chore: improve type safety (#40)

Co-authored-by: Milan Burda <miburda@microsoft.com>

src/main/objects-registry.ts

@@ -19,7 +19,7 @@ class ObjectsRegistry {
 
   // Register a new object and return its assigned ID. If the object is already
   // registered then the already assigned ID would be returned.
-  add (webContents: WebContents, contextId: string, obj: any) {
+  add (webContents: WebContents, contextId: string, obj: any): number {
     // Get or assign an ID to the object.
     const id = this.saveToStorage(obj)
 
@@ -41,15 +41,15 @@ class ObjectsRegistry {
   }
 
   // Get an object according to its ID.
-  get (id: number) {
+  get (id: number): any {
     const pointer = this.storage[id]
     if (pointer != null) return pointer.object
   }
 
   // Dereference an object according to its ID.
   // Note that an object may be double-freed (cleared when page is reloaded, and
   // then garbage collected in old page).
-  remove (webContents: WebContents, contextId: string, id: number) {
+  remove (webContents: WebContents, contextId: string, id: number): void {
     const ownerKey = getOwnerKey(webContents, contextId)
     const owner = this.owners[ownerKey]
     if (owner && owner.has(id)) {
@@ -69,7 +69,7 @@ class ObjectsRegistry {
   }
 
   // Clear all references to objects refrenced by the WebContents.
-  clear (webContents: WebContents, contextId: string) {
+  clear (webContents: WebContents, contextId: string): void {
     const ownerKey = getOwnerKey(webContents, contextId)
     const owner = this.owners[ownerKey]
     if (!owner) return
@@ -79,8 +79,8 @@ class ObjectsRegistry {
     delete this.owners[ownerKey]
   }
 
-  // Private: Saves the object into storage and assigns an ID for it.
-  saveToStorage (object: any) {
+  // Saves the object into storage and assigns an ID for it.
+  private saveToStorage (object: any): number {
     let id = this.electronIds.get(object)
     if (!id) {
       id = ++this.nextId
@@ -93,8 +93,8 @@ class ObjectsRegistry {
     return id
   }
 
-  // Private: Dereference the object from store.
-  dereference (id: number) {
+  // Dereference the object from store.
+  private dereference (id: number): void {
     const pointer = this.storage[id]
     if (pointer == null) {
       return
@@ -106,8 +106,8 @@ class ObjectsRegistry {
     }
   }
 
-  // Private: Clear the storage when renderer process is destroyed.
-  registerDeleteListener (webContents: WebContents, contextId: string) {
+  // Clear the storage when renderer process is destroyed.
+  private registerDeleteListener (webContents: WebContents, contextId: string): void {
     // contextId => ${processHostId}-${contextCount}
     const processHostId = contextId.split('-')[0]
     const listener = (_: any, deletedProcessHostId: string) => {

src/renderer/callbacks-registry.ts

@@ -5,18 +5,20 @@ export class CallbacksRegistry {
   private callbackIds = new WeakMap<Function, number>();
   private locationInfo = new WeakMap<Function, string>();
 
-  add (callback: Function) {
+  add (callback: Function): number {
     // The callback is already added.
     let id = this.callbackIds.get(callback);
     if (id != null) return id
 
     id = this.nextId += 1
+    this.callbacks[id] = callback
+    this.callbackIds.set(callback, id);
 
     // Capture the location of the function and put it in the ID string,
     // so that release errors can be tracked down easily.
     const regexp = /at (.*)/gi
     const stackString = (new Error()).stack
-    if (!stackString) return
+    if (!stackString) return id;
 
     let filenameAndLine: string;
     let match
@@ -34,25 +36,23 @@ export class CallbacksRegistry {
       break
     }
 
-    this.callbacks[id] = callback
-    this.callbackIds.set(callback, id);
     this.locationInfo.set(callback, filenameAndLine!);
     return id
   }
 
-  get (id: number) {
+  get (id: number): Function {
     return this.callbacks[id] || function () {}
   }
 
-  getLocation (callback: Function) {
+  getLocation (callback: Function): string | undefined {
     return this.locationInfo.get(callback);
   }
 
-  apply (id: number, ...args: any[]) {
+  apply (id: number, ...args: any[]): any {
     return this.get(id).apply(global, ...args)
   }
 
-  remove (id: number) {
+  remove (id: number): void {
     const callback = this.callbacks[id]
     if (callback) {
       this.callbackIds.delete(callback);

src/renderer/remote.ts

@@ -50,8 +50,8 @@ process.on('exit', () => {
 const IS_REMOTE_PROXY = Symbol('is-remote-proxy')
 
 // Convert the arguments object into an array of meta data.
-function wrapArgs (args: any[], visited = new Set()): any {
-  const valueToMeta = (value: any): any => {
+function wrapArgs (args: any[], visited = new Set()): MetaTypeFromRenderer[] {
+  const valueToMeta = (value: any): MetaTypeFromRenderer => {
     // Check for circular reference.
     if (visited.has(value)) {
       return {
@@ -64,7 +64,7 @@ function wrapArgs (args: any[], visited = new Set()): any {
       return { type: 'nativeimage', value: serialize(value) }
     } else if (Array.isArray(value)) {
       visited.add(value)
-      const meta = {
+      const meta: MetaTypeFromRenderer = {
         type: 'array',
         value: wrapArgs(value, visited)
       }
@@ -91,7 +91,7 @@ function wrapArgs (args: any[], visited = new Set()): any {
       } else if (electronIds.has(value)) {
         return {
           type: 'remote-object',
-          id: electronIds.get(value)
+          id: electronIds.get(value)!
         }
       }
 
@@ -118,7 +118,7 @@ function wrapArgs (args: any[], visited = new Set()): any {
       return {
         type: 'function',
         id: callbacksRegistry.add(value),
-        location: callbacksRegistry.getLocation(value),
+        location: callbacksRegistry.getLocation(value)!,
         length: value.length
       }
     } else {