1 files changed, 442 insertions, 0 deletions
diff --git a/preact/debug/src/debug.js b/preact/debug/src/debug.js
new file mode 100644
index 0000000..27927cb
--- /dev/null
+++ b/preact/debug/src/debug.js
@@ -0,0 +1,442 @@
+import { checkPropTypes } from './check-props';
+import { options, Component } from 'preact';
+import {
+	ELEMENT_NODE,
+	DOCUMENT_NODE,
+	DOCUMENT_FRAGMENT_NODE
+} from './constants';
+import {
+	getOwnerStack,
+	setupComponentStack,
+	getCurrentVNode,
+	getDisplayName
+} from './component-stack';
+import { assign } from './util';
+
+const isWeakMapSupported = typeof WeakMap == 'function';
+
+function getClosestDomNodeParent(parent) {
+	if (!parent) return {};
+	if (typeof parent.type == 'function') {
+		return getClosestDomNodeParent(parent._parent);
+	}
+	return parent;
+}
+
+export function initDebug() {
+	setupComponentStack();
+
+	let hooksAllowed = false;
+
+	/* eslint-disable no-console */
+	let oldBeforeDiff = options._diff;
+	let oldDiffed = options.diffed;
+	let oldVnode = options.vnode;
+	let oldCatchError = options._catchError;
+	let oldRoot = options._root;
+	let oldHook = options._hook;
+	const warnedComponents = !isWeakMapSupported
+		? null
+		: {
+				useEffect: new WeakMap(),
+				useLayoutEffect: new WeakMap(),
+				lazyPropTypes: new WeakMap()
+		  };
+	const deprecations = [];
+
+	options._catchError = (error, vnode, oldVNode) => {
+		let component = vnode && vnode._component;
+		if (component && typeof error.then == 'function') {
+			const promise = error;
+			error = new Error(
+				`Missing Suspense. The throwing component was: ${getDisplayName(vnode)}`
+			);
+
+			let parent = vnode;
+			for (; parent; parent = parent._parent) {
+				if (parent._component && parent._component._childDidSuspend) {
+					error = promise;
+					break;
+				}
+			}
+
+			// We haven't recovered and we know at this point that there is no
+			// Suspense component higher up in the tree
+			if (error instanceof Error) {
+				throw error;
+			}
+		}
+
+		try {
+			oldCatchError(error, vnode, oldVNode);
+
+			// when an error was handled by an ErrorBoundary we will nontheless emit an error
+			// event on the window object. This is to make up for react compatibility in dev mode
+			// and thus make the Next.js dev overlay work.
+			if (typeof error.then != 'function') {
+				setTimeout(() => {
+					throw error;
+				});
+			}
+		} catch (e) {
+			throw e;
+		}
+	};
+
+	options._root = (vnode, parentNode) => {
+		if (!parentNode) {
+			throw new Error(
+				'Undefined parent passed to render(), this is the second argument.\n' +
+					'Check if the element is available in the DOM/has the correct id.'
+			);
+		}
+
+		let isValid;
+		switch (parentNode.nodeType) {
+			case ELEMENT_NODE:
+			case DOCUMENT_FRAGMENT_NODE:
+			case DOCUMENT_NODE:
+				isValid = true;
+				break;
+			default:
+				isValid = false;
+		}
+
+		if (!isValid) {
+			let componentName = getDisplayName(vnode);
+			throw new Error(
+				`Expected a valid HTML node as a second argument to render.	Received ${parentNode} instead: render(<${componentName} />, ${parentNode});`
+			);
+		}
+
+		if (oldRoot) oldRoot(vnode, parentNode);
+	};
+
+	options._diff = vnode => {
+		let { type, _parent: parent } = vnode;
+		let parentVNode = getClosestDomNodeParent(parent);
+
+		hooksAllowed = true;
+
+		if (type === undefined) {
+			throw new Error(
+				'Undefined component passed to createElement()\n\n' +
+					'You likely forgot to export your component or might have mixed up default and named imports' +
+					serializeVNode(vnode) +
+					`\n\n${getOwnerStack(vnode)}`
+			);
+		} else if (type != null && typeof type == 'object') {
+			if (type._children !== undefined && type._dom !== undefined) {
+				throw new Error(
+					`Invalid type passed to createElement(): ${type}\n\n` +
+						'Did you accidentally pass a JSX literal as JSX twice?\n\n' +
+						`  let My${getDisplayName(vnode)} = ${serializeVNode(type)};\n` +
+						`  let vnode = <My${getDisplayName(vnode)} />;\n\n` +
+						'This usually happens when you export a JSX literal and not the component.' +
+						`\n\n${getOwnerStack(vnode)}`
+				);
+			}
+
+			throw new Error(
+				'Invalid type passed to createElement(): ' +
+					(Array.isArray(type) ? 'array' : type)
+			);
+		}
+
+		if (
+			(type === 'thead' || type === 'tfoot' || type === 'tbody') &&
+			parentVNode.type !== 'table'
+		) {
+			console.error(
+				'Improper nesting of table. Your <thead/tbody/tfoot> should have a <table> parent.' +
+					serializeVNode(vnode) +
+					`\n\n${getOwnerStack(vnode)}`
+			);
+		} else if (
+			type === 'tr' &&
+			parentVNode.type !== 'thead' &&
+			parentVNode.type !== 'tfoot' &&
+			parentVNode.type !== 'tbody' &&
+			parentVNode.type !== 'table'
+		) {
+			console.error(
+				'Improper nesting of table. Your <tr> should have a <thead/tbody/tfoot/table> parent.' +
+					serializeVNode(vnode) +
+					`\n\n${getOwnerStack(vnode)}`
+			);
+		} else if (type === 'td' && parentVNode.type !== 'tr') {
+			console.error(
+				'Improper nesting of table. Your <td> should have a <tr> parent.' +
+					serializeVNode(vnode) +
+					`\n\n${getOwnerStack(vnode)}`
+			);
+		} else if (type === 'th' && parentVNode.type !== 'tr') {
+			console.error(
+				'Improper nesting of table. Your <th> should have a <tr>.' +
+					serializeVNode(vnode) +
+					`\n\n${getOwnerStack(vnode)}`
+			);
+		}
+
+		if (
+			vnode.ref !== undefined &&
+			typeof vnode.ref != 'function' &&
+			typeof vnode.ref != 'object' &&
+			!('$$typeof' in vnode) // allow string refs when preact-compat is installed
+		) {
+			throw new Error(
+				`Component's "ref" property should be a function, or an object created ` +
+					`by createRef(), but got [${typeof vnode.ref}] instead\n` +
+					serializeVNode(vnode) +
+					`\n\n${getOwnerStack(vnode)}`
+			);
+		}
+
+		if (typeof vnode.type == 'string') {
+			for (const key in vnode.props) {
+				if (
+					key[0] === 'o' &&
+					key[1] === 'n' &&
+					typeof vnode.props[key] != 'function' &&
+					vnode.props[key] != null
+				) {
+					throw new Error(
+						`Component's "${key}" property should be a function, ` +
+							`but got [${typeof vnode.props[key]}] instead\n` +
+							serializeVNode(vnode) +
+							`\n\n${getOwnerStack(vnode)}`
+					);
+				}
+			}
+		}
+
+		// Check prop-types if available
+		if (typeof vnode.type == 'function' && vnode.type.propTypes) {
+			if (
+				vnode.type.displayName === 'Lazy' &&
+				warnedComponents &&
+				!warnedComponents.lazyPropTypes.has(vnode.type)
+			) {
+				const m =
+					'PropTypes are not supported on lazy(). Use propTypes on the wrapped component itself. ';
+				try {
+					const lazyVNode = vnode.type();
+					warnedComponents.lazyPropTypes.set(vnode.type, true);
+					console.warn(
+						m + `Component wrapped in lazy() is ${getDisplayName(lazyVNode)}`
+					);
+				} catch (promise) {
+					console.warn(
+						m + "We will log the wrapped component's name once it is loaded."
+					);
+				}
+			}
+
+			let values = vnode.props;
+			if (vnode.type._forwarded) {
+				values = assign({}, values);
+				delete values.ref;
+			}
+
+			checkPropTypes(
+				vnode.type.propTypes,
+				values,
+				'prop',
+				getDisplayName(vnode),
+				() => getOwnerStack(vnode)
+			);
+		}
+
+		if (oldBeforeDiff) oldBeforeDiff(vnode);
+	};
+
+	options._hook = (comp, index, type) => {
+		if (!comp || !hooksAllowed) {
+			throw new Error('Hook can only be invoked from render methods.');
+		}
+
+		if (oldHook) oldHook(comp, index, type);
+	};
+
+	// Ideally we'd want to print a warning once per component, but we
+	// don't have access to the vnode that triggered it here. As a
+	// compromise and to avoid flooding the console with warnings we
+	// print each deprecation warning only once.
+	const warn = (property, message) => ({
+		get() {
+			const key = 'get' + property + message;
+			if (deprecations && deprecations.indexOf(key) < 0) {
+				deprecations.push(key);
+				console.warn(`getting vnode.${property} is deprecated, ${message}`);
+			}
+		},
+		set() {
+			const key = 'set' + property + message;
+			if (deprecations && deprecations.indexOf(key) < 0) {
+				deprecations.push(key);
+				console.warn(`setting vnode.${property} is not allowed, ${message}`);
+			}
+		}
+	});
+
+	const deprecatedAttributes = {
+		nodeName: warn('nodeName', 'use vnode.type'),
+		attributes: warn('attributes', 'use vnode.props'),
+		children: warn('children', 'use vnode.props.children')
+	};
+
+	const deprecatedProto = Object.create({}, deprecatedAttributes);
+
+	options.vnode = vnode => {
+		const props = vnode.props;
+		if (
+			vnode.type !== null &&
+			props != null &&
+			('__source' in props || '__self' in props)
+		) {
+			const newProps = (vnode.props = {});
+			for (let i in props) {
+				const v = props[i];
+				if (i === '__source') vnode.__source = v;
+				else if (i === '__self') vnode.__self = v;
+				else newProps[i] = v;
+			}
+		}
+
+		// eslint-disable-next-line
+		vnode.__proto__ = deprecatedProto;
+		if (oldVnode) oldVnode(vnode);
+	};
+
+	options.diffed = vnode => {
+		// Check if the user passed plain objects as children. Note that we cannot
+		// move this check into `options.vnode` because components can receive
+		// children in any shape they want (e.g.
+		// `<MyJSONFormatter>{{ foo: 123, bar: "abc" }}</MyJSONFormatter>`).
+		// Putting this check in `options.diffed` ensures that
+		// `vnode._children` is set and that we only validate the children
+		// that were actually rendered.
+		if (vnode._children) {
+			vnode._children.forEach(child => {
+				if (child && child.type === undefined) {
+					// Remove internal vnode keys that will always be patched
+					delete child._parent;
+					delete child._depth;
+					const keys = Object.keys(child).join(',');
+					throw new Error(
+						`Objects are not valid as a child. Encountered an object with the keys {${keys}}.` +
+							`\n\n${getOwnerStack(vnode)}`
+					);
+				}
+			});
+		}
+
+		hooksAllowed = false;
+
+		if (oldDiffed) oldDiffed(vnode);
+
+		if (vnode._children != null) {
+			const keys = [];
+			for (let i = 0; i < vnode._children.length; i++) {
+				const child = vnode._children[i];
+				if (!child || child.key == null) continue;
+
+				const key = child.key;
+				if (keys.indexOf(key) !== -1) {
+					console.error(
+						'Following component has two or more children with the ' +
+							`same key attribute: "${key}". This may cause glitches and misbehavior ` +
+							'in rendering process. Component: \n\n' +
+							serializeVNode(vnode) +
+							`\n\n${getOwnerStack(vnode)}`
+					);
+
+					// Break early to not spam the console
+					break;
+				}
+
+				keys.push(key);
+			}
+		}
+	};
+}
+
+const setState = Component.prototype.setState;
+Component.prototype.setState = function(update, callback) {
+	if (this._vnode == null) {
+		// `this._vnode` will be `null` during componentWillMount. But it
+		// is perfectly valid to call `setState` during cWM. So we
+		// need an additional check to verify that we are dealing with a
+		// call inside constructor.
+		if (this.state == null) {
+			console.warn(
+				`Calling "this.setState" inside the constructor of a component is a ` +
+					`no-op and might be a bug in your application. Instead, set ` +
+					`"this.state = {}" directly.\n\n${getOwnerStack(getCurrentVNode())}`
+			);
+		}
+	} else if (this._parentDom == null) {
+		console.warn(
+			`Can't call "this.setState" on an unmounted component. This is a no-op, ` +
+				`but it indicates a memory leak in your application. To fix, cancel all ` +
+				`subscriptions and asynchronous tasks in the componentWillUnmount method.` +
+				`\n\n${getOwnerStack(this._vnode)}`
+		);
+	}
+
+	return setState.call(this, update, callback);
+};
+
+const forceUpdate = Component.prototype.forceUpdate;
+Component.prototype.forceUpdate = function(callback) {
+	if (this._vnode == null) {
+		console.warn(
+			`Calling "this.forceUpdate" inside the constructor of a component is a ` +
+				`no-op and might be a bug in your application.\n\n${getOwnerStack(
+					getCurrentVNode()
+				)}`
+		);
+	} else if (this._parentDom == null) {
+		console.warn(
+			`Can't call "this.forceUpdate" on an unmounted component. This is a no-op, ` +
+				`but it indicates a memory leak in your application. To fix, cancel all ` +
+				`subscriptions and asynchronous tasks in the componentWillUnmount method.` +
+				`\n\n${getOwnerStack(this._vnode)}`
+		);
+	}
+	return forceUpdate.call(this, callback);
+};
+
+/**
+ * Serialize a vnode tree to a string
+ * @param {import('./internal').VNode} vnode
+ * @returns {string}
+ */
+export function serializeVNode(vnode) {
+	let { props } = vnode;
+	let name = getDisplayName(vnode);
+
+	let attrs = '';
+	for (let prop in props) {
+		if (props.hasOwnProperty(prop) && prop !== 'children') {
+			let value = props[prop];
+
+			// If it is an object but doesn't have toString(), use Object.toString
+			if (typeof value == 'function') {
+				value = `function ${value.displayName || value.name}() {}`;
+			}
+
+			value =
+				Object(value) === value && !value.toString
+					? Object.prototype.toString.call(value)
+					: value + '';
+
+			attrs += ` ${prop}=${JSON.stringify(value)}`;
+		}
+	}
+
+	let children = props.children;
+	return `<${name}${attrs}${
+		children && children.length ? '>..</' + name + '>' : ' />'
+	}`;
+}