Switch to Node.js 16 LTS, upgrade TypeScript, ESLint, and other dependencies (#395)

* Upgrade TypeScript, ESLint, and other dependencies

This also cleans up various other files where newer ESLint rules complained

* Set CI and CD to use Node.js version 16

* Small tweak

* Fix CD version printing

* Add nvm version for Cloudflare Pages

frontend/src/utilities/panic-proxy.ts

@@ -17,7 +17,7 @@ export function panicProxy<T extends object>(module: T): T {
 			return function (...args: any) {
 				let result;
 				try {
-					// @ts-expect-error
+					// @ts-expect-error TypeScript does not know what `this` is, since it should be able to be anything
 					result = targetValue.apply(this, args);
 				} catch (err: any) {
 					// Suppress `unreachable` WebAssembly.RuntimeError exceptions

frontend/src/utilities/response-handler.ts

@@ -98,16 +98,25 @@ function parseResponse(responseType: string, data: any): Response {
 }
 
 export type Response =
+	| DocumentChanged
+	| DisplayFolderTreeStructure
 	| SetActiveTool
+	| SetActiveDocument
+	| UpdateOpenDocumentsList
 	| UpdateCanvas
 	| UpdateScrollbars
 	| UpdateRulers
 	| UpdateLayer
-	| DocumentChanged
-	| DisplayFolderTreeStructure
-	| UpdateWorkingColors
 	| SetCanvasZoom
-	| SetCanvasRotation;
+	| SetCanvasRotation
+	| ExportDocument
+	| SaveDocument
+	| OpenDocumentBrowse
+	| UpdateWorkingColors
+	| DisplayError
+	| DisplayPanic
+	| DisplayConfirmationToCloseDocument
+	| DisplayConfirmationToCloseAllDocuments;
 
 export interface UpdateOpenDocumentsList {
 	open_documents: Array<string>;
@@ -191,7 +200,9 @@ function newDisplayConfirmationToCloseDocument(input: any): DisplayConfirmationT
 	};
 }
 
-function newDisplayConfirmationToCloseAllDocuments(_input: any): {} {
+export type DisplayConfirmationToCloseAllDocuments = Record<string, never>;
+
+function newDisplayConfirmationToCloseAllDocuments(_input: any): DisplayConfirmationToCloseAllDocuments {
 	return {};
 }
 
@@ -252,12 +263,12 @@ function newSaveDocument(input: any): SaveDocument {
 	};
 }
 
-export type OpenDocumentBrowse = {};
+export type OpenDocumentBrowse = Record<string, never>;
 function newOpenDocumentBrowse(_: any): OpenDocumentBrowse {
 	return {};
 }
 
-export type DocumentChanged = {};
+export type DocumentChanged = Record<string, never>;
 function newDocumentChanged(_: any): DocumentChanged {
 	return {};
 }