i as Terminal, s as __esModule, t as default };
+declare var D: any;
+declare var R: any;
+declare var L: {};
+export { D as Terminal, R as __esModule, L as default };

core/types/core.d.ts

@@ -7,6 +7,7 @@ export function donkey(options: any): Promise<{
     kill: () => void;
 }>;
 export function offline_interpreter(config: any): string;
+import codemirror from "./plugins/codemirror.js";
 import { stdlib } from "./stdlib.js";
 import { optional } from "./stdlib.js";
 import { inputFailure } from "./hooks.js";
@@ -63,4 +64,4 @@ declare const exportedHooks: {
 };
 declare const exportedConfig: {};
 declare const exportedWhenDefined: any;
-export { stdlib, optional, inputFailure, TYPES, relative_url, exportedPyWorker as PyWorker, exportedMPWorker as MPWorker, exportedHooks as hooks, exportedConfig as config, exportedWhenDefined as whenDefined };
+export { codemirror, stdlib, optional, inputFailure, TYPES, relative_url, exportedPyWorker as PyWorker, exportedMPWorker as MPWorker, exportedHooks as hooks, exportedConfig as config, exportedWhenDefined as whenDefined };

core/types/plugins.d.ts

@@ -1,4 +1,5 @@
 declare const _default: {
+    codemirror: () => Promise<typeof import("./plugins/codemirror.js")>;
     "deprecations-manager": () => Promise<typeof import("./plugins/deprecations-manager.js")>;
     donkey: () => Promise<typeof import("./plugins/donkey.js")>;
     error: () => Promise<typeof import("./plugins/error.js")>;

core/types/plugins/codemirror.d.ts

@@ -0,0 +1,9 @@
+declare namespace _default {
+    const core: Promise<typeof import("../3rd-party/codemirror.js")>;
+    const state: Promise<typeof import("../3rd-party/codemirror_state.js")>;
+    const python: Promise<typeof import("../3rd-party/codemirror_lang-python.js")>;
+    const language: Promise<typeof import("../3rd-party/codemirror_language.js")>;
+    const view: Promise<typeof import("../3rd-party/codemirror_view.js")>;
+    const commands: Promise<typeof import("../3rd-party/codemirror_commands.js")>;
+}
+export default _default;

core/types/stdlib/pyscript.d.ts

@@ -2,7 +2,7 @@ declare namespace _default {
     let pyscript: {
         "__init__.py": string;
         "display.py": string;
-        "event_handling.py": string;
+        "events.py": string;
         "fetch.py": string;
         "ffi.py": string;
         "flatted.py": string;