3 files changed, 29 insertions, 23 deletions

diff --git a/src/scripts/common/login/captcha.ts b/src/scripts/common/login/captcha.ts
index 73e8995..a63aa24 100644
--- a/src/scripts/common/login/captcha.ts
+++ b/src/scripts/common/login/captcha.ts
@@ -1,4 +1,5 @@
 import { observeDOM } from "@/shared/observe-dom";
+import { OCRRequest, OCRResponse } from "@/shared/ocr-request";
 
 /**
  * Pre-processes a CAPTCHA image on a canvas by removing grayish
@@ -9,18 +10,18 @@ import { observeDOM } from "@/shared/observe-dom";
  * @param width  - Canvas width in pixels.
  * @param height - Canvas height in pixels.
  */
-export function prepareCaptcha(ctx: CanvasRenderingContext2D, width: number, height: number) {
+export function prepareCaptcha(ctx: CanvasRenderingContext2D, width: number, height: number): void {
 	const imgData = ctx.getImageData(0, 0, width, height);
 	const data = imgData.data;
 	const radius = 1;
 
 	/** Returns true when all three channels are below 50 (very dark). */
-	function isBlack(r: number, g: number, b: number) {
+	function isBlack(r: number, g: number, b: number): boolean {
 		return r < 50 && g < 50 && b < 50;
 	}
 
 	/** Returns true when the colour is a mid-range grey (no strong hue). */
-	function isGrayish(r: number, g: number, b: number) {
+	function isGrayish(r: number, g: number, b: number): boolean {
 		return Math.abs(r - g) < 15 && Math.abs(g - b) < 15 && r > 100 && r < 200;
 	}
 
@@ -28,7 +29,7 @@ export function prepareCaptcha(ctx: CanvasRenderingContext2D, width: number, hei
 	 * Checks whether a black pixel exists within `radius` pixels of (x, y).
 	 * Used to preserve dark structures when removing grey noise.
 	 */
-	function hasNearbyBlack(x: number, y: number) {
+	function hasNearbyBlack(x: number, y: number): boolean {
 		for (let dx = -radius; dx <= radius; dx++) {
 			for (let dy = -radius; dy <= radius; dy++) {
 				const nx = x + dx;
@@ -65,14 +66,17 @@ export function prepareCaptcha(ctx: CanvasRenderingContext2D, width: number, hei
 }
 
 observeDOM(() => {
-	const loginFormElement = document.querySelector("#loginform") as (HTMLFormElement | undefined);
+	const loginFormElement = document.querySelector<HTMLFormElement>("#loginform");
 
 	if (loginFormElement) {
-		const captchaImg = loginFormElement.querySelector("#captchaImg") as HTMLImageElement;
-		const captchaInput = loginFormElement.querySelector("#txtInput") as HTMLInputElement;
+		const captchaImg = loginFormElement.querySelector<HTMLImageElement>("#captchaImg");
+		const captchaInput = loginFormElement.querySelector<HTMLInputElement>("#txtInput");
+
+		if (!captchaImg || !captchaInput)
+			return false;
 
 		// Wait for image to load to get correct dimensions
-		captchaImg.addEventListener("load", async () => {
+		captchaImg.addEventListener("load", function(): void {
 			const { width, height } = captchaImg;
 
 			// 1. Create canvas
@@ -86,33 +90,35 @@ observeDOM(() => {
 			canvas.style.display = "none";
 
 			// 3. Insert canvas before image
-			captchaImg.parentNode!.querySelectorAll("canvas").forEach(c => c.remove());
-			captchaImg.parentNode!.insertBefore(canvas, captchaImg);
+			captchaImg.parentNode?.querySelectorAll("canvas")
+				.forEach((c) => { c.remove(); });
+			captchaImg.parentNode?.insertBefore(canvas, captchaImg);
 
 			// 4. Hide image
 			captchaImg.style.display = "none";
 
 			// 5. Draw the image onto the canvas
-			const ctx = canvas.getContext("2d")!;
+			const ctx = canvas.getContext("2d");
+			if (!ctx)
+				return;
 			ctx.drawImage(captchaImg, 0, 0);
 			prepareCaptcha(ctx, canvas.width, canvas.height);
 			canvas.style.display = "";
 			const dataURL = canvas.toDataURL("image/png");
 
 			// Perform OCR
-			chrome.runtime.sendMessage(
+			chrome.runtime.sendMessage<OCRRequest, OCRResponse>(
 				{ type: "OCR", dataURL },
-				({ success, text, confidence }) => {
-					if (success) {
-						const textResult = text.trim();
-						if (confidence < 80 || textResult.length !== 6) {
+				function(ocrResponse): void {
+					if (ocrResponse.success) {
+						const textResult = ocrResponse.text.trim();
+						if (ocrResponse.confidence < 80 || textResult.length !== 6)
 							// Reset the captcha if confidence is low
-							captchaImg.src = "generateCaptcha?" + new Date().getTime();
-						} else {
+							captchaImg.src = `generateCaptcha?${new Date().getTime().toString()}`;
+						else
 							captchaInput.value = textResult;
-						}
 					}
-				},
+				}
 			);
 		});
 	}
diff --git a/src/scripts/common/login/index.ts b/src/scripts/common/login/index.ts
index 17e2117..95b9c5b 100644
--- a/src/scripts/common/login/index.ts
+++ b/src/scripts/common/login/index.ts
@@ -1 +1 @@
-import "@/scripts/login/captcha";
+import "@/scripts/common/login/captcha";
diff --git a/src/scripts/common/stop-blocking.ts b/src/scripts/common/stop-blocking.ts
index 3fa3de6..bdebfe9 100644
--- a/src/scripts/common/stop-blocking.ts
+++ b/src/scripts/common/stop-blocking.ts
@@ -13,7 +13,7 @@ document.addEventListener("DOMContentLoaded", () => {
 		}
 
 		return proxiedBind.apply(this, Array.from(arguments) as any);
-	}
+	};
 
 	const proxiedKeydown = $.prototype.keydown;
 	/** Proxies jQuery `.keydown()` so all key presses are allowed. */
@@ -21,7 +21,7 @@ document.addEventListener("DOMContentLoaded", () => {
 		arguments[0] = (_: any) => true;
 
 		return proxiedKeydown.apply(this, Array.from(arguments) as any);
-	}
+	};
 
 	$.prototype.bind = proxiedBind;
 	$.prototype.keydown = proxiedKeydown;