diff --git a/.eslintignore b/.eslintignore
index 8eddcaf960..76734040fb 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -64,7 +64,7 @@ packages/tools/PortableAppsLauncher
 packages/fork-*
 plugin_types/
 readme/
-commands/index.ts
+**/commands/index.ts
 
 # AUTO-GENERATED - EXCLUDED TYPESCRIPT BUILD
 packages/app-cli/app/LinkSelector.d.ts
@@ -886,6 +886,9 @@ packages/lib/JoplinServerApi.js.map
 packages/lib/Logger.d.ts
 packages/lib/Logger.js
 packages/lib/Logger.js.map
+packages/lib/ObjectUtils.d.ts
+packages/lib/ObjectUtils.js
+packages/lib/ObjectUtils.js.map
 packages/lib/PoorManIntervals.d.ts
 packages/lib/PoorManIntervals.js
 packages/lib/PoorManIntervals.js.map
diff --git a/.gitignore b/.gitignore
index 5b853f4aec..9cb006831f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -871,6 +871,9 @@ packages/lib/JoplinServerApi.js.map
 packages/lib/Logger.d.ts
 packages/lib/Logger.js
 packages/lib/Logger.js.map
+packages/lib/ObjectUtils.d.ts
+packages/lib/ObjectUtils.js
+packages/lib/ObjectUtils.js.map
 packages/lib/PoorManIntervals.d.ts
 packages/lib/PoorManIntervals.js
 packages/lib/PoorManIntervals.js.map
diff --git a/packages/lib/ObjectUtils.js b/packages/lib/ObjectUtils.ts
similarity index 66%
rename from packages/lib/ObjectUtils.js
rename to packages/lib/ObjectUtils.ts
index e0b2664533..02fc566cf8 100644
--- a/packages/lib/ObjectUtils.js
+++ b/packages/lib/ObjectUtils.ts
@@ -1,6 +1,4 @@
-const ObjectUtils = {};
-
-ObjectUtils.sortByValue = function(object) {
+export function sortByValue(object: any) {
 	const temp = [];
 	for (const k in object) {
 		if (!object.hasOwnProperty(k)) continue;
@@ -19,16 +17,16 @@ ObjectUtils.sortByValue = function(object) {
 		return v1 < v2 ? -1 : +1;
 	});
 
-	const output = {};
+	const output: any = {};
 	for (let i = 0; i < temp.length; i++) {
 		const item = temp[i];
 		output[item.key] = item.value;
 	}
 
 	return output;
-};
+}
 
-ObjectUtils.fieldsEqual = function(o1, o2) {
+export function fieldsEqual(o1: any, o2: any) {
 	if ((!o1 || !o2) && o1 !== o2) return false;
 
 	for (const k in o1) {
@@ -42,10 +40,10 @@ ObjectUtils.fieldsEqual = function(o1, o2) {
 	if (c1.length !== c2.length) return false;
 
 	return true;
-};
+}
 
-ObjectUtils.convertValuesToFunctions = function(o) {
-	const output = {};
+export function convertValuesToFunctions(o: any) {
+	const output: any = {};
 	for (const n in o) {
 		if (!o.hasOwnProperty(n)) continue;
 		output[n] = () => {
@@ -53,11 +51,26 @@ ObjectUtils.convertValuesToFunctions = function(o) {
 		};
 	}
 	return output;
-};
+}
 
-ObjectUtils.isEmpty = function(o) {
+export function isEmpty(o: any) {
 	if (!o) return true;
 	return Object.keys(o).length === 0 && o.constructor === Object;
-};
+}
 
-module.exports = ObjectUtils;
+// export function isStringifiable(o:any):boolean {
+// 	if (o === null || o === undefined) return true;
+
+// 	if (Array.isArray(o)) {
+// 		for (const e of o) {
+// 			if (!isStringifiable(e)) return false;
+// 		}
+// 		return true;
+// 	}
+
+// 	if (typeof o === 'object') {
+
+// 	}
+
+// 	return true;
+// }
diff --git a/packages/lib/services/interop/InteropService_Importer_Base.ts b/packages/lib/services/interop/InteropService_Importer_Base.ts
index 199ca63605..f44ac26356 100644
--- a/packages/lib/services/interop/InteropService_Importer_Base.ts
+++ b/packages/lib/services/interop/InteropService_Importer_Base.ts
@@ -5,27 +5,28 @@ import { ImportExportResult } from './types';
 import Setting from '../../models/Setting';
 
 export default class InteropService_Importer_Base {
+
 	private metadata_: any = null;
 	protected sourcePath_: string = '';
 	protected options_: any = {};
 
-	setMetadata(md: any) {
+	public setMetadata(md: any) {
 		this.metadata_ = md;
 	}
 
-	metadata() {
+	public metadata() {
 		return this.metadata_;
 	}
 
-	async init(sourcePath: string, options: any) {
+	public async init(sourcePath: string, options: any) {
 		this.sourcePath_ = sourcePath;
 		this.options_ = options;
 	}
 
 	// @ts-ignore
-	async exec(result: ImportExportResult): Promise<ImportExportResult> {}
+	public async exec(result: ImportExportResult): Promise<ImportExportResult> {}
 
-	async temporaryDirectory_(createIt: boolean) {
+	protected async temporaryDirectory_(createIt: boolean) {
 		const md5 = require('md5');
 		const tempDir = `${Setting.value('tempDir')}/${md5(Math.random() + Date.now())}`;
 		if (createIt) await require('fs-extra').mkdirp(tempDir);
diff --git a/packages/lib/services/interop/InteropService_Importer_Custom.ts b/packages/lib/services/interop/InteropService_Importer_Custom.ts
index e289b2e8ef..4d0c5641c1 100644
--- a/packages/lib/services/interop/InteropService_Importer_Custom.ts
+++ b/packages/lib/services/interop/InteropService_Importer_Custom.ts
@@ -5,15 +5,27 @@ export default class InteropService_Importer_Custom extends InteropService_Impor
 
 	private module_: Module = null;
 
-	constructor(handler: Module) {
+	public constructor(handler: Module) {
 		super();
 		this.module_ = handler;
 	}
 
-	async exec(result: ImportExportResult): Promise<ImportExportResult> {
+	public async exec(result: ImportExportResult): Promise<ImportExportResult> {
+		// When passing the options to the plugin, we strip off any function
+		// because they won't serialized over ipc.
+
+		const processedOptions: any = {};
+
+		if (this.options_) {
+			for (const [k, v] of Object.entries(this.options_)) {
+				if (typeof v === 'function') continue;
+				processedOptions[k] = v;
+			}
+		}
+
 		return this.module_.onExec({
 			sourcePath: this.sourcePath_,
-			options: this.options_,
+			options: processedOptions,
 			warnings: result.warnings,
 		});
 	}