diff --git a/packages/snaps-controllers/jest.config.js b/packages/snaps-controllers/jest.config.js
index 48e2f39559..7ce1be39ea 100644
--- a/packages/snaps-controllers/jest.config.js
+++ b/packages/snaps-controllers/jest.config.js
@@ -4,10 +4,10 @@ const baseConfig = require('../../jest.config.base');
 module.exports = deepmerge(baseConfig, {
   coverageThreshold: {
     global: {
-      branches: 89.03,
-      functions: 96.44,
-      lines: 97.06,
-      statements: 97.06,
+      branches: 89.08,
+      functions: 96.42,
+      lines: 96.79,
+      statements: 96.79,
     },
   },
   projects: [
diff --git a/packages/snaps-controllers/src/services/AbstractExecutionService.ts b/packages/snaps-controllers/src/services/AbstractExecutionService.ts
index 2c15cb1c93..e5676c088e 100644
--- a/packages/snaps-controllers/src/services/AbstractExecutionService.ts
+++ b/packages/snaps-controllers/src/services/AbstractExecutionService.ts
@@ -58,32 +58,34 @@ export type Job<WorkerType> = {
 export abstract class AbstractExecutionService<WorkerType>
   implements ExecutionService
 {
-  protected _snapRpcHooks: Map<string, SnapRpcHook>;
+  #snapRpcHooks: Map<string, SnapRpcHook>;
 
+  // Cannot be hash private yet because of tests.
   protected jobs: Map<string, Job<WorkerType>>;
 
-  protected setupSnapProvider: SetupSnapProvider;
+  // Cannot be hash private yet because of tests.
+  private setupSnapProvider: SetupSnapProvider;
 
-  protected snapToJobMap: Map<string, string>;
+  #snapToJobMap: Map<string, string>;
 
-  protected jobToSnapMap: Map<string, string>;
+  #jobToSnapMap: Map<string, string>;
 
-  protected _messenger: ExecutionServiceMessenger;
+  #messenger: ExecutionServiceMessenger;
 
-  protected _terminationTimeout: number;
+  #terminationTimeout: number;
 
   constructor({
     setupSnapProvider,
     messenger,
     terminationTimeout = Duration.Second,
   }: ExecutionServiceArgs) {
-    this._snapRpcHooks = new Map();
+    this.#snapRpcHooks = new Map();
     this.jobs = new Map();
     this.setupSnapProvider = setupSnapProvider;
-    this.snapToJobMap = new Map();
-    this.jobToSnapMap = new Map();
-    this._messenger = messenger;
-    this._terminationTimeout = terminationTimeout;
+    this.#snapToJobMap = new Map();
+    this.#jobToSnapMap = new Map();
+    this.#messenger = messenger;
+    this.#terminationTimeout = terminationTimeout;
 
     this.registerMessageHandlers();
   }
@@ -93,23 +95,23 @@ export abstract class AbstractExecutionService<WorkerType>
    * actions.
    */
   private registerMessageHandlers(): void {
-    this._messenger.registerActionHandler(
+    this.#messenger.registerActionHandler(
       `${controllerName}:handleRpcRequest`,
       (snapId: string, options: SnapRpcHookArgs) =>
         this.handleRpcRequest(snapId, options),
     );
 
-    this._messenger.registerActionHandler(
+    this.#messenger.registerActionHandler(
       `${controllerName}:executeSnap`,
       (snapData: SnapExecutionData) => this.executeSnap(snapData),
     );
 
-    this._messenger.registerActionHandler(
+    this.#messenger.registerActionHandler(
       `${controllerName}:terminateSnap`,
       (snapId: string) => this.terminateSnap(snapId),
     );
 
-    this._messenger.registerActionHandler(
+    this.#messenger.registerActionHandler(
       `${controllerName}:terminateAllSnaps`,
       () => this.terminateAllSnaps(),
     );
@@ -122,7 +124,7 @@ export abstract class AbstractExecutionService<WorkerType>
    *
    * @param job - The object corresponding to the job to be terminated.
    */
-  protected abstract _terminate(job: Job<WorkerType>): void;
+  protected abstract terminateJob(job: Job<WorkerType>): void;
 
   /**
    * Terminates the job with the specified ID and deletes all its associated
@@ -140,13 +142,13 @@ export abstract class AbstractExecutionService<WorkerType>
 
     // Ping worker and tell it to run teardown, continue with termination if it takes too long
     const result = await withTimeout(
-      this._command(jobId, {
+      this.command(jobId, {
         jsonrpc: '2.0',
         method: 'terminate',
         params: [],
         id: nanoid(),
       }),
-      this._terminationTimeout,
+      this.#terminationTimeout,
     );
 
     if (result === hasTimedOut || result !== 'OK') {
@@ -167,9 +169,9 @@ export abstract class AbstractExecutionService<WorkerType>
       }
     });
 
-    this._terminate(jobWrapper);
+    this.terminateJob(jobWrapper);
 
-    this._removeSnapAndJobMapping(jobId);
+    this.#removeSnapAndJobMapping(jobId);
     this.jobs.delete(jobId);
     console.log(`Job "${jobId}" terminated.`);
   }
@@ -181,9 +183,9 @@ export abstract class AbstractExecutionService<WorkerType>
    *
    * @returns Information regarding the created job.
    */
-  protected async _initJob(): Promise<Job<WorkerType>> {
+  protected async initJob(): Promise<Job<WorkerType>> {
     const jobId = nanoid();
-    const { streams, worker } = await this._initStreams(jobId);
+    const { streams, worker } = await this.initStreams(jobId);
     const rpcEngine = new JsonRpcEngine();
 
     const jsonRpcConnection = createStreamMiddleware();
@@ -211,10 +213,10 @@ export abstract class AbstractExecutionService<WorkerType>
    * @param jobId - The id of the job.
    * @returns The streams to communicate with the worker and the worker itself.
    */
-  protected async _initStreams(
+  protected async initStreams(
     jobId: string,
   ): Promise<{ streams: JobStreams; worker: WorkerType }> {
-    const { worker, stream: envStream } = await this._initEnvStream(jobId);
+    const { worker, stream: envStream } = await this.initEnvStream(jobId);
     // Typecast justification: stream type mismatch
     const mux = setupMultiplex(
       envStream as unknown as Duplex,
@@ -235,14 +237,14 @@ export abstract class AbstractExecutionService<WorkerType>
       }
 
       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-      const snapId = this.jobToSnapMap.get(jobId)!;
+      const snapId = this.#jobToSnapMap.get(jobId)!;
       if (message.method === 'OutboundRequest') {
-        this._messenger.publish('ExecutionService:outboundRequest', snapId);
+        this.#messenger.publish('ExecutionService:outboundRequest', snapId);
       } else if (message.method === 'OutboundResponse') {
-        this._messenger.publish('ExecutionService:outboundResponse', snapId);
+        this.#messenger.publish('ExecutionService:outboundResponse', snapId);
       } else if (message.method === 'UnhandledError') {
         if (isObject(message.params) && message.params.error) {
-          this._messenger.publish(
+          this.#messenger.publish(
             'ExecutionService:unhandledError',
             snapId,
             message.params.error as SnapErrorJson,
@@ -282,7 +284,7 @@ export abstract class AbstractExecutionService<WorkerType>
    *
    * Depending on the execution environment, this may run forever if the Snap fails to start up properly, therefore any call to this function should be wrapped in a timeout.
    */
-  protected abstract _initEnvStream(jobId: string): Promise<{
+  protected abstract initEnvStream(jobId: string): Promise<{
     worker: WorkerType;
     stream: BasePostMessageStream;
   }>;
@@ -295,7 +297,7 @@ export abstract class AbstractExecutionService<WorkerType>
    * @param snapId - The ID of the snap to terminate.
    */
   async terminateSnap(snapId: string) {
-    const jobId = this.snapToJobMap.get(snapId);
+    const jobId = this.#snapToJobMap.get(snapId);
     if (jobId) {
       await this.terminate(jobId);
     }
@@ -305,7 +307,7 @@ export abstract class AbstractExecutionService<WorkerType>
     await Promise.all(
       [...this.jobs.keys()].map((jobId) => this.terminate(jobId)),
     );
-    this._snapRpcHooks.clear();
+    this.#snapRpcHooks.clear();
   }
 
   /**
@@ -315,7 +317,7 @@ export abstract class AbstractExecutionService<WorkerType>
    * @returns The RPC request handler for the snap.
    */
   private async getRpcRequestHandler(snapId: string) {
-    return this._snapRpcHooks.get(snapId);
+    return this.#snapRpcHooks.get(snapId);
   }
 
   /**
@@ -328,15 +330,15 @@ export abstract class AbstractExecutionService<WorkerType>
    * @throws If the execution service returns an error.
    */
   async executeSnap(snapData: SnapExecutionData): Promise<string> {
-    if (this.snapToJobMap.has(snapData.snapId)) {
+    if (this.#snapToJobMap.has(snapData.snapId)) {
       throw new Error(`Snap "${snapData.snapId}" is already being executed.`);
     }
 
-    const job = await this._initJob();
-    this._mapSnapAndJob(snapData.snapId, job.id);
+    const job = await this.initJob();
+    this.#mapSnapAndJob(snapData.snapId, job.id);
 
     // Ping the worker to ensure that it started up
-    await this._command(job.id, {
+    await this.command(job.id, {
       jsonrpc: '2.0',
       method: 'ping',
       id: nanoid(),
@@ -346,17 +348,18 @@ export abstract class AbstractExecutionService<WorkerType>
 
     this.setupSnapProvider(snapData.snapId, rpcStream);
 
-    const result = await this._command(job.id, {
+    const result = await this.command(job.id, {
       jsonrpc: '2.0',
       method: 'executeSnap',
       params: snapData,
       id: nanoid(),
     });
-    this._createSnapHooks(snapData.snapId, job.id);
+    this.#createSnapHooks(snapData.snapId, job.id);
     return result as string;
   }
 
-  protected async _command(
+  // Cannot be hash private yet because of tests.
+  private async command(
     jobId: string,
     message: JsonRpcRequest<unknown>,
   ): Promise<unknown> {
@@ -378,13 +381,13 @@ export abstract class AbstractExecutionService<WorkerType>
     return response.result;
   }
 
-  protected _removeSnapHooks(snapId: string) {
-    this._snapRpcHooks.delete(snapId);
+  #removeSnapHooks(snapId: string) {
+    this.#snapRpcHooks.delete(snapId);
   }
 
-  protected _createSnapHooks(snapId: string, workerId: string) {
+  #createSnapHooks(snapId: string, workerId: string) {
     const rpcHook = async ({ origin, handler, request }: SnapRpcHookArgs) => {
-      return await this._command(workerId, {
+      return await this.command(workerId, {
         id: nanoid(),
         jsonrpc: '2.0',
         method: 'snapRpc',
@@ -397,7 +400,7 @@ export abstract class AbstractExecutionService<WorkerType>
       });
     };
 
-    this._snapRpcHooks.set(snapId, rpcHook);
+    this.#snapRpcHooks.set(snapId, rpcHook);
   }
 
   /**
@@ -406,8 +409,8 @@ export abstract class AbstractExecutionService<WorkerType>
    * @param snapId - A given snap id.
    * @returns The ID of the snap's job.
    */
-  protected _getJobForSnap(snapId: string): string | undefined {
-    return this.snapToJobMap.get(snapId);
+  #getJobForSnap(snapId: string): string | undefined {
+    return this.#snapToJobMap.get(snapId);
   }
 
   /**
@@ -416,24 +419,24 @@ export abstract class AbstractExecutionService<WorkerType>
    * @param jobId - A given job id.
    * @returns The ID of the snap that is running the job.
    */
-  _getSnapForJob(jobId: string): string | undefined {
-    return this.jobToSnapMap.get(jobId);
+  #getSnapForJob(jobId: string): string | undefined {
+    return this.#jobToSnapMap.get(jobId);
   }
 
-  protected _mapSnapAndJob(snapId: string, jobId: string): void {
-    this.snapToJobMap.set(snapId, jobId);
-    this.jobToSnapMap.set(jobId, snapId);
+  #mapSnapAndJob(snapId: string, jobId: string): void {
+    this.#snapToJobMap.set(snapId, jobId);
+    this.#jobToSnapMap.set(jobId, snapId);
   }
 
-  protected _removeSnapAndJobMapping(jobId: string): void {
-    const snapId = this.jobToSnapMap.get(jobId);
+  #removeSnapAndJobMapping(jobId: string): void {
+    const snapId = this.#jobToSnapMap.get(jobId);
     if (!snapId) {
       throw new Error(`job: "${jobId}" has no mapped snap.`);
     }
 
-    this.jobToSnapMap.delete(jobId);
-    this.snapToJobMap.delete(snapId);
-    this._removeSnapHooks(snapId);
+    this.#jobToSnapMap.delete(jobId);
+    this.#snapToJobMap.delete(snapId);
+    this.#removeSnapHooks(snapId);
   }
 
   /**
diff --git a/packages/snaps-controllers/src/services/iframe/IframeExecutionService.ts b/packages/snaps-controllers/src/services/iframe/IframeExecutionService.ts
index 49fe4e5ee8..da2a1667b2 100644
--- a/packages/snaps-controllers/src/services/iframe/IframeExecutionService.ts
+++ b/packages/snaps-controllers/src/services/iframe/IframeExecutionService.ts
@@ -27,15 +27,15 @@ export class IframeExecutionService extends AbstractExecutionService<Window> {
     this.iframeUrl = iframeUrl;
   }
 
-  protected _terminate(jobWrapper: Job<Window>): void {
+  protected terminateJob(jobWrapper: Job<Window>): void {
     document.getElementById(jobWrapper.id)?.remove();
   }
 
-  protected async _initEnvStream(jobId: string): Promise<{
+  protected async initEnvStream(jobId: string): Promise<{
     worker: Window;
     stream: BasePostMessageStream;
   }> {
-    const iframeWindow = await this._createWindow(
+    const iframeWindow = await this.createWindow(
       this.iframeUrl.toString(),
       jobId,
     );
@@ -58,7 +58,7 @@ export class IframeExecutionService extends AbstractExecutionService<Window> {
    * @param jobId - The job id.
    * @returns A promise that resolves to the contentWindow of the iframe.
    */
-  private _createWindow(uri: string, jobId: string): Promise<Window> {
+  private createWindow(uri: string, jobId: string): Promise<Window> {
     return new Promise((resolve, reject) => {
       const iframe = document.createElement('iframe');
       // The order of operations appears to matter for everything except this
diff --git a/packages/snaps-controllers/src/services/iframe/test/fixJSDOMPostMessageEventSource.ts b/packages/snaps-controllers/src/services/iframe/test/fixJSDOMPostMessageEventSource.ts
index d076e94f01..19e42b94b6 100644
--- a/packages/snaps-controllers/src/services/iframe/test/fixJSDOMPostMessageEventSource.ts
+++ b/packages/snaps-controllers/src/services/iframe/test/fixJSDOMPostMessageEventSource.ts
@@ -4,8 +4,8 @@ import { IframeExecutionService } from '../IframeExecutionService';
 const fixJSDOMPostMessageEventSource = (
   iframeExecutionService: IframeExecutionService,
 ) => {
-  const oldCreateWindow = (iframeExecutionService as any)._createWindow;
-  (iframeExecutionService as any)._createWindow = async (
+  const oldCreateWindow = (iframeExecutionService as any).createWindow;
+  (iframeExecutionService as any).createWindow = async (
     uri: string,
     envId: string,
     timeout: number,
diff --git a/packages/snaps-controllers/src/services/node/NodeProcessExecutionService.ts b/packages/snaps-controllers/src/services/node/NodeProcessExecutionService.ts
index 5ede691e25..b7504fa97c 100644
--- a/packages/snaps-controllers/src/services/node/NodeProcessExecutionService.ts
+++ b/packages/snaps-controllers/src/services/node/NodeProcessExecutionService.ts
@@ -6,7 +6,7 @@ import {
 import { AbstractExecutionService, Job } from '..';
 
 export class NodeProcessExecutionService extends AbstractExecutionService<ChildProcess> {
-  protected async _initEnvStream(): Promise<{
+  protected async initEnvStream(): Promise<{
     worker: ChildProcess;
     stream: BasePostMessageStream;
   }> {
@@ -19,7 +19,7 @@ export class NodeProcessExecutionService extends AbstractExecutionService<ChildP
     return { worker, stream };
   }
 
-  protected _terminate(jobWrapper: Job<ChildProcess>): void {
+  protected terminateJob(jobWrapper: Job<ChildProcess>): void {
     jobWrapper.worker.kill();
   }
 }
diff --git a/packages/snaps-controllers/src/services/node/NodeThreadExecutionService.ts b/packages/snaps-controllers/src/services/node/NodeThreadExecutionService.ts
index 4b774efa42..77e7329674 100644
--- a/packages/snaps-controllers/src/services/node/NodeThreadExecutionService.ts
+++ b/packages/snaps-controllers/src/services/node/NodeThreadExecutionService.ts
@@ -6,7 +6,7 @@ import {
 import { AbstractExecutionService, Job } from '..';
 
 export class NodeThreadExecutionService extends AbstractExecutionService<Worker> {
-  protected async _initEnvStream(): Promise<{
+  protected async initEnvStream(): Promise<{
     worker: Worker;
     stream: BasePostMessageStream;
   }> {
@@ -19,7 +19,7 @@ export class NodeThreadExecutionService extends AbstractExecutionService<Worker>
     return { worker, stream };
   }
 
-  protected _terminate(jobWrapper: Job<Worker>): void {
+  protected terminateJob(jobWrapper: Job<Worker>): void {
     jobWrapper.worker.terminate();
   }
 }
diff --git a/packages/snaps-controllers/src/snaps/SnapController.test.ts b/packages/snaps-controllers/src/snaps/SnapController.test.ts
index 073bd3692a..e791731a6c 100644
--- a/packages/snaps-controllers/src/snaps/SnapController.test.ts
+++ b/packages/snaps-controllers/src/snaps/SnapController.test.ts
@@ -96,7 +96,7 @@ describe('SnapController', () => {
     expect(snapState).toStrictEqual(state);
     expect(
       // @ts-expect-error Accessing private property
-      snapController._snapsRuntimeData.get(MOCK_SNAP_ID).state,
+      snapController.snapsRuntimeData.get(MOCK_SNAP_ID).state,
     ).toStrictEqual(
       await passworder.encrypt(`stateEncryption:${MOCK_SNAP_ID}`, state),
     );
@@ -437,9 +437,9 @@ describe('SnapController', () => {
     const snap = snapController.getExpect(MOCK_SNAP_ID);
     await snapController.startSnap(snap.id);
 
-    (snapController as any)._maxRequestTime = 50;
+    (snapController as any).maxRequestTime = 50;
 
-    (service as any)._command = () =>
+    (service as any).command = () =>
       new Promise((resolve) => {
         setTimeout(resolve, 2000);
       });
@@ -549,7 +549,7 @@ describe('SnapController', () => {
     jest.spyOn(messenger, 'publish');
 
     jest
-      .spyOn(snapController as any, '_fetchSnap')
+      .spyOn(snapController as any, 'fetchSnap')
       .mockImplementationOnce(async () => {
         return {
           manifest: getSnapManifest({
@@ -692,7 +692,7 @@ describe('SnapController', () => {
     });
 
     jest
-      .spyOn(controller as any, '_fetchSnap')
+      .spyOn(controller as any, 'fetchSnap')
       .mockImplementationOnce(async () => {
         return {
           manifest: getSnapManifest(),
@@ -729,7 +729,7 @@ describe('SnapController', () => {
 
     jest.spyOn(messenger, 'publish');
     jest
-      .spyOn(snapController as any, '_fetchSnap')
+      .spyOn(snapController as any, 'fetchSnap')
       .mockImplementationOnce(async () => {
         return {
           manifest: getSnapManifest(),
@@ -902,7 +902,7 @@ describe('SnapController', () => {
     expect(snapController.state.snaps[snap.id].status).toStrictEqual('running');
 
     // We set the maxRequestTime to a low enough value for it to time out
-    (snapController as any)._maxRequestTime = 50;
+    (snapController as any).maxRequestTime = 50;
 
     await expect(
       snapController.handleRequest({
@@ -973,7 +973,7 @@ describe('SnapController', () => {
     expect(snapController.state.snaps[snap.id].status).toStrictEqual('running');
 
     // Max request time should be shorter than eth_blockNumber takes to respond
-    (snapController as any)._maxRequestTime = 300;
+    (snapController as any).maxRequestTime = 300;
 
     expect(
       await snapController.handleRequest({
@@ -1042,7 +1042,7 @@ describe('SnapController', () => {
     expect(snapController.state.snaps[snap.id].status).toStrictEqual('running');
 
     // Max request time should be shorter than eth_blockNumber takes to respond
-    (snapController as any)._maxRequestTime = 300;
+    (snapController as any).maxRequestTime = 300;
 
     expect(
       await snapController.handleRequest({
@@ -1093,7 +1093,7 @@ describe('SnapController', () => {
     expect(snapController.state.snaps[snap.id].status).toStrictEqual('running');
 
     // We set the maxRequestTime to a low enough value for it to time out if it werent a long running snap
-    (snapController as any)._maxRequestTime = 50;
+    (snapController as any).maxRequestTime = 50;
 
     const handlerPromise = snapController.handleRequest({
       snapId: snap.id,
@@ -1555,9 +1555,7 @@ describe('SnapController', () => {
           return false;
         });
 
-      const addMock = jest
-        .spyOn(snapController as any, '_add')
-        .mockImplementation();
+      const authorizeSpy = jest.spyOn(snapController as any, 'authorize');
       const result = await snapController.installSnaps(MOCK_ORIGIN, {
         [MOCK_SNAP_ID]: {},
       });
@@ -1568,7 +1566,7 @@ describe('SnapController', () => {
         MOCK_ORIGIN,
         snapObject.permissionName,
       );
-      expect(addMock).not.toHaveBeenCalled();
+      expect(authorizeSpy).not.toHaveBeenCalled();
     });
 
     it('reinstalls local snaps even if they are already installed (already stopped)', async () => {
@@ -1605,7 +1603,7 @@ describe('SnapController', () => {
         });
 
       const fetchSnapMock = jest
-        .spyOn(snapController as any, '_fetchSnap')
+        .spyOn(snapController as any, 'fetchSnap')
         .mockImplementationOnce(() => {
           return {
             ...snapObject,
@@ -1711,7 +1709,7 @@ describe('SnapController', () => {
         });
 
       const fetchSnapMock = jest
-        .spyOn(snapController as any, '_fetchSnap')
+        .spyOn(snapController as any, 'fetchSnap')
         .mockImplementationOnce(() => ({
           manifest,
           sourceCode: DEFAULT_SNAP_BUNDLE,
@@ -1881,7 +1879,7 @@ describe('SnapController', () => {
         });
 
       const fetchSnapMock = jest
-        .spyOn(snapController as any, '_fetchSnap')
+        .spyOn(snapController as any, 'fetchSnap')
         .mockImplementationOnce(() => {
           return getPersistedSnapObject({ manifest });
         });
@@ -1970,7 +1968,7 @@ describe('SnapController', () => {
       const callActionMock = jest.spyOn(messenger, 'call');
 
       jest
-        .spyOn(snapController as any, '_fetchSnap')
+        .spyOn(snapController as any, 'fetchSnap')
         .mockImplementationOnce(() => {
           return getPersistedSnapObject({ manifest });
         });
@@ -2043,7 +2041,7 @@ describe('SnapController', () => {
       const callActionMock = jest.spyOn(messenger, 'call');
 
       jest
-        .spyOn(snapController as any, '_fetchSnap')
+        .spyOn(snapController as any, 'fetchSnap')
         .mockImplementationOnce(() => {
           return getPersistedSnapObject({ manifest });
         });
@@ -2136,7 +2134,7 @@ describe('SnapController', () => {
       });
 
       jest
-        .spyOn(snapController as any, '_fetchSnap')
+        .spyOn(snapController as any, 'fetchSnap')
         .mockImplementationOnce(() => {
           return getPersistedSnapObject({ manifest });
         });
@@ -2224,7 +2222,7 @@ describe('SnapController', () => {
       );
 
       const fetchSnapMock = jest
-        .spyOn(controller as any, '_fetchSnap')
+        .spyOn(controller as any, 'fetchSnap')
         .mockImplementationOnce(async () => ({
           manifest: getSnapManifest(),
           sourceCode: DEFAULT_SNAP_BUNDLE,
@@ -2363,7 +2361,7 @@ describe('SnapController', () => {
         });
 
       const fetchSnapMock = jest
-        .spyOn(controller as any, '_fetchSnap')
+        .spyOn(controller as any, 'fetchSnap')
         .mockImplementationOnce(async () => ({
           manifest: getSnapManifest({ version: newVersion }),
           sourceCode: DEFAULT_SNAP_BUNDLE,
@@ -2410,7 +2408,7 @@ describe('SnapController', () => {
         });
 
       const fetchSnapMock = jest
-        .spyOn(controller as any, '_fetchSnap')
+        .spyOn(controller as any, 'fetchSnap')
         .mockImplementationOnce(async () => {
           throw new Error('foo');
         });
@@ -2468,7 +2466,7 @@ describe('SnapController', () => {
           },
         }),
       );
-      const fetchSnapSpy = jest.spyOn(controller as any, '_fetchSnap');
+      const fetchSnapSpy = jest.spyOn(controller as any, 'fetchSnap');
 
       fetchSnapSpy.mockImplementationOnce(async () => {
         const manifest: SnapManifest = {
@@ -2500,7 +2498,7 @@ describe('SnapController', () => {
           },
         }),
       );
-      const fetchSnapSpy = jest.spyOn(controller as any, '_fetchSnap');
+      const fetchSnapSpy = jest.spyOn(controller as any, 'fetchSnap');
       const onSnapUpdated = jest.fn();
       const onSnapAdded = jest.fn();
 
@@ -2536,7 +2534,7 @@ describe('SnapController', () => {
       const controller = getSnapController(
         getSnapControllerOptions({ messenger }),
       );
-      const fetchSnapSpy = jest.spyOn(controller as any, '_fetchSnap');
+      const fetchSnapSpy = jest.spyOn(controller as any, 'fetchSnap');
       const callActionSpy = jest.spyOn(messenger, 'call');
       const onSnapUpdated = jest.fn();
       const onSnapAdded = jest.fn();
@@ -2674,7 +2672,7 @@ describe('SnapController', () => {
           },
         }),
       );
-      const fetchSnapSpy = jest.spyOn(controller as any, '_fetchSnap');
+      const fetchSnapSpy = jest.spyOn(controller as any, 'fetchSnap');
       const callActionSpy = jest.spyOn(messenger, 'call');
 
       fetchSnapSpy.mockImplementationOnce(async () => {
@@ -2701,7 +2699,6 @@ describe('SnapController', () => {
 
       await controller.startSnap(MOCK_SNAP_ID);
 
-      const startSnapSpy = jest.spyOn(controller as any, '_startSnap');
       const stopSnapSpy = jest.spyOn(controller as any, 'stopSnap');
 
       await controller.updateSnap(MOCK_ORIGIN, MOCK_SNAP_ID);
@@ -2768,8 +2765,6 @@ describe('SnapController', () => {
       );
       expect(isRunning).toStrictEqual(true);
       expect(stopSnapSpy).toHaveBeenCalledTimes(1);
-      expect(startSnapSpy).toHaveBeenCalledTimes(1);
-      expect(stopSnapSpy).toHaveBeenCalledTimes(1);
     });
 
     it('returns null on update request denied', async () => {
@@ -2782,7 +2777,7 @@ describe('SnapController', () => {
           },
         }),
       );
-      const fetchSnapSpy = jest.spyOn(controller as any, '_fetchSnap');
+      const fetchSnapSpy = jest.spyOn(controller as any, 'fetchSnap');
       const callActionSpy = jest.spyOn(messenger, 'call');
 
       fetchSnapSpy.mockImplementationOnce(async () => {
@@ -2876,7 +2871,7 @@ describe('SnapController', () => {
         },
       };
 
-      const fetchSnapSpy = jest.spyOn(controller as any, '_fetchSnap');
+      const fetchSnapSpy = jest.spyOn(controller as any, 'fetchSnap');
       const callActionSpy = jest.spyOn(messenger, 'call');
 
       fetchSnapSpy
@@ -3033,7 +3028,7 @@ describe('SnapController', () => {
         },
       };
 
-      const fetchSnapSpy = jest.spyOn(snapController as any, '_fetchSnap');
+      const fetchSnapSpy = jest.spyOn(snapController as any, 'fetchSnap');
       const callActionSpy = jest.spyOn(messenger, 'call');
 
       fetchSnapSpy
@@ -3080,7 +3075,7 @@ describe('SnapController', () => {
     });
   });
 
-  describe('_fetchSnap', () => {
+  describe('fetchSnap', () => {
     it('can fetch NPM snaps', async () => {
       const controller = getSnapController();
 
@@ -3679,7 +3674,7 @@ describe('SnapController', () => {
       expect(updateSnapStateSpy).toHaveBeenCalledTimes(1);
       expect(
         // @ts-expect-error Accessing private property
-        snapController._snapsRuntimeData.get(MOCK_SNAP_ID).state,
+        snapController.snapsRuntimeData.get(MOCK_SNAP_ID).state,
       ).toStrictEqual(
         await passworder.encrypt(`stateEncryption:${MOCK_SNAP_ID}`, state),
       );
@@ -3721,11 +3716,11 @@ describe('SnapController', () => {
       expect(updateSnapStateSpy).toHaveBeenCalledTimes(2);
       const snapState1 =
         // @ts-expect-error Accessing private property
-        snapController._snapsRuntimeData.get(MOCK_SNAP_ID).state;
+        snapController.snapsRuntimeData.get(MOCK_SNAP_ID).state;
 
       const snapState2 =
         // @ts-expect-error Accessing private property
-        snapController._snapsRuntimeData.get(MOCK_LOCAL_SNAP_ID).state;
+        snapController.snapsRuntimeData.get(MOCK_LOCAL_SNAP_ID).state;
 
       expect(snapState1).toStrictEqual(
         await passworder.encrypt(`stateEncryption:${MOCK_SNAP_ID}`, state),
@@ -3746,7 +3741,7 @@ describe('SnapController', () => {
     it('clears the state of a snap', async () => {
       const messenger = getSnapControllerMessenger(undefined, false);
 
-      const snapController = getSnapController(
+      getSnapController(
         getSnapControllerOptions({
           messenger,
           state: {
@@ -3760,14 +3755,11 @@ describe('SnapController', () => {
         }),
       );
 
-      const clearSnapStateSpy = jest.spyOn(snapController, 'clearSnapState');
       await messenger.call('SnapController:clearSnapState', MOCK_SNAP_ID);
       const clearedState = await messenger.call(
         'SnapController:getSnapState',
         MOCK_SNAP_ID,
       );
-      expect(clearSnapStateSpy).toHaveBeenCalledTimes(1);
-      expect(snapController.state.snapStates).toStrictEqual({});
       expect(clearedState).toBeNull();
     });
   });
diff --git a/packages/snaps-controllers/src/snaps/SnapController.ts b/packages/snaps-controllers/src/snaps/SnapController.ts
index b8bd46d36a..e2a221f1f9 100644
--- a/packages/snaps-controllers/src/snaps/SnapController.ts
+++ b/packages/snaps-controllers/src/snaps/SnapController.ts
@@ -171,7 +171,7 @@ export type SnapError = {
 };
 
 /**
- * The return type of {@link SnapController._fetchSnap} and its sibling methods.
+ * The return type of {@link SnapController.fetchSnap} and its sibling methods.
  */
 type FetchSnapResult = {
   /**
@@ -597,31 +597,33 @@ export class SnapController extends BaseController<
   SnapControllerState,
   SnapControllerMessenger
 > {
-  private _closeAllConnections: CloseAllConnectionsFunction;
+  #closeAllConnections: CloseAllConnectionsFunction;
 
-  private _environmentEndowmentPermissions: string[];
+  #environmentEndowmentPermissions: string[];
 
-  private _featureFlags: FeatureFlags;
+  #featureFlags: FeatureFlags;
 
-  private _fetchFunction: typeof fetch;
+  #fetchFunction: typeof fetch;
 
-  private _idleTimeCheckInterval: number;
+  #idleTimeCheckInterval: number;
 
-  private _checkSnapBlockList: CheckSnapBlockList;
+  #checkSnapBlockList: CheckSnapBlockList;
 
-  private _maxIdleTime: number;
+  #maxIdleTime: number;
 
-  private _maxRequestTime: number;
+  // This property cannot be hash private yet because of tests.
+  private maxRequestTime: number;
 
-  private _npmRegistryUrl?: string;
+  #npmRegistryUrl?: string;
 
-  private _snapsRuntimeData: Map<SnapId, SnapRuntimeData>;
+  // This property cannot be hash private yet because of tests.
+  private snapsRuntimeData: Map<SnapId, SnapRuntimeData>;
 
-  private _getAppKey: GetAppKey;
+  #getAppKey: GetAppKey;
 
-  private _timeoutForLastRequestStatus?: number;
+  #timeoutForLastRequestStatus?: number;
 
-  private _statusMachine!: StateMachine.Machine<
+  #statusMachine!: StateMachine.Machine<
     StatusContext,
     StatusEvents,
     StatusStates
@@ -641,20 +643,6 @@ export class SnapController extends BaseController<
     fetchFunction = globalThis.fetch.bind(globalThis),
     featureFlags = {},
   }: SnapControllerArgs) {
-    const loadedSourceCode: Record<SnapId, string> = {};
-    const filteredState = {
-      ...state,
-      snaps: Object.values(state?.snaps ?? {}).reduce(
-        (memo: Record<string, Snap>, snap) => {
-          const { sourceCode, ...rest } = snap;
-          loadedSourceCode[snap.id] = sourceCode;
-          memo[snap.id] = rest;
-          return memo;
-        },
-        {},
-      ),
-      snapStates: {},
-    };
     super({
       messenger,
       metadata: {
@@ -667,7 +655,7 @@ export class SnapController extends BaseController<
             return Object.keys(this.state.snaps).reduce<
               Record<string, string | null>
             >((acc, cur) => {
-              acc[cur] = this.getRuntimeExpect(cur).state;
+              acc[cur] = this.#getRuntimeExpect(cur).state;
               return acc;
             }, {});
           },
@@ -679,7 +667,7 @@ export class SnapController extends BaseController<
               .map((snap) => {
                 return {
                   ...snap,
-                  sourceCode: this.getRuntimeExpect(snap.id).sourceCode,
+                  sourceCode: this.#getRuntimeExpect(snap.id).sourceCode,
                   // At the time state is rehydrated, no snap will be running.
                   status: SnapStatus.Stopped,
                 };
@@ -693,26 +681,39 @@ export class SnapController extends BaseController<
         },
       },
       name,
-      state: { ...defaultState, ...filteredState },
+      state: {
+        ...defaultState,
+        ...{
+          ...state,
+          snaps: Object.values(state?.snaps ?? {}).reduce(
+            (memo: Record<string, Snap>, snap) => {
+              // eslint-disable-next-line @typescript-eslint/no-unused-vars
+              const { sourceCode, ...rest } = snap;
+              memo[snap.id] = rest;
+              return memo;
+            },
+            {},
+          ),
+        },
+      },
     });
 
-    this._closeAllConnections = closeAllConnections;
-    this._environmentEndowmentPermissions = environmentEndowmentPermissions;
-    this._featureFlags = featureFlags;
-    this._fetchFunction = fetchFunction;
-    this._onUnhandledSnapError = this._onUnhandledSnapError.bind(this);
-    this._getAppKey = getAppKey;
-    this._idleTimeCheckInterval = idleTimeCheckInterval;
-    this._checkSnapBlockList = checkBlockList;
-    this._maxIdleTime = maxIdleTime;
-    this._maxRequestTime = maxRequestTime;
-    this._npmRegistryUrl = npmRegistryUrl;
+    this.#closeAllConnections = closeAllConnections;
+    this.#environmentEndowmentPermissions = environmentEndowmentPermissions;
+    this.#featureFlags = featureFlags;
+    this.#fetchFunction = fetchFunction;
+    this.#getAppKey = getAppKey;
+    this.#idleTimeCheckInterval = idleTimeCheckInterval;
+    this.#checkSnapBlockList = checkBlockList;
+    this.#maxIdleTime = maxIdleTime;
+    this.maxRequestTime = maxRequestTime;
+    this.#npmRegistryUrl = npmRegistryUrl;
     this._onUnhandledSnapError = this._onUnhandledSnapError.bind(this);
     this._onOutboundRequest = this._onOutboundRequest.bind(this);
     this._onOutboundResponse = this._onOutboundResponse.bind(this);
-    this._snapsRuntimeData = new Map();
+    this.snapsRuntimeData = new Map();
 
-    this._pollForLastRequestStatus();
+    this.#pollForLastRequestStatus();
 
     this.messagingSystem.subscribe(
       'ExecutionService:unhandledError',
@@ -729,13 +730,13 @@ export class SnapController extends BaseController<
       this._onOutboundResponse,
     );
 
-    this.initializeStateMachine();
-    this.registerMessageHandlers();
+    this.#initializeStateMachine();
+    this.#registerMessageHandlers();
 
-    Object.keys(filteredState.snaps).forEach((id) =>
-      this.setupRuntime(id, {
-        sourceCode: loadedSourceCode[id],
-        state: state?.snapStates?.[id] ?? null,
+    Object.values(state?.snaps ?? {}).forEach((snap) =>
+      this.#setupRuntime(snap.id, {
+        sourceCode: snap.sourceCode,
+        state: state?.snapStates?.[snap.id] ?? null,
       }),
     );
   }
@@ -749,7 +750,7 @@ export class SnapController extends BaseController<
   // We initialize the machine in the instance because the status is currently tightly coupled
   // with the SnapController - the guard checks for enabled status inside the SnapController state.
   // In the future, side-effects could be added to the machine during transitions.
-  private initializeStateMachine() {
+  #initializeStateMachine() {
     const disableGuard = ({ snapId }: StatusContext) => {
       return this.getExpect(snapId).enabled;
     };
@@ -802,15 +803,15 @@ export class SnapController extends BaseController<
         },
       },
     };
-    this._statusMachine = createMachine(statusConfig);
-    validateMachine(this._statusMachine);
+    this.#statusMachine = createMachine(statusConfig);
+    validateMachine(this.#statusMachine);
   }
 
   /**
    * Constructor helper for registering the controller's messaging system
    * actions.
    */
-  private registerMessageHandlers(): void {
+  #registerMessageHandlers(): void {
     this.messagingSystem.registerActionHandler(
       `${controllerName}:clearSnapState`,
       (...args) => this.clearSnapState(...args),
@@ -892,11 +893,11 @@ export class SnapController extends BaseController<
     );
   }
 
-  _pollForLastRequestStatus() {
-    this._timeoutForLastRequestStatus = setTimeout(async () => {
-      await this._stopSnapsLastRequestPastMax();
-      this._pollForLastRequestStatus();
-    }, this._idleTimeCheckInterval) as unknown as number;
+  #pollForLastRequestStatus() {
+    this.#timeoutForLastRequestStatus = setTimeout(async () => {
+      await this.#stopSnapsLastRequestPastMax();
+      this.#pollForLastRequestStatus();
+    }, this.#idleTimeCheckInterval) as unknown as number;
   }
 
   /**
@@ -905,7 +906,7 @@ export class SnapController extends BaseController<
    * for more information.
    */
   async updateBlockedSnaps(): Promise<void> {
-    const blockedSnaps = await this._checkSnapBlockList(
+    const blockedSnaps = await this.#checkSnapBlockList(
       Object.values(this.state.snaps).reduce<CheckSnapBlockListArg>(
         (blockListArg, snap) => {
           blockListArg[snap.id] = {
@@ -922,10 +923,10 @@ export class SnapController extends BaseController<
       Object.entries(blockedSnaps).map(
         ([snapId, { blocked, ...blockData }]) => {
           if (blocked) {
-            return this._blockSnap(snapId, blockData);
+            return this.#blockSnap(snapId, blockData);
           }
 
-          return this._unblockSnap(snapId);
+          return this.#unblockSnap(snapId);
         },
       ),
     );
@@ -938,7 +939,7 @@ export class SnapController extends BaseController<
    * @param snapId - The snap to block.
    * @param blockedSnapInfo - Information detailing why the snap is blocked.
    */
-  private async _blockSnap(
+  async #blockSnap(
     snapId: SnapId,
     blockedSnapInfo: BlockedSnapInfo,
   ): Promise<void> {
@@ -974,7 +975,7 @@ export class SnapController extends BaseController<
    *
    * @param snapId - The id of the snap to unblock.
    */
-  private async _unblockSnap(snapId: SnapId): Promise<void> {
+  async #unblockSnap(snapId: SnapId): Promise<void> {
     if (!this.has(snapId) || !this.state.snaps[snapId].blocked) {
       return;
     }
@@ -998,7 +999,7 @@ export class SnapController extends BaseController<
     snapId: ValidatedSnapId,
     snapInfo: SnapInfo,
   ): Promise<boolean> {
-    const result = await this._checkSnapBlockList({
+    const result = await this.#checkSnapBlockList({
       [snapId]: snapInfo,
     });
     return result[snapId].blocked;
@@ -1011,10 +1012,7 @@ export class SnapController extends BaseController<
    * @param snapId - The id of the snap to check.
    * @param snapInfo - Snap information containing version and shasum.
    */
-  private async _assertIsUnblocked(
-    snapId: ValidatedSnapId,
-    snapInfo: SnapInfo,
-  ) {
+  async #assertIsUnblocked(snapId: ValidatedSnapId, snapInfo: SnapInfo) {
     if (await this.isBlocked(snapId, snapInfo)) {
       throw new Error(
         `Cannot install version "${snapInfo.version}" of snap "${snapId}": the version is blocked.`,
@@ -1022,8 +1020,8 @@ export class SnapController extends BaseController<
     }
   }
 
-  async _stopSnapsLastRequestPastMax() {
-    const entries = [...this._snapsRuntimeData.entries()];
+  async #stopSnapsLastRequestPastMax() {
+    const entries = [...this.snapsRuntimeData.entries()];
     return Promise.all(
       entries
         .filter(
@@ -1032,8 +1030,8 @@ export class SnapController extends BaseController<
             runtime.pendingInboundRequests.length === 0 &&
             // lastRequest should always be set here but TypeScript wants this check
             runtime.lastRequest &&
-            this._maxIdleTime &&
-            timeSince(runtime.lastRequest) > this._maxIdleTime,
+            this.#maxIdleTime &&
+            timeSince(runtime.lastRequest) > this.#maxIdleTime,
         )
         .map(([snapId]) => this.stopSnap(snapId, SnapStatusEvents.Stop)),
     );
@@ -1045,7 +1043,7 @@ export class SnapController extends BaseController<
   }
 
   async _onOutboundRequest(snapId: SnapId) {
-    const runtime = this.getRuntimeExpect(snapId);
+    const runtime = this.#getRuntimeExpect(snapId);
     // Ideally we would only pause the pending request that is making the outbound request
     // but right now we don't have a way to know which request initiated the outbound request
     runtime.pendingInboundRequests
@@ -1055,7 +1053,7 @@ export class SnapController extends BaseController<
   }
 
   async _onOutboundResponse(snapId: SnapId) {
-    const runtime = this.getRuntimeExpect(snapId);
+    const runtime = this.#getRuntimeExpect(snapId);
     runtime.pendingOutboundRequests -= 1;
     if (runtime.pendingOutboundRequests === 0) {
       runtime.pendingInboundRequests
@@ -1076,11 +1074,8 @@ export class SnapController extends BaseController<
    * @param snapId - The id of the snap to transition.
    * @param event - The event enum to use to transition.
    */
-  private transition(
-    snapId: SnapId,
-    event: StatusEvents | StatusEvents['type'],
-  ) {
-    const { interpreter } = this.getRuntimeExpect(snapId);
+  #transition(snapId: SnapId, event: StatusEvents | StatusEvents['type']) {
+    const { interpreter } = this.#getRuntimeExpect(snapId);
     interpreter.send(event);
     this.update((state: any) => {
       state.snaps[snapId].status = interpreter.state.value;
@@ -1094,7 +1089,7 @@ export class SnapController extends BaseController<
    * @param snapId - The id of the Snap to start.
    */
   async startSnap(snapId: SnapId): Promise<void> {
-    const runtime = this.getRuntimeExpect(snapId);
+    const runtime = this.#getRuntimeExpect(snapId);
 
     if (this.state.snaps[snapId].enabled === false) {
       throw new Error(`Snap "${snapId}" is disabled.`);
@@ -1102,7 +1097,7 @@ export class SnapController extends BaseController<
 
     assert(runtime.sourceCode);
 
-    await this._startSnap({
+    await this.#startSnap({
       snapId,
       sourceCode: runtime.sourceCode,
     });
@@ -1162,7 +1157,7 @@ export class SnapController extends BaseController<
       | SnapStatusEvents.Stop
       | SnapStatusEvents.Crash = SnapStatusEvents.Stop,
   ): Promise<void> {
-    const runtime = this.getRuntime(snapId);
+    const runtime = this.#getRuntime(snapId);
     if (!runtime) {
       throw new Error(`The snap "${snapId}" is not running.`);
     }
@@ -1173,12 +1168,12 @@ export class SnapController extends BaseController<
     runtime.pendingOutboundRequests = 0;
     try {
       if (this.isRunning(snapId)) {
-        this._closeAllConnections(snapId);
-        await this.terminateSnap(snapId);
+        this.#closeAllConnections(snapId);
+        await this.#terminateSnap(snapId);
       }
     } finally {
       if (this.isRunning(snapId)) {
-        this.transition(snapId, statusEvent);
+        this.#transition(snapId, statusEvent);
       }
     }
   }
@@ -1188,7 +1183,7 @@ export class SnapController extends BaseController<
    *
    * @param snapId - The snap to terminate.
    */
-  private async terminateSnap(snapId: SnapId) {
+  async #terminateSnap(snapId: SnapId) {
     await this.messagingSystem.call('ExecutionService:terminateSnap', snapId);
     this.messagingSystem.publish(
       'SnapController:snapTerminated',
@@ -1278,8 +1273,8 @@ export class SnapController extends BaseController<
    * @param newSnapState - The new state of the snap.
    */
   async updateSnapState(snapId: SnapId, newSnapState: Json): Promise<void> {
-    const encrypted = await this.encryptSnapState(snapId, newSnapState);
-    const runtime = this.getRuntimeExpect(snapId);
+    const encrypted = await this.#encryptSnapState(snapId, newSnapState);
+    const runtime = this.#getRuntimeExpect(snapId);
     runtime.state = encrypted;
   }
 
@@ -1290,7 +1285,7 @@ export class SnapController extends BaseController<
    * @param snapId - The id of the Snap whose state should be cleared.
    */
   async clearSnapState(snapId: SnapId): Promise<void> {
-    const runtime = this.getRuntimeExpect(snapId);
+    const runtime = this.#getRuntimeExpect(snapId);
     runtime.state = null;
   }
 
@@ -1339,24 +1334,21 @@ export class SnapController extends BaseController<
    * @throws If the snap state decryption fails.
    */
   async getSnapState(snapId: SnapId): Promise<Json> {
-    const { state } = this.getRuntimeExpect(snapId);
-    return state ? this.decryptSnapState(snapId, state) : null;
+    const { state } = this.#getRuntimeExpect(snapId);
+    return state ? this.#decryptSnapState(snapId, state) : null;
   }
 
-  private async getEncryptionKey(snapId: SnapId): Promise<string> {
-    return this._getAppKey(snapId, AppKeyType.stateEncryption);
+  async #getEncryptionKey(snapId: SnapId): Promise<string> {
+    return this.#getAppKey(snapId, AppKeyType.stateEncryption);
   }
 
-  private async encryptSnapState(snapId: SnapId, state: Json): Promise<string> {
-    const appKey = await this.getEncryptionKey(snapId);
+  async #encryptSnapState(snapId: SnapId, state: Json): Promise<string> {
+    const appKey = await this.#getEncryptionKey(snapId);
     return passworder.encrypt(appKey, state);
   }
 
-  private async decryptSnapState(
-    snapId: SnapId,
-    encrypted: string,
-  ): Promise<Json> {
-    const appKey = await this.getEncryptionKey(snapId);
+  async #decryptSnapState(snapId: SnapId, encrypted: string): Promise<Json> {
+    const appKey = await this.#getEncryptionKey(snapId);
     try {
       return await passworder.decrypt(appKey, encrypted);
     } catch (err) {
@@ -1373,7 +1365,7 @@ export class SnapController extends BaseController<
   clearState() {
     const snapIds = Object.keys(this.state.snaps);
     snapIds.forEach((snapId) => {
-      this._closeAllConnections(snapId);
+      this.#closeAllConnections(snapId);
     });
     this.messagingSystem.call('ExecutionService:terminateAllSnaps');
     snapIds.forEach(this.revokeAllSnapPermissions);
@@ -1422,7 +1414,7 @@ export class SnapController extends BaseController<
           permissionName,
         );
 
-        this._snapsRuntimeData.delete(snapId);
+        this.snapsRuntimeData.delete(snapId);
 
         this.update((state: any) => {
           delete state.snaps[snapId];
@@ -1459,7 +1451,7 @@ export class SnapController extends BaseController<
    * @param snapId - The snap id of the snap that was referenced.
    */
   incrementActiveReferences(snapId: SnapId) {
-    const runtime = this.getRuntimeExpect(snapId);
+    const runtime = this.#getRuntimeExpect(snapId);
     runtime.activeReferences += 1;
   }
 
@@ -1469,7 +1461,7 @@ export class SnapController extends BaseController<
    * @param snapId - The snap id of the snap that was referenced..
    */
   decrementActiveReferences(snapId: SnapId) {
-    const runtime = this.getRuntimeExpect(snapId);
+    const runtime = this.#getRuntimeExpect(snapId);
     assert(
       runtime.activeReferences > 0,
       'SnapController reference management is in an invalid state.',
@@ -1600,7 +1592,7 @@ export class SnapController extends BaseController<
         return existingSnap;
       }
 
-      if (this._featureFlags.dappsCanUpdateSnaps === true) {
+      if (this.#featureFlags.dappsCanUpdateSnaps === true) {
         try {
           const updateResult = await this.updateSnap(
             origin,
@@ -1633,7 +1625,7 @@ export class SnapController extends BaseController<
     }
 
     try {
-      const { sourceCode } = await this._add({
+      const { sourceCode } = await this.#add({
         origin,
         id: snapId,
         versionRange,
@@ -1641,7 +1633,7 @@ export class SnapController extends BaseController<
 
       await this.authorize(origin, snapId);
 
-      await this._startSnap({
+      await this.#startSnap({
         snapId,
         sourceCode,
       });
@@ -1690,7 +1682,7 @@ export class SnapController extends BaseController<
       );
     }
 
-    const newSnap = await this._fetchSnap(snapId, newVersionRange);
+    const newSnap = await this.fetchSnap(snapId, newVersionRange);
     const newVersion = newSnap.manifest.version;
     if (!gtVersion(newVersion, snap.version)) {
       console.warn(
@@ -1699,17 +1691,17 @@ export class SnapController extends BaseController<
       return null;
     }
 
-    await this._assertIsUnblocked(snapId, {
+    await this.#assertIsUnblocked(snapId, {
       version: newVersion,
       shasum: newSnap.manifest.source.shasum,
     });
 
-    const processedPermissions = this.processSnapPermissions(
+    const processedPermissions = this.#processSnapPermissions(
       newSnap.manifest.initialPermissions,
     );
 
     const { newPermissions, unusedPermissions, approvedPermissions } =
-      await this.calculatePermissionsChange(snapId, processedPermissions);
+      await this.#calculatePermissionsChange(snapId, processedPermissions);
 
     const id = nanoid();
     const { permissions: approvedNewPermissions, ...requestData } =
@@ -1737,9 +1729,9 @@ export class SnapController extends BaseController<
       await this.stopSnap(snapId, SnapStatusEvents.Stop);
     }
 
-    this.transition(snapId, SnapStatusEvents.Update);
+    this.#transition(snapId, SnapStatusEvents.Update);
 
-    this._set({
+    this.#set({
       origin,
       id: snapId,
       manifest: newSnap.manifest,
@@ -1765,7 +1757,7 @@ export class SnapController extends BaseController<
       });
     }
 
-    await this._startSnap({ snapId, sourceCode: newSnap.sourceCode });
+    await this.#startSnap({ snapId, sourceCode: newSnap.sourceCode });
 
     const truncatedSnap = this.getTruncatedExpect(snapId);
 
@@ -1786,7 +1778,7 @@ export class SnapController extends BaseController<
    * version.
    * @returns The resulting snap object.
    */
-  private async _add(args: AddSnapArgs): Promise<PersistedSnap> {
+  async #add(args: AddSnapArgs): Promise<PersistedSnap> {
     const { id: snapId } = args;
     validateSnapId(snapId);
 
@@ -1799,8 +1791,8 @@ export class SnapController extends BaseController<
     ) {
       throw new Error(`Invalid add snap args for snap "${snapId}".`);
     }
-    this.setupRuntime(snapId, { sourceCode: null, state: null });
-    const runtime = this.getRuntimeExpect(snapId);
+    this.#setupRuntime(snapId, { sourceCode: null, state: null });
+    const runtime = this.#getRuntimeExpect(snapId);
     if (!runtime.installPromise) {
       console.info(`Adding snap: ${snapId}`);
 
@@ -1808,16 +1800,16 @@ export class SnapController extends BaseController<
       // to null in the authorize() method.
       runtime.installPromise = (async () => {
         if ('manifest' in args && 'sourceCode' in args) {
-          return this._set({ ...args, id: snapId });
+          return this.#set({ ...args, id: snapId });
         }
 
-        const fetchedSnap = await this._fetchSnap(snapId, args.versionRange);
-        await this._assertIsUnblocked(snapId, {
+        const fetchedSnap = await this.fetchSnap(snapId, args.versionRange);
+        await this.#assertIsUnblocked(snapId, {
           version: fetchedSnap.manifest.version,
           shasum: fetchedSnap.manifest.source.shasum,
         });
 
-        return this._set({
+        return this.#set({
           ...args,
           ...fetchedSnap,
           id: snapId,
@@ -1835,24 +1827,24 @@ export class SnapController extends BaseController<
     }
   }
 
-  private async _startSnap(snapData: { snapId: string; sourceCode: string }) {
+  async #startSnap(snapData: { snapId: string; sourceCode: string }) {
     const { snapId } = snapData;
     if (this.isRunning(snapId)) {
       throw new Error(`Snap "${snapId}" is already started.`);
     }
 
     try {
-      const result = await this._executeWithTimeout(
+      const result = await this.#executeWithTimeout(
         snapId,
         this.messagingSystem.call('ExecutionService:executeSnap', {
           ...snapData,
-          endowments: await this._getEndowments(snapId),
+          endowments: await this.#getEndowments(snapId),
         }),
       );
-      this.transition(snapId, SnapStatusEvents.Start);
+      this.#transition(snapId, SnapStatusEvents.Start);
       return result;
     } catch (err) {
-      await this.terminateSnap(snapId);
+      await this.#terminateSnap(snapId);
       throw err;
     }
   }
@@ -1868,10 +1860,10 @@ export class SnapController extends BaseController<
    * @param snapId - The id of the snap whose SES endowments to get.
    * @returns An array of the names of the endowments.
    */
-  private async _getEndowments(snapId: string): Promise<string[]> {
+  async #getEndowments(snapId: string): Promise<string[]> {
     let allEndowments: string[] = [];
 
-    for (const permissionName of this._environmentEndowmentPermissions) {
+    for (const permissionName of this.#environmentEndowmentPermissions) {
       if (
         await this.messagingSystem.call(
           'PermissionController:hasPermission',
@@ -1930,7 +1922,7 @@ export class SnapController extends BaseController<
    * @param args - The add snap args.
    * @returns The resulting snap object.
    */
-  private _set(args: SetSnapArgs): PersistedSnap {
+  #set(args: SetSnapArgs): PersistedSnap {
     const {
       id: snapId,
       origin,
@@ -1991,7 +1983,7 @@ export class SnapController extends BaseController<
       id: snapId,
       initialPermissions,
       manifest,
-      status: this._statusMachine.config.initial as StatusStates['value'],
+      status: this.#statusMachine.config.initial as StatusStates['value'],
       version,
       versionHistory,
     };
@@ -2003,7 +1995,7 @@ export class SnapController extends BaseController<
       state.snaps[snapId] = snap;
     });
 
-    const runtime = this.getRuntimeExpect(snapId);
+    const runtime = this.#getRuntimeExpect(snapId);
     runtime.sourceCode = sourceCode;
 
     this.messagingSystem.publish(`SnapController:snapAdded`, snap, svgIcon);
@@ -2013,11 +2005,13 @@ export class SnapController extends BaseController<
   /**
    * Fetches the manifest and source code of a snap.
    *
+   * This function is not hash private yet because of tests.
+   *
    * @param snapId - The id of the Snap.
    * @param versionRange - The SemVer version of the Snap to fetch.
    * @returns A tuple of the Snap manifest object and the Snap source code.
    */
-  private async _fetchSnap(
+  async fetchSnap(
     snapId: ValidatedSnapId,
     versionRange: string = DEFAULT_REQUESTED_SNAP_VERSION,
   ): Promise<FetchSnapResult> {
@@ -2025,9 +2019,9 @@ export class SnapController extends BaseController<
       const snapPrefix = getSnapPrefix(snapId);
       switch (snapPrefix) {
         case SnapIdPrefixes.local:
-          return this._fetchLocalSnap(snapId.replace(SnapIdPrefixes.local, ''));
+          return this.#fetchLocalSnap(snapId.replace(SnapIdPrefixes.local, ''));
         case SnapIdPrefixes.npm:
-          return this._fetchNpmSnap(
+          return this.#fetchNpmSnap(
             snapId.replace(SnapIdPrefixes.npm, ''),
             versionRange,
           );
@@ -2043,7 +2037,7 @@ export class SnapController extends BaseController<
     }
   }
 
-  private async _fetchNpmSnap(
+  async #fetchNpmSnap(
     packageName: string,
     versionRange: string,
   ): Promise<FetchSnapResult> {
@@ -2056,8 +2050,8 @@ export class SnapController extends BaseController<
     const { manifest, sourceCode, svgIcon } = await fetchNpmSnap(
       packageName,
       versionRange,
-      this._npmRegistryUrl,
-      this._fetchFunction,
+      this.#npmRegistryUrl,
+      this.#fetchFunction,
     );
     return { manifest, sourceCode, svgIcon };
   }
@@ -2068,9 +2062,7 @@ export class SnapController extends BaseController<
    * @param localhostUrl - The localhost URL to download from.
    * @returns The validated manifest and the source code.
    */
-  private async _fetchLocalSnap(
-    localhostUrl: string,
-  ): Promise<FetchSnapResult> {
+  async #fetchLocalSnap(localhostUrl: string): Promise<FetchSnapResult> {
     // Local snaps are mostly used for development purposes. Fetches were cached in the browser and were not requested
     // afterwards which lead to confusing development where old versions of snaps were installed.
     // Thus we disable caching
@@ -2083,7 +2075,7 @@ export class SnapController extends BaseController<
     }
 
     const manifest = await (
-      await this._fetchFunction(manifestUrl.toString(), fetchOptions)
+      await this.#fetchFunction(manifestUrl.toString(), fetchOptions)
     ).json();
     assertIsSnapManifest(manifest);
 
@@ -2097,14 +2089,14 @@ export class SnapController extends BaseController<
 
     const [sourceCode, svgIcon] = await Promise.all([
       (
-        await this._fetchFunction(
+        await this.#fetchFunction(
           new URL(filePath, localhostUrl).toString(),
           fetchOptions,
         )
       ).text(),
       iconPath
         ? (
-            await this._fetchFunction(
+            await this.#fetchFunction(
               new URL(iconPath, localhostUrl).toString(),
               fetchOptions,
             )
@@ -2128,7 +2120,7 @@ export class SnapController extends BaseController<
    * @returns The processed permissions.
    * @private
    */
-  private processSnapPermissions(
+  #processSnapPermissions(
     initialPermissions: SnapPermissions,
   ): Record<
     string,
@@ -2155,6 +2147,8 @@ export class SnapController extends BaseController<
    * Initiates a request for the given snap's initial permissions.
    * Must be called in order. See processRequestedSnap.
    *
+   * This function is not hash private yet because of tests.
+   *
    * @param origin - The origin of the install request.
    * @param snapId - The id of the Snap.
    * @returns The snap's approvedPermissions.
@@ -2167,7 +2161,7 @@ export class SnapController extends BaseController<
 
     try {
       const processedPermissions =
-        this.processSnapPermissions(initialPermissions);
+        this.#processSnapPermissions(initialPermissions);
       const id = nanoid();
       const { permissions: approvedPermissions, ...requestData } =
         (await this.messagingSystem.call(
@@ -2197,7 +2191,7 @@ export class SnapController extends BaseController<
         );
       }
     } finally {
-      const runtime = this.getRuntimeExpect(snapId);
+      const runtime = this.#getRuntimeExpect(snapId);
       runtime.installPromise = null;
     }
   }
@@ -2205,8 +2199,8 @@ export class SnapController extends BaseController<
   destroy() {
     super.destroy();
 
-    if (this._timeoutForLastRequestStatus) {
-      clearTimeout(this._timeoutForLastRequestStatus);
+    if (this.#timeoutForLastRequestStatus) {
+      clearTimeout(this.#timeoutForLastRequestStatus);
     }
 
     this.messagingSystem.unsubscribe(
@@ -2241,7 +2235,7 @@ export class SnapController extends BaseController<
     handler: handlerType,
     request,
   }: SnapRpcHookArgs & { snapId: SnapId }): Promise<unknown> {
-    const handler = await this.getRpcRequestHandler(snapId);
+    const handler = await this.#getRpcRequestHandler(snapId);
     if (!handler) {
       throw new Error(
         `Snap RPC message handler not found for snap "${snapId}".`,
@@ -2256,8 +2250,8 @@ export class SnapController extends BaseController<
    * @param snapId - The id of the Snap whose message handler to get.
    * @returns The RPC handler for the given snap.
    */
-  private async getRpcRequestHandler(snapId: SnapId): Promise<SnapRpcHook> {
-    const runtime = this.getRuntimeExpect(snapId);
+  async #getRpcRequestHandler(snapId: SnapId): Promise<SnapRpcHook> {
+    const runtime = this.#getRuntimeExpect(snapId);
     const existingHandler = runtime.rpcHandler;
     if (existingHandler) {
       return existingHandler;
@@ -2316,8 +2310,8 @@ export class SnapController extends BaseController<
         });
       }
 
-      const timer = new Timer(this._maxRequestTime);
-      this._recordSnapRpcRequestStart(snapId, request.id, timer);
+      const timer = new Timer(this.maxRequestTime);
+      this.#recordSnapRpcRequestStart(snapId, request.id, timer);
 
       const handleRpcRequestPromise = this.messagingSystem.call(
         'ExecutionService:handleRpcRequest',
@@ -2327,12 +2321,12 @@ export class SnapController extends BaseController<
 
       // This will either get the result or reject due to the timeout.
       try {
-        const result = await this._executeWithTimeout(
+        const result = await this.#executeWithTimeout(
           snapId,
           handleRpcRequestPromise,
           timer,
         );
-        this._recordSnapRpcRequestFinish(snapId, request.id);
+        this.#recordSnapRpcRequestFinish(snapId, request.id);
         return result;
       } catch (err) {
         await this.stopSnap(snapId, SnapStatusEvents.Crash);
@@ -2354,7 +2348,7 @@ export class SnapController extends BaseController<
    * @returns The result of the promise or rejects if the promise times out.
    * @template PromiseValue - The value of the Promise.
    */
-  private async _executeWithTimeout<PromiseValue>(
+  async #executeWithTimeout<PromiseValue>(
     snapId: SnapId,
     promise: Promise<PromiseValue>,
     timer?: Timer,
@@ -2370,25 +2364,21 @@ export class SnapController extends BaseController<
       return promise;
     }
 
-    const result = await withTimeout(promise, timer ?? this._maxRequestTime);
+    const result = await withTimeout(promise, timer ?? this.maxRequestTime);
     if (result === hasTimedOut) {
       throw new Error('The request timed out.');
     }
     return result;
   }
 
-  private _recordSnapRpcRequestStart(
-    snapId: SnapId,
-    requestId: unknown,
-    timer: Timer,
-  ) {
-    const runtime = this.getRuntimeExpect(snapId);
+  #recordSnapRpcRequestStart(snapId: SnapId, requestId: unknown, timer: Timer) {
+    const runtime = this.#getRuntimeExpect(snapId);
     runtime.pendingInboundRequests.push({ requestId, timer });
     runtime.lastRequest = null;
   }
 
-  private _recordSnapRpcRequestFinish(snapId: SnapId, requestId: unknown) {
-    const runtime = this.getRuntimeExpect(snapId);
+  #recordSnapRpcRequestFinish(snapId: SnapId, requestId: unknown) {
+    const runtime = this.#getRuntimeExpect(snapId);
     runtime.pendingInboundRequests = runtime.pendingInboundRequests.filter(
       (r) => r.requestId !== requestId,
     );
@@ -2398,12 +2388,12 @@ export class SnapController extends BaseController<
     }
   }
 
-  private getRuntime(snapId: SnapId): SnapRuntimeData | undefined {
-    return this._snapsRuntimeData.get(snapId);
+  #getRuntime(snapId: SnapId): SnapRuntimeData | undefined {
+    return this.snapsRuntimeData.get(snapId);
   }
 
-  private getRuntimeExpect(snapId: SnapId): SnapRuntimeData {
-    const runtime = this.getRuntime(snapId);
+  #getRuntimeExpect(snapId: SnapId): SnapRuntimeData {
+    const runtime = this.#getRuntime(snapId);
     assert(
       runtime !== undefined,
       new Error(`Snap "${snapId}" runtime data not found`),
@@ -2411,26 +2401,26 @@ export class SnapController extends BaseController<
     return runtime;
   }
 
-  private setupRuntime(
+  #setupRuntime(
     snapId: SnapId,
     data: { sourceCode: string | null; state: string | null },
   ) {
-    if (this._snapsRuntimeData.has(snapId)) {
+    if (this.snapsRuntimeData.has(snapId)) {
       return;
     }
 
     const snap = this.get(snapId);
-    const interpreter = interpret(this._statusMachine);
+    const interpreter = interpret(this.#statusMachine);
     interpreter.start({
       context: { snapId },
       value:
         snap?.status ??
-        (this._statusMachine.config.initial as StatusStates['value']),
+        (this.#statusMachine.config.initial as StatusStates['value']),
     });
 
     forceStrict(interpreter);
 
-    this._snapsRuntimeData.set(snapId, {
+    this.snapsRuntimeData.set(snapId, {
       lastRequest: null,
       rpcHandler: null,
       installPromise: null,
@@ -2442,7 +2432,7 @@ export class SnapController extends BaseController<
     });
   }
 
-  private async calculatePermissionsChange(
+  async #calculatePermissionsChange(
     snapId: SnapId,
     desiredPermissionsSet: RequestedSnapPermissions,
   ): Promise<{