From c38ae94df9b6333390c5b290d03c592515ae475a Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Thu, 14 Mar 2024 11:33:32 +0100
Subject: [PATCH 01/23] Strict type checking

---
 packages/interactivity/tsconfig.json | 11 +++++++++--
 tsconfig.base.json                   |  2 +-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/packages/interactivity/tsconfig.json b/packages/interactivity/tsconfig.json
index 0fb91956773f89..445fce42e73e54 100644
--- a/packages/interactivity/tsconfig.json
+++ b/packages/interactivity/tsconfig.json
@@ -4,8 +4,15 @@
 	"compilerOptions": {
 		"rootDir": "src",
 		"declarationDir": "build-types",
-		"checkJs": false,
-		"strict": false
+
+		"alwaysStrict": false,
+		"strictNullChecks": false,
+		"strictBindCallApply": false,
+		"strictFunctionTypes": false,
+		"strictPropertyInitialization": false,
+		"noImplicitAny": false,
+		"noImplicitThis": false,
+		"useUnknownInCatchVariables": false
 	},
 	"include": [ "src/**/*" ]
 }
diff --git a/tsconfig.base.json b/tsconfig.base.json
index 1b30522ee52366..18388b7f71854c 100644
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@@ -7,7 +7,7 @@
 		"jsx": "preserve",
 		"target": "esnext",
 		"module": "esnext",
-		"lib": [ "dom", "esnext" ],
+		"lib": [ "DOM", "DOM.Iterable", "ESNext" ],
 		"declaration": true,
 		"declarationMap": true,
 		"composite": true,

From 613531cc499404a1422f904098a797acf75ca0b7 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 16:09:26 +0200
Subject: [PATCH 02/23] rename to tsx

---
 packages/interactivity/src/{directives.js => directives.tsx} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename packages/interactivity/src/{directives.js => directives.tsx} (100%)

diff --git a/packages/interactivity/src/directives.js b/packages/interactivity/src/directives.tsx
similarity index 100%
rename from packages/interactivity/src/directives.js
rename to packages/interactivity/src/directives.tsx

From d65fc7a9a360c65289db65fb4222c0fb2fafa40d Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 17:01:54 +0200
Subject: [PATCH 03/23] isPlainObject

---
 packages/interactivity/src/directives.tsx | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/interactivity/src/directives.tsx b/packages/interactivity/src/directives.tsx
index 8100ac7a52eee5..67fe9d92f2714a 100644
--- a/packages/interactivity/src/directives.tsx
+++ b/packages/interactivity/src/directives.tsx
@@ -23,8 +23,8 @@ const contextObjectToProxy = new WeakMap();
 const contextProxyToObject = new WeakMap();
 const contextObjectToFallback = new WeakMap();
 
-const isPlainObject = ( item ) =>
-	item && typeof item === 'object' && item.constructor === Object;
+const isPlainObject = ( item: unknown ): boolean =>
+	Boolean( item && typeof item === 'object' && item.constructor === Object );
 
 const descriptor = Reflect.getOwnPropertyDescriptor;
 

From 89a5d8e3c1f14ebe3d3e6eee6993aed382f16c8c Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 17:05:34 +0200
Subject: [PATCH 04/23] hooks types

---
 packages/interactivity/src/hooks.tsx | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/packages/interactivity/src/hooks.tsx b/packages/interactivity/src/hooks.tsx
index 353959ea5b2ea6..be90889dc69952 100644
--- a/packages/interactivity/src/hooks.tsx
+++ b/packages/interactivity/src/hooks.tsx
@@ -1,5 +1,8 @@
 /* @jsx createElement */
 
+// eslint-disable-next-line eslint-comments/disable-enable-pair
+/* eslint-disable react-hooks/exhaustive-deps */
+
 /**
  * External dependencies
  */
@@ -18,7 +21,7 @@ import type { VNode, Context, RefObject } from 'preact';
 import { store, stores, universalUnlock } from './store';
 import { warn } from './utils/warn';
 interface DirectiveEntry {
-	value: string | Object;
+	value: string | object;
 	namespace: string;
 	suffix: string;
 }
@@ -102,7 +105,7 @@ const immutableError = () => {
 		'Please use `data-wp-bind` to modify the attributes of an element.'
 	);
 };
-const immutableHandlers = {
+const immutableHandlers: ProxyHandler< object > = {
 	get( target, key, receiver ) {
 		const value = Reflect.get( target, key, receiver );
 		return !! value && typeof value === 'object'
@@ -112,7 +115,7 @@ const immutableHandlers = {
 	set: immutableError,
 	deleteProperty: immutableError,
 };
-const deepImmutable = < T extends Object = {} >( target: T ): T => {
+const deepImmutable = < T extends object = {} >( target: T ): T => {
 	if ( ! immutableMap.has( target ) ) {
 		immutableMap.set( target, new Proxy( target, immutableHandlers ) );
 	}
@@ -260,7 +263,7 @@ export const directive = (
 };
 
 // Resolve the path to some property of the store object.
-const resolve = ( path, namespace ) => {
+const resolve = ( path: string, namespace: string ) => {
 	if ( ! namespace ) {
 		warn(
 			`The "namespace" cannot be "{}", "null" or an empty string. Path: ${ path }`

From 6b5002f7a279f2738d8bdb19a3836651a7e6b295 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 17:47:58 +0200
Subject: [PATCH 05/23] types

---
 packages/interactivity/src/directives.tsx | 65 +++++++++++++----------
 packages/interactivity/src/hooks.tsx      | 10 ++--
 2 files changed, 45 insertions(+), 30 deletions(-)

diff --git a/packages/interactivity/src/directives.tsx b/packages/interactivity/src/directives.tsx
index 67fe9d92f2714a..a1cae36e63d262 100644
--- a/packages/interactivity/src/directives.tsx
+++ b/packages/interactivity/src/directives.tsx
@@ -1,9 +1,12 @@
+// eslint-disable-next-line eslint-comments/disable-enable-pair
+/* eslint-disable react-hooks/exhaustive-deps */
+
 /* @jsx createElement */
 
 /**
  * External dependencies
  */
-import { h as createElement } from 'preact';
+import { h as createElement, type RefObject } from 'preact';
 import { useContext, useMemo, useRef } from 'preact/hooks';
 import { deepSignal, peek } from 'deepsignal';
 
@@ -37,12 +40,12 @@ const descriptor = Reflect.getOwnPropertyDescriptor;
  * By default, all plain objects inside the context are wrapped, unless it is
  * listed in the `ignore` option.
  *
- * @param {Object} current   Current context.
- * @param {Object} inherited Inherited context, used as fallback.
+ * @param current   Current context.
+ * @param inherited Inherited context, used as fallback.
  *
- * @return {Object} The wrapped context object.
+ * @return The wrapped context object.
  */
-const proxifyContext = ( current, inherited = {} ) => {
+const proxifyContext = ( current: object, inherited: object = {} ): object => {
 	// Update the fallback object reference when it changes.
 	contextObjectToFallback.set( current, inherited );
 	if ( ! contextObjectToProxy.has( current ) ) {
@@ -127,10 +130,10 @@ const proxifyContext = ( current, inherited = {} ) => {
 /**
  * Recursively update values within a deepSignal object.
  *
- * @param {Object} target A deepSignal instance.
- * @param {Object} source Object with properties to update in `target`
+ * @param target A deepSignal instance.
+ * @param source Object with properties to update in `target`
  */
-const updateSignals = ( target, source ) => {
+const updateSignals = ( target: object, source: object ) => {
 	for ( const k in source ) {
 		if (
 			isPlainObject( peek( target, k ) ) &&
@@ -146,23 +149,23 @@ const updateSignals = ( target, source ) => {
 /**
  * Recursively clone the passed object.
  *
- * @param {Object} source Source object.
- * @return {Object} Cloned object.
+ * @param source Source object.
+ * @return Cloned object.
  */
-const deepClone = ( source ) => {
+function deepClone< T >( source: T ): T {
 	if ( isPlainObject( source ) ) {
 		return Object.fromEntries(
-			Object.entries( source ).map( ( [ key, value ] ) => [
+			Object.entries( source as object ).map( ( [ key, value ] ) => [
 				key,
 				deepClone( value ),
 			] )
-		);
+		) as T;
 	}
 	if ( Array.isArray( source ) ) {
-		return source.map( ( i ) => deepClone( i ) );
+		return source.map( ( i ) => deepClone( i ) ) as T;
 	}
 	return source;
-};
+}
 
 const newRule =
 	/(?:([\u0080-\uFFFF\w-%@]+) *:? *([^{;]+?);|([^;}{]*?) *{)|(}\s*)/g;
@@ -176,10 +179,10 @@ const empty = ' ';
  * Made by Cristian Bote (@cristianbote) for Goober.
  * https://unpkg.com/browse/goober@2.1.13/src/core/astish.js
  *
- * @param {string} val CSS string.
- * @return {Object} CSS object.
+ * @param val CSS string.
+ * @return CSS object.
  */
-const cssStringToObject = ( val ) => {
+const cssStringToObject = ( val: string ): object => {
 	const tree = [ {} ];
 	let block, left;
 
@@ -203,10 +206,9 @@ const cssStringToObject = ( val ) => {
  * Creates a directive that adds an event listener to the global window or
  * document object.
  *
- * @param {string} type 'window' or 'document'
- * @return {void}
+ * @param type 'window' or 'document'
  */
-const getGlobalEventDirective = ( type ) => {
+const getGlobalEventDirective = ( type: 'window' | 'document' ) => {
 	return ( { directives, evaluate } ) => {
 		directives[ `on-${ type }` ]
 			.filter( ( { suffix } ) => suffix !== 'default' )
@@ -217,7 +219,7 @@ const getGlobalEventDirective = ( type ) => {
 					const globalVar = type === 'window' ? window : document;
 					globalVar.addEventListener( eventName, cb );
 					return () => globalVar.removeEventListener( eventName, cb );
-				}, [] );
+				} );
 			} );
 	};
 };
@@ -333,9 +335,13 @@ export default () => {
 						 * need deps because it only needs to do it the first time.
 						 */
 						if ( ! result ) {
-							element.ref.current.classList.remove( className );
+							(
+								element.ref as RefObject< HTMLElement >
+							 ).current!.classList.remove( className );
 						} else {
-							element.ref.current.classList.add( className );
+							(
+								element.ref as RefObject< HTMLElement >
+							 ).current!.classList.add( className );
 						}
 					} );
 				} );
@@ -368,9 +374,13 @@ export default () => {
 					 * because it only needs to do it the first time.
 					 */
 					if ( ! result ) {
-						element.ref.current.style.removeProperty( styleProp );
+						(
+							element.ref as RefObject< HTMLElement >
+						 ).current!.style.removeProperty( styleProp );
 					} else {
-						element.ref.current.style[ styleProp ] = result;
+						(
+							element.ref as RefObject< HTMLElement >
+						 ).current!.style[ styleProp ] = result;
 					}
 				} );
 			} );
@@ -390,7 +400,8 @@ export default () => {
 				 * first time. After that, Preact will handle the changes.
 				 */
 				useInit( () => {
-					const el = element.ref.current;
+					const el = ( element.ref as RefObject< HTMLElement > )
+						.current!;
 
 					/*
 					 * We set the value directly to the corresponding HTMLElement instance
diff --git a/packages/interactivity/src/hooks.tsx b/packages/interactivity/src/hooks.tsx
index be90889dc69952..655118726f79b5 100644
--- a/packages/interactivity/src/hooks.tsx
+++ b/packages/interactivity/src/hooks.tsx
@@ -11,6 +11,7 @@ import {
 	options,
 	createContext,
 	cloneElement,
+	type ComponentChildren,
 } from 'preact';
 import { useRef, useCallback, useContext } from 'preact/hooks';
 import type { VNode, Context, RefObject } from 'preact';
@@ -36,11 +37,14 @@ interface DirectiveArgs {
 	/**
 	 * Props present in the current element.
 	 */
-	props: Object;
+	props: { children?: ComponentChildren };
 	/**
 	 * Virtual node representing the element.
 	 */
-	element: VNode;
+	element: VNode< {
+		class?: string;
+		style?: string | Record< string, string | number >;
+	} >;
 	/**
 	 * The inherited context.
 	 */
@@ -53,7 +57,7 @@ interface DirectiveArgs {
 }
 
 interface DirectiveCallback {
-	( args: DirectiveArgs ): VNode | void;
+	( args: DirectiveArgs ): VNode | null;
 }
 
 interface DirectiveOptions {

From 78c697367ce05f7dfde9f7bf1e3c48ffcb9a7c17 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 18:11:32 +0200
Subject: [PATCH 06/23] types

---
 packages/interactivity/src/directives.tsx | 17 ++++++++++++-----
 packages/interactivity/src/hooks.tsx      |  5 +++--
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/packages/interactivity/src/directives.tsx b/packages/interactivity/src/directives.tsx
index a1cae36e63d262..1b94c3fc5d26ff 100644
--- a/packages/interactivity/src/directives.tsx
+++ b/packages/interactivity/src/directives.tsx
@@ -8,7 +8,7 @@
  */
 import { h as createElement, type RefObject } from 'preact';
 import { useContext, useMemo, useRef } from 'preact/hooks';
-import { deepSignal, peek } from 'deepsignal';
+import { deepSignal, peek, type DeepSignal } from 'deepsignal';
 
 /**
  * Internal dependencies
@@ -50,7 +50,7 @@ const proxifyContext = ( current: object, inherited: object = {} ): object => {
 	contextObjectToFallback.set( current, inherited );
 	if ( ! contextObjectToProxy.has( current ) ) {
 		const proxy = new Proxy( current, {
-			get: ( target, k ) => {
+			get: ( target: DeepSignal< any >, k ) => {
 				const fallback = contextObjectToFallback.get( current );
 				// Always subscribe to prop changes in the current context.
 				const currentProp = target[ k ];
@@ -131,9 +131,12 @@ const proxifyContext = ( current: object, inherited: object = {} ): object => {
  * Recursively update values within a deepSignal object.
  *
  * @param target A deepSignal instance.
- * @param source Object with properties to update in `target`
+ * @param source Object with properties to update in `target`.
  */
-const updateSignals = ( target: object, source: object ) => {
+const updateSignals = (
+	target: DeepSignal< any >,
+	source: DeepSignal< any >
+) => {
 	for ( const k in source ) {
 		if (
 			isPlainObject( peek( target, k ) ) &&
@@ -182,7 +185,9 @@ const empty = ' ';
  * @param val CSS string.
  * @return CSS object.
  */
-const cssStringToObject = ( val: string ): object => {
+const cssStringToObject = (
+	val: string
+): Record< string, string | number > => {
 	const tree = [ {} ];
 	let block, left;
 
@@ -473,6 +478,8 @@ export default () => {
 				type: Type,
 				props: { innerHTML, ...rest },
 			},
+		}: {
+			element: any;
 		} ) => {
 			// Preserve the initial inner HTML.
 			const cached = useMemo( () => innerHTML, [] );
diff --git a/packages/interactivity/src/hooks.tsx b/packages/interactivity/src/hooks.tsx
index 655118726f79b5..4fac736aeadafb 100644
--- a/packages/interactivity/src/hooks.tsx
+++ b/packages/interactivity/src/hooks.tsx
@@ -44,6 +44,7 @@ interface DirectiveArgs {
 	element: VNode< {
 		class?: string;
 		style?: string | Record< string, string | number >;
+		content?: ComponentChildren;
 	} >;
 	/**
 	 * The inherited context.
@@ -57,7 +58,7 @@ interface DirectiveArgs {
 }
 
 interface DirectiveCallback {
-	( args: DirectiveArgs ): VNode | null;
+	( args: DirectiveArgs ): VNode | null | void;
 }
 
 interface DirectiveOptions {
@@ -72,7 +73,7 @@ interface DirectiveOptions {
 
 interface Scope {
 	evaluate: Evaluate;
-	context: Context< any >;
+	context?: object;
 	ref: RefObject< HTMLElement >;
 	attributes: createElement.JSX.HTMLAttributes;
 }

From a64715f133efeadf6de71407669e1d280c33b2ec Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 18:13:14 +0200
Subject: [PATCH 07/23] =?UTF-8?q?stricter=E2=80=A6?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 packages/interactivity/tsconfig.json | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/packages/interactivity/tsconfig.json b/packages/interactivity/tsconfig.json
index 445fce42e73e54..ef79d9873e1989 100644
--- a/packages/interactivity/tsconfig.json
+++ b/packages/interactivity/tsconfig.json
@@ -5,14 +5,11 @@
 		"rootDir": "src",
 		"declarationDir": "build-types",
 
-		"alwaysStrict": false,
 		"strictNullChecks": false,
-		"strictBindCallApply": false,
-		"strictFunctionTypes": false,
 		"strictPropertyInitialization": false,
-		"noImplicitAny": false,
+
 		"noImplicitThis": false,
-		"useUnknownInCatchVariables": false
+		"noImplicitAny": false
 	},
 	"include": [ "src/**/*" ]
 }

From 2cbf09c5ffe0c195ba084d9ce47e40f31ca2e262 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 18:15:43 +0200
Subject: [PATCH 08/23] implicit this

---
 packages/interactivity/src/utils.ts  | 2 +-
 packages/interactivity/tsconfig.json | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/interactivity/src/utils.ts b/packages/interactivity/src/utils.ts
index 4759a7b27a74a6..c95b2421188efd 100644
--- a/packages/interactivity/src/utils.ts
+++ b/packages/interactivity/src/utils.ts
@@ -63,7 +63,7 @@ const afterNextFrame = ( callback: () => void ) => {
  */
 function createFlusher( compute: () => unknown, notify: () => void ): Flusher {
 	let flush: () => void;
-	const dispose = effect( function () {
+	const dispose = effect( function ( this: any ) {
 		flush = this.c.bind( this );
 		this.x = compute;
 		this.c = notify;
diff --git a/packages/interactivity/tsconfig.json b/packages/interactivity/tsconfig.json
index ef79d9873e1989..d991e2e56a9084 100644
--- a/packages/interactivity/tsconfig.json
+++ b/packages/interactivity/tsconfig.json
@@ -8,7 +8,6 @@
 		"strictNullChecks": false,
 		"strictPropertyInitialization": false,
 
-		"noImplicitThis": false,
 		"noImplicitAny": false
 	},
 	"include": [ "src/**/*" ]

From 3cacdc16add765c2f843e7bc7ef3fb8a2797fa8b Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 19:17:42 +0200
Subject: [PATCH 09/23] strict nulls

---
 packages/interactivity/src/vdom.ts   | 58 ++++++++++++++++++----------
 packages/interactivity/tsconfig.json |  1 -
 2 files changed, 38 insertions(+), 21 deletions(-)

diff --git a/packages/interactivity/src/vdom.ts b/packages/interactivity/src/vdom.ts
index 78f6d7032613a5..77458a9d6cc182 100644
--- a/packages/interactivity/src/vdom.ts
+++ b/packages/interactivity/src/vdom.ts
@@ -1,17 +1,19 @@
 /**
  * External dependencies
  */
-import { h } from 'preact';
+import { h, type VNode, type JSX } from 'preact';
 /**
  * Internal dependencies
  */
 import { directivePrefix as p } from './constants';
 import { warn } from './utils/warn';
 
+type TreeWalkerReturn = string | Node | VNode< any > | null;
+
 const ignoreAttr = `data-${ p }-ignore`;
 const islandAttr = `data-${ p }-interactive`;
 const fullPrefix = `data-${ p }-`;
-const namespaces = [];
+const namespaces: Array< string > = [];
 const currentNamespace = () => namespaces[ namespaces.length - 1 ] ?? null;
 
 // Regular expression for directive parsing.
@@ -39,35 +41,49 @@ export const hydratedIslands = new WeakSet();
 /**
  * Recursive function that transforms a DOM tree into vDOM.
  *
- * @param {Node} root The root element or node to start traversing on.
- * @return {import('preact').VNode[]} The resulting vDOM tree.
+ * @param root The root element or node to start traversing on.
+ * @return The resulting vDOM tree.
  */
-export function toVdom( root ) {
+export function toVdom( root: Node ): [ string | VNode | null, Node | null ] {
 	const treeWalker = document.createTreeWalker(
 		root,
 		205 // ELEMENT + TEXT + COMMENT + CDATA_SECTION + PROCESSING_INSTRUCTION
 	);
 
-	function walk( node ) {
-		const { attributes, nodeType, localName } = node;
+	function walk( node: Node ): [ string | VNode | null, Node | null ] {
+		const { nodeType } = node;
 
+		// TEXT_NODE (3)
 		if ( nodeType === 3 ) {
-			return [ node.data ];
+			return [ ( node as Text ).data, null ];
 		}
+
+		// CDATA_SECTION_NODE (4)
 		if ( nodeType === 4 ) {
 			const next = treeWalker.nextSibling();
-			node.replaceWith( new window.Text( node.nodeValue ) );
+			( node as CDATASection ).replaceWith(
+				new window.Text( ( node as CDATASection ).nodeValue ?? '' )
+			);
 			return [ node.nodeValue, next ];
 		}
+
+		// COMMENT_NODE (8) || PROCESSING_INSTRUCTION_NODE (7)
 		if ( nodeType === 8 || nodeType === 7 ) {
 			const next = treeWalker.nextSibling();
-			node.remove();
+			( node as Comment | ProcessingInstruction ).remove();
 			return [ null, next ];
 		}
 
+		const elementNode = node as HTMLElement;
+
+		const attributes = elementNode.attributes;
+		const localName = elementNode.localName as keyof JSX.IntrinsicElements;
+
 		const props: Record< string, any > = {};
-		const children = [];
-		const directives = [];
+		const children: Array< TreeWalkerReturn > = [];
+		const directives: Array<
+			[ name: string, namespace: string | null, value: unknown ]
+		> = [];
 		let ignore = false;
 		let island = false;
 
@@ -84,7 +100,7 @@ export function toVdom( root ) {
 						.exec( attributes[ i ].value )
 						?.slice( 1 ) ?? [ null, attributes[ i ].value ];
 					try {
-						value = JSON.parse( value );
+						value = JSON.parse( value as string );
 					} catch ( e ) {}
 					if ( n === islandAttr ) {
 						island = true;
@@ -105,15 +121,16 @@ export function toVdom( root ) {
 
 		if ( ignore && ! island ) {
 			return [
-				h( localName, {
+				h< any, any >( localName, {
 					...props,
-					innerHTML: node.innerHTML,
+					innerHTML: elementNode.innerHTML,
 					__directives: { ignore: true },
 				} ),
+				null,
 			];
 		}
 		if ( island ) {
-			hydratedIslands.add( node );
+			hydratedIslands.add( elementNode );
 		}
 
 		if ( directives.length ) {
@@ -139,10 +156,11 @@ export function toVdom( root ) {
 			);
 		}
 
+		// @ts-expect-error Fixed in upcoming preact release https://github.com/preactjs/preact/pull/4334
 		if ( localName === 'template' ) {
-			props.content = [ ...node.content.childNodes ].map( ( childNode ) =>
-				toVdom( childNode )
-			);
+			props.content = [
+				...( elementNode as HTMLTemplateElement ).content.childNodes,
+			].map( ( childNode ) => toVdom( childNode ) );
 		} else {
 			let child = treeWalker.firstChild();
 			if ( child ) {
@@ -162,7 +180,7 @@ export function toVdom( root ) {
 			namespaces.pop();
 		}
 
-		return [ h( localName, props, children ) ];
+		return [ h( localName, props, children ), null ];
 	}
 
 	return walk( treeWalker.currentNode );
diff --git a/packages/interactivity/tsconfig.json b/packages/interactivity/tsconfig.json
index d991e2e56a9084..bd921d194888ac 100644
--- a/packages/interactivity/tsconfig.json
+++ b/packages/interactivity/tsconfig.json
@@ -5,7 +5,6 @@
 		"rootDir": "src",
 		"declarationDir": "build-types",
 
-		"strictNullChecks": false,
 		"strictPropertyInitialization": false,
 
 		"noImplicitAny": false

From ff261d457621b86147b5845593a2da6b5a56937a Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 19:20:38 +0200
Subject: [PATCH 10/23] handle not found text entry

---
 packages/interactivity/src/directives.tsx | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/packages/interactivity/src/directives.tsx b/packages/interactivity/src/directives.tsx
index 1b94c3fc5d26ff..07328df8af210b 100644
--- a/packages/interactivity/src/directives.tsx
+++ b/packages/interactivity/src/directives.tsx
@@ -495,6 +495,11 @@ export default () => {
 	// data-wp-text
 	directive( 'text', ( { directives: { text }, element, evaluate } ) => {
 		const entry = text.find( ( { suffix } ) => suffix === 'default' );
+		if ( ! entry ) {
+			element.props.children = null;
+			return;
+		}
+
 		try {
 			const result = evaluate( entry );
 			element.props.children =

From 646ea331422be7bf4c02589ab5e56b7755980ea2 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 19:25:57 +0200
Subject: [PATCH 11/23] hooks

---
 packages/interactivity/src/utils.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/interactivity/src/utils.ts b/packages/interactivity/src/utils.ts
index c95b2421188efd..e201ff15a68927 100644
--- a/packages/interactivity/src/utils.ts
+++ b/packages/interactivity/src/utils.ts
@@ -62,7 +62,7 @@ const afterNextFrame = ( callback: () => void ) => {
  * @return The Flusher object with `flush` and `dispose` properties.
  */
 function createFlusher( compute: () => unknown, notify: () => void ): Flusher {
-	let flush: () => void;
+	let flush: () => void = () => undefined;
 	const dispose = effect( function ( this: any ) {
 		flush = this.c.bind( this );
 		this.x = compute;
@@ -82,7 +82,7 @@ function createFlusher( compute: () => unknown, notify: () => void ): Flusher {
  */
 export function useSignalEffect( callback: () => unknown ) {
 	_useEffect( () => {
-		let eff = null;
+		let eff: Flusher | null = null;
 		let isExecuting = false;
 
 		const notify = async () => {
@@ -273,7 +273,7 @@ export const createRootFragment = (
 	parent: Element,
 	replaceNode: Node | Node[]
 ) => {
-	replaceNode = [].concat( replaceNode );
+	replaceNode = ( [] as Node[] ).concat( replaceNode );
 	const sibling = replaceNode[ replaceNode.length - 1 ].nextSibling;
 	function insert( child: any, root: any ) {
 		parent.insertBefore( child, root || sibling );

From 7739b7498714a9bba58899bebfe5f0484c7bd9ca Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 19:27:11 +0200
Subject: [PATCH 12/23] store

---
 packages/interactivity/src/store.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/interactivity/src/store.ts b/packages/interactivity/src/store.ts
index 81905071702af2..87c9333c744296 100644
--- a/packages/interactivity/src/store.ts
+++ b/packages/interactivity/src/store.ts
@@ -17,7 +17,7 @@ import {
 } from './hooks';
 
 const isObject = ( item: unknown ): item is Record< string, unknown > =>
-	item && typeof item === 'object' && item.constructor === Object;
+	Boolean( item && typeof item === 'object' && item.constructor === Object );
 
 const deepMerge = ( target: any, source: any ) => {
 	if ( isObject( target ) && isObject( source ) ) {
@@ -338,12 +338,12 @@ export const populateInitialData = ( data?: {
 	config?: Record< string, unknown >;
 } ) => {
 	if ( isObject( data?.state ) ) {
-		Object.entries( data.state ).forEach( ( [ namespace, state ] ) => {
+		Object.entries( data!.state ).forEach( ( [ namespace, state ] ) => {
 			store( namespace, { state }, { lock: universalUnlock } );
 		} );
 	}
 	if ( isObject( data?.config ) ) {
-		Object.entries( data.config ).forEach( ( [ namespace, config ] ) => {
+		Object.entries( data!.config ).forEach( ( [ namespace, config ] ) => {
 			storeConfigs.set( namespace, config );
 		} );
 	}

From ec9f2e0ad8170d61c660456b0c2301411cd272cf Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 19:29:49 +0200
Subject: [PATCH 13/23] Scope

---
 packages/interactivity/src/hooks.tsx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/interactivity/src/hooks.tsx b/packages/interactivity/src/hooks.tsx
index 4fac736aeadafb..2dfc08a43f6fa8 100644
--- a/packages/interactivity/src/hooks.tsx
+++ b/packages/interactivity/src/hooks.tsx
@@ -73,7 +73,7 @@ interface DirectiveOptions {
 
 interface Scope {
 	evaluate: Evaluate;
-	context?: object;
+	context: object;
 	ref: RefObject< HTMLElement >;
 	attributes: createElement.JSX.HTMLAttributes;
 }

From 85283eb3e5efb9723faf44fcf7b533ed151ecaa8 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 19:31:49 +0200
Subject: [PATCH 14/23] I hate it

---
 packages/interactivity/src/vdom.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/interactivity/src/vdom.ts b/packages/interactivity/src/vdom.ts
index 77458a9d6cc182..894db31a5337d0 100644
--- a/packages/interactivity/src/vdom.ts
+++ b/packages/interactivity/src/vdom.ts
@@ -107,7 +107,7 @@ export function toVdom( root: Node ): [ string | VNode | null, Node | null ] {
 						namespaces.push(
 							typeof value === 'string'
 								? value
-								: value?.namespace ?? null
+								: ( value as any )?.namespace ?? null
 						);
 					} else {
 						directives.push( [ n, ns, value ] );

From 811043614daa9da9a93a140d322d9037cf7fb196 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 10 Apr 2024 19:32:46 +0200
Subject: [PATCH 15/23] More strict

---
 packages/interactivity/tsconfig.json | 2 --
 1 file changed, 2 deletions(-)

diff --git a/packages/interactivity/tsconfig.json b/packages/interactivity/tsconfig.json
index bd921d194888ac..1d154e2089065d 100644
--- a/packages/interactivity/tsconfig.json
+++ b/packages/interactivity/tsconfig.json
@@ -5,8 +5,6 @@
 		"rootDir": "src",
 		"declarationDir": "build-types",
 
-		"strictPropertyInitialization": false,
-
 		"noImplicitAny": false
 	},
 	"include": [ "src/**/*" ]

From 807e6ac500ea1104a0ecef73795c8b1f2c3c61c0 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 15 May 2024 18:17:00 +0200
Subject: [PATCH 16/23] restart and try again

---
 packages/interactivity/src/vdom.ts | 60 +++++++++++-------------------
 1 file changed, 21 insertions(+), 39 deletions(-)

diff --git a/packages/interactivity/src/vdom.ts b/packages/interactivity/src/vdom.ts
index 894db31a5337d0..78f6d7032613a5 100644
--- a/packages/interactivity/src/vdom.ts
+++ b/packages/interactivity/src/vdom.ts
@@ -1,19 +1,17 @@
 /**
  * External dependencies
  */
-import { h, type VNode, type JSX } from 'preact';
+import { h } from 'preact';
 /**
  * Internal dependencies
  */
 import { directivePrefix as p } from './constants';
 import { warn } from './utils/warn';
 
-type TreeWalkerReturn = string | Node | VNode< any > | null;
-
 const ignoreAttr = `data-${ p }-ignore`;
 const islandAttr = `data-${ p }-interactive`;
 const fullPrefix = `data-${ p }-`;
-const namespaces: Array< string > = [];
+const namespaces = [];
 const currentNamespace = () => namespaces[ namespaces.length - 1 ] ?? null;
 
 // Regular expression for directive parsing.
@@ -41,49 +39,35 @@ export const hydratedIslands = new WeakSet();
 /**
  * Recursive function that transforms a DOM tree into vDOM.
  *
- * @param root The root element or node to start traversing on.
- * @return The resulting vDOM tree.
+ * @param {Node} root The root element or node to start traversing on.
+ * @return {import('preact').VNode[]} The resulting vDOM tree.
  */
-export function toVdom( root: Node ): [ string | VNode | null, Node | null ] {
+export function toVdom( root ) {
 	const treeWalker = document.createTreeWalker(
 		root,
 		205 // ELEMENT + TEXT + COMMENT + CDATA_SECTION + PROCESSING_INSTRUCTION
 	);
 
-	function walk( node: Node ): [ string | VNode | null, Node | null ] {
-		const { nodeType } = node;
+	function walk( node ) {
+		const { attributes, nodeType, localName } = node;
 
-		// TEXT_NODE (3)
 		if ( nodeType === 3 ) {
-			return [ ( node as Text ).data, null ];
+			return [ node.data ];
 		}
-
-		// CDATA_SECTION_NODE (4)
 		if ( nodeType === 4 ) {
 			const next = treeWalker.nextSibling();
-			( node as CDATASection ).replaceWith(
-				new window.Text( ( node as CDATASection ).nodeValue ?? '' )
-			);
+			node.replaceWith( new window.Text( node.nodeValue ) );
 			return [ node.nodeValue, next ];
 		}
-
-		// COMMENT_NODE (8) || PROCESSING_INSTRUCTION_NODE (7)
 		if ( nodeType === 8 || nodeType === 7 ) {
 			const next = treeWalker.nextSibling();
-			( node as Comment | ProcessingInstruction ).remove();
+			node.remove();
 			return [ null, next ];
 		}
 
-		const elementNode = node as HTMLElement;
-
-		const attributes = elementNode.attributes;
-		const localName = elementNode.localName as keyof JSX.IntrinsicElements;
-
 		const props: Record< string, any > = {};
-		const children: Array< TreeWalkerReturn > = [];
-		const directives: Array<
-			[ name: string, namespace: string | null, value: unknown ]
-		> = [];
+		const children = [];
+		const directives = [];
 		let ignore = false;
 		let island = false;
 
@@ -100,14 +84,14 @@ export function toVdom( root: Node ): [ string | VNode | null, Node | null ] {
 						.exec( attributes[ i ].value )
 						?.slice( 1 ) ?? [ null, attributes[ i ].value ];
 					try {
-						value = JSON.parse( value as string );
+						value = JSON.parse( value );
 					} catch ( e ) {}
 					if ( n === islandAttr ) {
 						island = true;
 						namespaces.push(
 							typeof value === 'string'
 								? value
-								: ( value as any )?.namespace ?? null
+								: value?.namespace ?? null
 						);
 					} else {
 						directives.push( [ n, ns, value ] );
@@ -121,16 +105,15 @@ export function toVdom( root: Node ): [ string | VNode | null, Node | null ] {
 
 		if ( ignore && ! island ) {
 			return [
-				h< any, any >( localName, {
+				h( localName, {
 					...props,
-					innerHTML: elementNode.innerHTML,
+					innerHTML: node.innerHTML,
 					__directives: { ignore: true },
 				} ),
-				null,
 			];
 		}
 		if ( island ) {
-			hydratedIslands.add( elementNode );
+			hydratedIslands.add( node );
 		}
 
 		if ( directives.length ) {
@@ -156,11 +139,10 @@ export function toVdom( root: Node ): [ string | VNode | null, Node | null ] {
 			);
 		}
 
-		// @ts-expect-error Fixed in upcoming preact release https://github.com/preactjs/preact/pull/4334
 		if ( localName === 'template' ) {
-			props.content = [
-				...( elementNode as HTMLTemplateElement ).content.childNodes,
-			].map( ( childNode ) => toVdom( childNode ) );
+			props.content = [ ...node.content.childNodes ].map( ( childNode ) =>
+				toVdom( childNode )
+			);
 		} else {
 			let child = treeWalker.firstChild();
 			if ( child ) {
@@ -180,7 +162,7 @@ export function toVdom( root: Node ): [ string | VNode | null, Node | null ] {
 			namespaces.pop();
 		}
 
-		return [ h( localName, props, children ), null ];
+		return [ h( localName, props, children ) ];
 	}
 
 	return walk( treeWalker.currentNode );

From 4d79587cc034d0764d8be8e0715ecab32708d71a Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 15 May 2024 18:42:42 +0200
Subject: [PATCH 17/23] Better

---
 packages/interactivity/src/vdom.ts | 86 ++++++++++++++++++------------
 1 file changed, 53 insertions(+), 33 deletions(-)

diff --git a/packages/interactivity/src/vdom.ts b/packages/interactivity/src/vdom.ts
index 78f6d7032613a5..86706e541b9561 100644
--- a/packages/interactivity/src/vdom.ts
+++ b/packages/interactivity/src/vdom.ts
@@ -1,7 +1,7 @@
 /**
  * External dependencies
  */
-import { h } from 'preact';
+import { h, type ComponentChild, type JSX } from 'preact';
 /**
  * Internal dependencies
  */
@@ -11,7 +11,7 @@ import { warn } from './utils/warn';
 const ignoreAttr = `data-${ p }-ignore`;
 const islandAttr = `data-${ p }-interactive`;
 const fullPrefix = `data-${ p }-`;
-const namespaces = [];
+const namespaces: Array< string | null > = [];
 const currentNamespace = () => namespaces[ namespaces.length - 1 ] ?? null;
 
 // Regular expression for directive parsing.
@@ -39,81 +39,100 @@ export const hydratedIslands = new WeakSet();
 /**
  * Recursive function that transforms a DOM tree into vDOM.
  *
- * @param {Node} root The root element or node to start traversing on.
- * @return {import('preact').VNode[]} The resulting vDOM tree.
+ * @param root The root element or node to start traversing on.
+ * @return The resulting vDOM tree.
  */
-export function toVdom( root ) {
+export function toVdom( root: Node ): Array< ComponentChild > {
 	const treeWalker = document.createTreeWalker(
 		root,
-		205 // ELEMENT + TEXT + COMMENT + CDATA_SECTION + PROCESSING_INSTRUCTION
+		205 // TEXT + CDATA_SECTION + COMMENT + PROCESSING_INSTRUCTION + ELEMENT
 	);
 
-	function walk( node ) {
-		const { attributes, nodeType, localName } = node;
+	function walk(
+		node: Node
+	): [ ComponentChild ] | [ ComponentChild, Node | null ] {
+		const { nodeType } = node;
 
+		// TEXT_NODE (3)
 		if ( nodeType === 3 ) {
-			return [ node.data ];
+			return [ ( node as Text ).data ];
 		}
+
+		// CDATA_SECTION_NODE (4)
 		if ( nodeType === 4 ) {
 			const next = treeWalker.nextSibling();
-			node.replaceWith( new window.Text( node.nodeValue ) );
+			( node as CDATASection ).replaceWith(
+				new window.Text( ( node as CDATASection ).nodeValue ?? '' )
+			);
 			return [ node.nodeValue, next ];
 		}
+
+		// COMMENT_NODE (8) || PROCESSING_INSTRUCTION_NODE (7)
 		if ( nodeType === 8 || nodeType === 7 ) {
 			const next = treeWalker.nextSibling();
-			node.remove();
+			( node as Comment | ProcessingInstruction ).remove();
 			return [ null, next ];
 		}
 
+		const elementNode = node as HTMLElement;
+		const { attributes } = elementNode;
+		const localName = elementNode.localName as keyof JSX.IntrinsicElements;
+
 		const props: Record< string, any > = {};
-		const children = [];
-		const directives = [];
+		const children: Array< ComponentChild > = [];
+		const directives: Array<
+			[ name: string, namespace: string | null, value: unknown ]
+		> = [];
 		let ignore = false;
 		let island = false;
 
 		for ( let i = 0; i < attributes.length; i++ ) {
-			const n = attributes[ i ].name;
+			const attributeName = attributes[ i ].name;
 			if (
-				n[ fullPrefix.length ] &&
-				n.slice( 0, fullPrefix.length ) === fullPrefix
+				attributeName[ fullPrefix.length ] &&
+				attributeName.slice( 0, fullPrefix.length ) === fullPrefix
 			) {
-				if ( n === ignoreAttr ) {
+				if ( attributeName === ignoreAttr ) {
 					ignore = true;
 				} else {
-					let [ ns, value ] = nsPathRegExp
+					const [ ns, value ] = nsPathRegExp
 						.exec( attributes[ i ].value )
 						?.slice( 1 ) ?? [ null, attributes[ i ].value ];
+					let parsedValue: Record< string, unknown > | null = null;
 					try {
-						value = JSON.parse( value );
+						parsedValue = value ? JSON.parse( value ) : null;
 					} catch ( e ) {}
-					if ( n === islandAttr ) {
+					if ( attributeName === islandAttr ) {
 						island = true;
-						namespaces.push(
-							typeof value === 'string'
+						const namespace =
+							// eslint-disable-next-line no-nested-ternary
+							typeof parsedValue?.namespace === 'string'
+								? parsedValue.namespace
+								: typeof value === 'string'
 								? value
-								: value?.namespace ?? null
-						);
+								: null;
+						namespaces.push( namespace );
 					} else {
-						directives.push( [ n, ns, value ] );
+						directives.push( [ attributeName, ns, value ] );
 					}
 				}
-			} else if ( n === 'ref' ) {
+			} else if ( attributeName === 'ref' ) {
 				continue;
 			}
-			props[ n ] = attributes[ i ].value;
+			props[ attributeName ] = attributes[ i ].value;
 		}
 
 		if ( ignore && ! island ) {
 			return [
-				h( localName, {
+				h< any, any >( localName, {
 					...props,
-					innerHTML: node.innerHTML,
+					innerHTML: elementNode.innerHTML,
 					__directives: { ignore: true },
 				} ),
 			];
 		}
 		if ( island ) {
-			hydratedIslands.add( node );
+			hydratedIslands.add( elementNode );
 		}
 
 		if ( directives.length ) {
@@ -139,10 +158,11 @@ export function toVdom( root ) {
 			);
 		}
 
+		// @ts-expect-error Fixed in upcoming preact release https://github.com/preactjs/preact/pull/4334
 		if ( localName === 'template' ) {
-			props.content = [ ...node.content.childNodes ].map( ( childNode ) =>
-				toVdom( childNode )
-			);
+			props.content = [
+				...( elementNode as HTMLTemplateElement ).content.childNodes,
+			].map( ( childNode ) => toVdom( childNode ) );
 		} else {
 			let child = treeWalker.firstChild();
 			if ( child ) {

From 982606e2cb8b93378817d5a77587f3881966124e Mon Sep 17 00:00:00 2001
From: Carlos Bravo <carlos.bravo@automattic.com>
Date: Wed, 15 May 2024 18:53:43 +0200
Subject: [PATCH 18/23] Update changelog

---
 packages/interactivity/CHANGELOG.md | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/interactivity/CHANGELOG.md b/packages/interactivity/CHANGELOG.md
index fc22086bef443a..4c54801c0210d5 100644
--- a/packages/interactivity/CHANGELOG.md
+++ b/packages/interactivity/CHANGELOG.md
@@ -2,10 +2,13 @@
 
 ## Unreleased
 
+### Enhancements
+
+-   Strict type checking. ([#59865] (https://github.com/WordPress/gutenberg/pull/59865/))
+
 ### Bug Fixes
 
 -	Allow multiple event handlers for the same type with `data-wp-on-document` and `data-wp-on-window`. ([#61009](https://github.com/WordPress/gutenberg/pull/61009))
-
 -	Prevent wrong written directives from killing the runtime ([#61249](https://github.com/WordPress/gutenberg/pull/61249))
 -	Prevent empty namespace or different namespaces from killing the runtime ([#61409](https://github.com/WordPress/gutenberg/pull/61409))
 

From dbf231aae35054d962a8aa5b8293f19130c95857 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 15 May 2024 19:32:56 +0200
Subject: [PATCH 19/23] Fix namespace regression, use named groups

---
 packages/interactivity/src/vdom.ts | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/packages/interactivity/src/vdom.ts b/packages/interactivity/src/vdom.ts
index 86706e541b9561..4933682749fb90 100644
--- a/packages/interactivity/src/vdom.ts
+++ b/packages/interactivity/src/vdom.ts
@@ -32,7 +32,7 @@ const directiveParser = new RegExp(
 // the reference, separated by `::`, like `some-namespace::state.somePath`.
 // Namespaces can contain any alphanumeric characters, hyphens, underscores or
 // forward slashes. References don't have any restrictions.
-const nsPathRegExp = /^([\w-_\/]+)::(.+)$/;
+const nsPathRegExp = /^(?:(?<namespace>[\w_\/-]+)::)(?<value>.+)$/;
 
 export const hydratedIslands = new WeakSet();
 
@@ -95,25 +95,27 @@ export function toVdom( root: Node ): Array< ComponentChild > {
 				if ( attributeName === ignoreAttr ) {
 					ignore = true;
 				} else {
-					const [ ns, value ] = nsPathRegExp
-						.exec( attributes[ i ].value )
-						?.slice( 1 ) ?? [ null, attributes[ i ].value ];
-					let parsedValue: Record< string, unknown > | null = null;
+					const regexResult = nsPathRegExp.exec(
+						attributes[ i ].value
+					)?.groups;
+					const namespace = regexResult?.nameSpace ?? null;
+					let value: any =
+						regexResult?.value ?? attributes[ i ].value;
 					try {
-						parsedValue = value ? JSON.parse( value ) : null;
+						value = value && JSON.parse( value );
 					} catch ( e ) {}
 					if ( attributeName === islandAttr ) {
 						island = true;
-						const namespace =
+						const islandNamespace =
 							// eslint-disable-next-line no-nested-ternary
-							typeof parsedValue?.namespace === 'string'
-								? parsedValue.namespace
-								: typeof value === 'string'
+							typeof value === 'string'
 								? value
+								: typeof value?.namespace === 'string'
+								? value.namespace
 								: null;
-						namespaces.push( namespace );
+						namespaces.push( islandNamespace );
 					} else {
-						directives.push( [ attributeName, ns, value ] );
+						directives.push( [ attributeName, namespace, value ] );
 					}
 				}
 			} else if ( attributeName === 'ref' ) {

From 6dd3b341ad6210a6ca53d8a5b267690b72be89db Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 15 May 2024 19:33:58 +0200
Subject: [PATCH 20/23] Remove redundant group from ns regex

---
 packages/interactivity/src/vdom.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/interactivity/src/vdom.ts b/packages/interactivity/src/vdom.ts
index 4933682749fb90..1466d478b97c41 100644
--- a/packages/interactivity/src/vdom.ts
+++ b/packages/interactivity/src/vdom.ts
@@ -32,7 +32,7 @@ const directiveParser = new RegExp(
 // the reference, separated by `::`, like `some-namespace::state.somePath`.
 // Namespaces can contain any alphanumeric characters, hyphens, underscores or
 // forward slashes. References don't have any restrictions.
-const nsPathRegExp = /^(?:(?<namespace>[\w_\/-]+)::)(?<value>.+)$/;
+const nsPathRegExp = /^(?<namespace>[\w_\/-]+)::(?<value>.+)$/;
 
 export const hydratedIslands = new WeakSet();
 

From b728830f6e91ee0308b4eab6ed0576f26c6d91d1 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 15 May 2024 19:36:51 +0200
Subject: [PATCH 21/23] Update packages/interactivity/CHANGELOG.md

---
 packages/interactivity/CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/interactivity/CHANGELOG.md b/packages/interactivity/CHANGELOG.md
index 4c54801c0210d5..01097504d7064a 100644
--- a/packages/interactivity/CHANGELOG.md
+++ b/packages/interactivity/CHANGELOG.md
@@ -4,7 +4,7 @@
 
 ### Enhancements
 
--   Strict type checking. ([#59865] (https://github.com/WordPress/gutenberg/pull/59865/))
+-   Strict type checking: fix some missing nulls in published types ([#59865](https://github.com/WordPress/gutenberg/pull/59865/)).
 
 ### Bug Fixes
 

From 1f53865105430ad5811456d957184f084a92a4f2 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 15 May 2024 19:43:21 +0200
Subject: [PATCH 22/23] Still learning to type

---
 packages/interactivity/src/vdom.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/interactivity/src/vdom.ts b/packages/interactivity/src/vdom.ts
index 1466d478b97c41..1af48c3c0c7ca9 100644
--- a/packages/interactivity/src/vdom.ts
+++ b/packages/interactivity/src/vdom.ts
@@ -98,7 +98,7 @@ export function toVdom( root: Node ): Array< ComponentChild > {
 					const regexResult = nsPathRegExp.exec(
 						attributes[ i ].value
 					)?.groups;
-					const namespace = regexResult?.nameSpace ?? null;
+					const namespace = regexResult?.namespace ?? null;
 					let value: any =
 						regexResult?.value ?? attributes[ i ].value;
 					try {

From 1db22687abbc9b21e1e81289925841081278b6f7 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Wed, 15 May 2024 19:55:02 +0200
Subject: [PATCH 23/23] Better variable naming

---
 packages/interactivity/src/vdom.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/interactivity/src/vdom.ts b/packages/interactivity/src/vdom.ts
index 1af48c3c0c7ca9..d5238cde49d8e7 100644
--- a/packages/interactivity/src/vdom.ts
+++ b/packages/interactivity/src/vdom.ts
@@ -95,12 +95,12 @@ export function toVdom( root: Node ): Array< ComponentChild > {
 				if ( attributeName === ignoreAttr ) {
 					ignore = true;
 				} else {
-					const regexResult = nsPathRegExp.exec(
+					const regexCaptureGroups = nsPathRegExp.exec(
 						attributes[ i ].value
 					)?.groups;
-					const namespace = regexResult?.namespace ?? null;
+					const namespace = regexCaptureGroups?.namespace ?? null;
 					let value: any =
-						regexResult?.value ?? attributes[ i ].value;
+						regexCaptureGroups?.value ?? attributes[ i ].value;
 					try {
 						value = value && JSON.parse( value );
 					} catch ( e ) {}