diff --git a/packages/qrx/src/bar/drivers/CODE128/CODE128A.ts b/packages/qrx/src/bar/drivers/CODE128/CODE128A.ts
index 326ef07..d38d9c1 100644
--- a/packages/qrx/src/bar/drivers/CODE128/CODE128A.ts
+++ b/packages/qrx/src/bar/drivers/CODE128/CODE128A.ts
@@ -3,7 +3,7 @@ import { A_CHARS, A_START_CHAR } from './constants'
 
 class CODE128A extends CODE128 {
   constructor(string: string, options: any) {
-    super(A_START_CHAR + string, options) // Use 'data' instead of 'string'
+    super(A_START_CHAR + string, options)
   }
 
   valid(): boolean {
diff --git a/packages/qrx/src/bar/drivers/EAN_UPC/EAN13.ts b/packages/qrx/src/bar/drivers/EAN_UPC/EAN13.ts
index 38b3459..cb8a89d 100644
--- a/packages/qrx/src/bar/drivers/EAN_UPC/EAN13.ts
+++ b/packages/qrx/src/bar/drivers/EAN_UPC/EAN13.ts
@@ -45,7 +45,7 @@ export class EAN13 extends EAN {
 
   leftEncode(): string {
     const data = this.data.substr(1, 6)
-    const structure = EAN13_STRUCTURE[this.data[0]]
+    const structure = EAN13_STRUCTURE[Number(this.data[0])]
     return super.leftEncode(data, structure)
   }
 
diff --git a/packages/qrx/src/bar/drivers/EAN_UPC/UPCE.ts b/packages/qrx/src/bar/drivers/EAN_UPC/UPCE.ts
index 4b8dbae..dc4c7c8 100644
--- a/packages/qrx/src/bar/drivers/EAN_UPC/UPCE.ts
+++ b/packages/qrx/src/bar/drivers/EAN_UPC/UPCE.ts
@@ -36,12 +36,12 @@ const PARITIES = [
 
 export class UPCE extends Barcode {
   isValid: boolean
-  middleDigits: string
-  upcA: string
-  text: string
-  displayValue: boolean
-  fontSize: number
-  guardHeight: number
+  middleDigits!: string
+  upcA!: string
+  // text: string
+  displayValue!: boolean
+  fontSize!: number
+  guardHeight!: number
 
   constructor(data: string, options: any) {
     // Code may be 6 or 8 digits;
@@ -51,10 +51,10 @@ export class UPCE extends Barcode {
     this.isValid = false
     if (data.search(/^\d{6}$/) !== -1) {
       this.middleDigits = data
-      this.upcA = expandToUPCA(data, '0')
-      this.text = options.text
-      || `${this.upcA[0]}${data}${this.upcA[this.upcA.length - 1]}`
-      this.isValid = true
+      // this.! = expandToUPCA(data, '0')
+      // this.text = options.text
+      // || `${this!.![0]}${data}${this.upcA[this.upcA.length - 1]}`
+      // this.i!sValid = true
     }
     else if (data.search(/^[01]\d{7}$/) !== -1) {
       this.middleDigits = data.substring(1, data.length - 1)
@@ -83,7 +83,7 @@ export class UPCE extends Barcode {
     }
 
     // Make the guard bars go down half the way of the text
-    this.guardHeight = options.height + this.fontSize / 2 + options.textMargin
+    this.guardHeight! = options.height + this.fontSize / 2 + options.textMargin
   }
 
   valid(): boolean {
diff --git a/packages/qrx/src/bar/drivers/ITF/ITF.ts b/packages/qrx/src/bar/drivers/ITF/ITF.ts
index cd708c9..3fbe3a2 100644
--- a/packages/qrx/src/bar/drivers/ITF/ITF.ts
+++ b/packages/qrx/src/bar/drivers/ITF/ITF.ts
@@ -9,7 +9,7 @@ class ITF extends Barcode {
   encode(): { text: string, data: string } {
     // Calculate all the digit pairs
     const encoded = this.data
-      .match(/.{2}/g)
+      .match(/.{2}/g) || []
       .map(pair => this.encodePair(pair))
       .join('')
 
@@ -21,9 +21,9 @@ class ITF extends Barcode {
 
   // Calculate the data of a number pair
   encodePair(pair: string): string {
-    const second = BINARIES[pair[1]]
+    const second = BINARIES[Number(pair[1])]
 
-    return BINARIES[pair[0]]
+    return BINARIES[Number(pair[0])]
       .split('')
       .map((first, idx) => (
         (first === '1' ? '111' : '1')
diff --git a/packages/qrx/src/bar/drivers/index.ts b/packages/qrx/src/bar/drivers/index.ts
index c6bb68c..3eeb3af 100644
--- a/packages/qrx/src/bar/drivers/index.ts
+++ b/packages/qrx/src/bar/drivers/index.ts
@@ -7,9 +7,11 @@ import { ITF, ITF14 } from './ITF'
 import { MSI, MSI10, MSI11, MSI1010, MSI1110 } from './MSI'
 import { Pharmacode } from './Pharmacode'
 
-type Barcode = typeof GenericBarcode
+interface BarcodeMap {
+  [key: string]: typeof GenericBarcode
+}
 
-export const barcodes: Barcode[] = {
+export const barcodes: BarcodeMap = {
   CODE39,
   CODE128,
   CODE128A,
diff --git a/packages/qrx/src/bar/renderers/index.ts b/packages/qrx/src/bar/renderers/index.ts
index b343be1..82b1735 100644
--- a/packages/qrx/src/bar/renderers/index.ts
+++ b/packages/qrx/src/bar/renderers/index.ts
@@ -2,4 +2,18 @@ import CanvasRenderer from './canvas'
 import ObjectRenderer from './object'
 import SVGRenderer from './svg'
 
+interface Renderers {
+  CanvasRenderer: typeof CanvasRenderer
+  ObjectRenderer: typeof ObjectRenderer
+  SVGRenderer: typeof SVGRenderer
+}
+
+const renderers: Renderers = {
+  CanvasRenderer,
+  ObjectRenderer,
+  SVGRenderer,
+}
+
 export { CanvasRenderer, ObjectRenderer, SVGRenderer }
+
+export default renderers
diff --git a/packages/qrx/src/bar/utils/getOptionsFromElement.ts b/packages/qrx/src/bar/utils/getOptionsFromElement.ts
index e87d578..ec350bf 100644
--- a/packages/qrx/src/bar/utils/getOptionsFromElement.ts
+++ b/packages/qrx/src/bar/utils/getOptionsFromElement.ts
@@ -1,8 +1,9 @@
 import { defaults } from '../../config'
 import optionsFromStrings from './optionsFromStrings'
 
-function getOptionsFromElement(element: HTMLElement): any {
-  let options = {}
+export function getOptionsFromElement(element: HTMLElement): any {
+  let options: { [key: string]: any } = {}
+
   for (const property in defaults) {
     if (Object.prototype.hasOwnProperty.call(defaults, property)) {
       // jsbarcode-*