refactor: added linting with esling and also resolved warnings for it

18 files changed, 219 insertions, 154 deletions

diff --git a/src/background/run-ocr.ts b/src/background/run-ocr.ts
index 54c9e5f..683f701 100644
--- a/src/background/run-ocr.ts
+++ b/src/background/run-ocr.ts
@@ -1,3 +1,5 @@
+import { OCRRequest, OCRResponse } from "@/shared/ocr-request";
+
 const OFFSCREEN_DOCUMENT_PATH = "offscreen/ocr/index.html";
 
 // Function to ensure the offscreen document is open
@@ -5,7 +7,7 @@ const OFFSCREEN_DOCUMENT_PATH = "offscreen/ocr/index.html";
  * Ensures the offscreen OCR document is open.  If it already exists
  * this is a no-op.
  */
-async function setupOffscreenDocument() {
+async function setupOffscreenDocument(): Promise<void> {
 	if (await chrome.offscreen.hasDocument()) {
 		return; // Offscreen document already open
 	}
@@ -22,25 +24,21 @@ async function setupOffscreenDocument() {
  * image data URL to an offscreen document for Tesseract.js processing
  * and sends the recognised text back to the caller.
  */
-chrome.runtime.onMessage.addListener((message, _sender, sendResponse) => {
+chrome.runtime.onMessage.addListener(function(message: OCRRequest, _sender, sendResponse): boolean {
 	if (message.type === "OCR" && message.dataURL) {
-		(async () => {
+		void (async function(): Promise<void> {
 			try {
 				// Ensure the offscreen document is open
 				await setupOffscreenDocument();
 
 				// Send the OCR request to the offscreen document
-				const offscreenResponse = await chrome.runtime.sendMessage({
+				const offscreenResponse = await chrome.runtime.sendMessage<OCRRequest, OCRResponse>({
 					type: "OFFSCREEN_OCR_REQUEST",
 					dataURL: message.dataURL
 				});
 
-				if (offscreenResponse && offscreenResponse.success) {
-					sendResponse(offscreenResponse);
-				} else {
-					sendResponse({ success: false, error: offscreenResponse?.error || "Unknown OCR error" });
-				}
-			} catch (error) {
+				sendResponse(offscreenResponse);
+			} catch(error) {
 				sendResponse({ success: false, error: (error as Error).message });
 			}
 		})();
diff --git a/src/html.d.ts b/src/html.d.ts
index b913216..086f645 100644
--- a/src/html.d.ts
+++ b/src/html.d.ts
@@ -1,3 +1,4 @@
 declare module "*.html" {
-	export default (replacements: any) => string;
+	function content(_replacements: Record<string, unknown>): string;
+	export default content;
 }
diff --git a/src/offscreen/ocr/index.js b/src/offscreen/ocr/index.js
index 9cbd19f..dfe93c9 100644
--- a/src/offscreen/ocr/index.js
+++ b/src/offscreen/ocr/index.js
@@ -18,12 +18,12 @@ async function performOcrInOffscreen(dataURL) {
 		ocrWorker = await Tesseract.createWorker("eng", 1, {
 			workerPath: WORKER_PATH,
 			corePath: CORE_PATH,
-			workerBlobURL: false,
+			workerBlobURL: false
 		});
 
 		await ocrWorker.setParameters({
 			// The only characters that appears
-			tessedit_char_whitelist: "ABCDEFGHJKLMNPQRSTUVWXYZ23456789",
+			tessedit_char_whitelist: "ABCDEFGHJKLMNPQRSTUVWXYZ23456789"
 		});
 	}
 
@@ -40,10 +40,10 @@ async function performOcrInOffscreen(dataURL) {
 chrome.runtime.onMessage.addListener((message, _sender, sendResponse) => {
 	if (message.type === "OFFSCREEN_OCR_REQUEST" && message.dataURL) {
 		performOcrInOffscreen(message.dataURL)
-			.then(({ text, confidence }) => {
+			.then(function({ text, confidence }) {
 				sendResponse({ success: true, text, confidence });
 			})
-			.catch(error => {
+			.catch(function(error) {
 				sendResponse({ success: false, error: error.message });
 			});
 		return true;
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;
diff --git a/src/scripts/pages/application-receipt/captcha.ts b/src/scripts/pages/application-receipt/captcha.ts
index c5bb657..94e6b0e 100644
--- a/src/scripts/pages/application-receipt/captcha.ts
+++ b/src/scripts/pages/application-receipt/captcha.ts
@@ -3,7 +3,11 @@
  * stubs the form validation so the user can proceed without
  * solving a CAPTCHA.
  */
+type WindowApplicationReceipt = {
+	validateForm?: () => boolean
+} & Window;
+
 document.addEventListener("DOMContentLoaded", () => {
 	$("#werter > div > form > div:nth-child(4)").hide();
-	(window as any).validateForm = () => true;
+	(window as WindowApplicationReceipt).validateForm = () => true;
 });
diff --git a/src/scripts/pages/know-your-property/captcha.ts b/src/scripts/pages/know-your-property/captcha.ts
index 3abdf08..e304342 100644
--- a/src/scripts/pages/know-your-property/captcha.ts
+++ b/src/scripts/pages/know-your-property/captcha.ts
@@ -3,7 +3,11 @@
  * stubs the captcha validation so the user can proceed without
  * solving a CAPTCHA.
  */
+type WindowKnowYourProperty = {
+	validateCaptcha?: () => boolean
+} & Window;
+
 document.addEventListener("DOMContentLoaded", () => {
 	$("#khatianPlotDiv > div:nth-child(6) > div").hide();
-	(window as any).validateCaptcha = () => true;
+	(window as WindowKnowYourProperty).validateCaptcha = () => true;
 });
diff --git a/src/scripts/pages/mutation-application/download-button.ts b/src/scripts/pages/mutation-application/download-button.ts
index 9503e00..6463079 100644
--- a/src/scripts/pages/mutation-application/download-button.ts
+++ b/src/scripts/pages/mutation-application/download-button.ts
@@ -1,4 +1,5 @@
 import { PDFDocument, StandardFonts } from "pdf-lib";
+
 import { observeDOM } from "@/shared/observe-dom";
 
 const sanghaFacilitationCentreBannerUrl = "$l{ /assets/sangha-facilitation-centre-banner.jpg }l$";
@@ -17,7 +18,7 @@ observeDOM(() => {
 		submitButtonElement.on("click", (submitButtonClickEvent) => {
 			submitButtonClickEvent.preventDefault();
 
-			(async () => {
+			void (async function(): Promise<void> {
 				const pdfDoc = await PDFDocument.load(await fetch("/BanglarBhumi/MutationDeclarationForm.action", {
 					method: "post",
 					credentials: "same-origin",
@@ -25,11 +26,13 @@ observeDOM(() => {
 						"Content-Type": "application/x-www-form-urlencoded"
 					},
 					body: "hdnAppNo="
-				}).then(res => res.arrayBuffer()));
+				}).then((res) => res.arrayBuffer()));
 				const pages = pdfDoc.getPages();
 				const lastPage = pages[pages.length - 1];
-				const { width, height: _ } = lastPage.getSize();
-				const bannerImage = await pdfDoc.embedJpg(await fetch(sanghaFacilitationCentreBannerUrl).then(res => res.arrayBuffer()));
+				const { width } = lastPage.getSize();
+				const bannerImage
+					= await pdfDoc.embedJpg(await fetch(sanghaFacilitationCentreBannerUrl)
+						.then((res) => res.arrayBuffer()));
 				const bannerImageHeight = width * (bannerImage.height / bannerImage.width);
 
 				lastPage.drawImage(bannerImage, {
@@ -39,7 +42,7 @@ observeDOM(() => {
 					height: bannerImageHeight
 				});
 
-				lastPage.drawText(pdfDoc.getCreationDate()!.toLocaleString(), {
+				lastPage.drawText(pdfDoc.getCreationDate()?.toLocaleString() ?? "", {
 					x: 10,
 					y: bannerImageHeight,
 					size: 12,
@@ -47,7 +50,7 @@ observeDOM(() => {
 				});
 
 				const link = document.createElement("a");
-				link.href = window.URL.createObjectURL(new Blob([new Uint8Array(await pdfDoc.save())], {type: "application/pdf"}));
+				link.href = window.URL.createObjectURL(new Blob([new Uint8Array(await pdfDoc.save())], { type: "application/pdf" }));
 				link.download = "Declaration.pdf";
 				link.click();
 			})();
diff --git a/src/scripts/pages/sheet-map/index.ts b/src/scripts/pages/sheet-map/index.ts
index a4e45b0..c16a2ae 100644
--- a/src/scripts/pages/sheet-map/index.ts
+++ b/src/scripts/pages/sheet-map/index.ts
@@ -1,23 +1,23 @@
-import { generateWebPage } from "@/shared/generate-web-page";
 import getDownloadMapPDFPageContent from "@/scripts/pages/sheet-map/download-map-pdf-page-content.html";
-import getMapPlotPolygonPathElement from "@/scripts/pages/sheet-map/map-plot-polygon-path-element.html";
 import getMapPlotNumberLabelTextElement from "@/scripts/pages/sheet-map/map-plot-number-label-text-element.html";
+import getMapPlotPolygonPathElement from "@/scripts/pages/sheet-map/map-plot-polygon-path-element.html";
 import getPlotInformationElement from "@/scripts/pages/sheet-map/plot-information-element.html";
+import { generateWebPage } from "@/shared/generate-web-page";
 
-interface PlotPolygon {
+type PlotPolygon = {
 	plotArea: number;
 	plotno: string;
-	polygon: string;
+	polygon: string
 };
 
-interface PlotNumberLabel {
+type PlotNumberLabel = {
 	plotno: string;
-	point: string;
-}
+	point: string
+};
 
-const headerElement = document.querySelector("#headerTable > tbody > tr")!;
-const plotNumberInput = document.querySelector<HTMLInputElement>("#txtPlotNo")!;
-const plotInformation = document.createElement("div") as HTMLDivElement;
+const headerElement = document.querySelector<HTMLTableRowElement>("#headerTable > tbody > tr");
+const plotNumberInput = document.querySelector<HTMLInputElement>("#txtPlotNo");
+const plotInformation = document.createElement("div");
 let plotPolygonPathElements = "";
 let plotNumberLabelTextElements = "";
 
@@ -30,13 +30,14 @@ document.body.appendChild(plotInformation);
  * @param text - The button label text.
  * @returns The created button element.
  */
-const createHeaderButton = (text: string) => {
+function createHeaderButton(text: string): HTMLButtonElement {
 	const buttonContainer = document.createElement("td");
 	const button = document.createElement("button");
 	button.innerHTML = text;
 	button.style.display = "none";
 	buttonContainer.appendChild(button);
-	headerElement.appendChild(buttonContainer);
+	if (headerElement)
+		headerElement.appendChild(buttonContainer);
 	return button;
 };
 
@@ -46,14 +47,16 @@ const createHeaderButton = (text: string) => {
  *
  * @param plotPolygon - The selected plot's data, or `null`/`undefined` to clear.
  */
-const setPlotInformation = (plotPolygon: PlotPolygon | null | undefined = null) => {
-	plotInformation.innerHTML = plotPolygon ? getPlotInformationElement({
-		area: (plotPolygon.plotArea/1000).toFixed(3),
-		plotNumber: plotPolygon.plotno
-	}) : getPlotInformationElement({
-		area: "0.000",
-		plotNumber: ""
-	});
+function setPlotInformation(plotPolygon: PlotPolygon | null | undefined = null): void {
+	plotInformation.innerHTML = plotPolygon
+		? getPlotInformationElement({
+			area: (plotPolygon.plotArea / 1000).toFixed(3),
+			plotNumber: plotPolygon.plotno
+		})
+		: getPlotInformationElement({
+			area: "0.000",
+			plotNumber: ""
+		});
 };
 
 /**
@@ -62,11 +65,10 @@ const setPlotInformation = (plotPolygon: PlotPolygon | null | undefined = null)
  *
  * @param labelPoints - Whether to include plot number text labels.
  */
-const downloadPDF = (labelPoints: boolean = true) => {
+function downloadPDF(labelPoints = true): void {
 	/** Extracts a detail value (district/block/mouza) from the header table by column index. */
-	const _getMapDetail = (i: number) => {
-		const detail = document.querySelector(`#headerTable > tbody > tr > td:nth-child(${i})`)!
-			.innerHTML
+	function _getMapDetail(i: number): string {
+		const detail = (document.querySelector<HTMLTableCellElement>(`#headerTable > tbody > tr > td:nth-child(${i.toString()})`)?.innerHTML ?? "")
 			.split("[")[1]
 			.trim();
 		return detail.substring(0, detail.length - 1);
@@ -85,33 +87,43 @@ const downloadPDF = (labelPoints: boolean = true) => {
 const downloadPDFButton = createHeaderButton("SAVE PDF");
 const downloadPDFNoLabelButton = createHeaderButton("SAVE PDF (NO LABEL)");
 
-downloadPDFButton.addEventListener("click", e => {
+downloadPDFButton.addEventListener("click", (e) => {
 	e.preventDefault();
 	downloadPDF();
 });
 
-downloadPDFNoLabelButton.addEventListener("click", e => {
+downloadPDFNoLabelButton.addEventListener("click", (e) => {
 	e.preventDefault();
 	downloadPDF(false);
 });
 
 setPlotInformation();
 
-(async () => {
+void (async function(): Promise<void> {
 	const searchParams = new URLSearchParams(window.location.search);
-	const response1 = await fetch(
-		"/BanglarBhumi/sheetMap_populateLayerData?lstSheetNo=" + searchParams.get("lstSheetNo"),
+	const sheetMapLayerDataResponse = await fetch(
+		`/BanglarBhumi/sheetMap_populateLayerData?lstSheetNo=${searchParams.get("lstSheetNo")?.toString() ?? ""}`,
 		{
 			method: "POST"
 		});
-	const plotPolygonList: PlotPolygon[] = (await response1.json()).features;
-	const response2 = await fetch(
-		"/BanglarBhumi/sheetMap_populateCentroidData?lstSheetNo=" + searchParams.get("lstSheetNo"),
+	type SheetMapLayerDataResponseType = {
+		features: PlotPolygon[]
+	};
+	const sheetMapLayerDataResponseJson
+		=	await sheetMapLayerDataResponse.json() as SheetMapLayerDataResponseType;
+	const plotPolygonList: PlotPolygon[] = sheetMapLayerDataResponseJson.features;
+	const sheetMapCentroidDataResponse = await fetch(
+		`/BanglarBhumi/sheetMap_populateCentroidData?lstSheetNo=${searchParams.get("lstSheetNo")?.toString() ?? ""}`,
 		{
 			method: "POST"
 		});
-	const plotNumberLabelList: PlotNumberLabel[] = (await response2.json()).features;
-	let plotPolygons: { [key: string]: PlotPolygon } = {};
+	type SheetMapCentroidDataResponseType = {
+		features: PlotNumberLabel[]
+	};
+	const sheetMapCentroidDataResponseJson
+		= await sheetMapCentroidDataResponse.json() as SheetMapCentroidDataResponseType;
+	const plotNumberLabelList: PlotNumberLabel[] = sheetMapCentroidDataResponseJson.features;
+	const plotPolygons: Record<string, PlotPolygon> = {};
 
 	for (const plotPolygon of plotPolygonList) {
 		const plotPolygonPoints = plotPolygon.polygon.split("(((")[1].split(")))")[0];
@@ -132,10 +144,10 @@ setPlotInformation();
 	downloadPDFButton.style.display = "inherit";
 	downloadPDFNoLabelButton.style.display = "inherit";
 
-	document.querySelector("#btnSearch")!.addEventListener("click", () => {
+	document.querySelector<HTMLButtonElement>("#btnSearch")?.addEventListener("click", () => {
 		let plotPolygon;
 		for (const p of plotPolygonList) {
-			if (p.plotno === plotNumberInput.value) {
+			if (p.plotno === plotNumberInput?.value) {
 				plotPolygon = p;
 				break;
 			}
@@ -145,7 +157,7 @@ setPlotInformation();
 
 	await new Promise<void>((resolve, _reject) => {
 		const plotElementIdsControl = setInterval(() => {
-			let plotElements = document.querySelector("#OpenLayers_Layer_Vector_25_vroot")?.children || [];
+			const plotElements = document.querySelector("#OpenLayers_Layer_Vector_25_vroot")?.children ?? [];
 			if (plotElements.length) {
 				clearInterval(plotElementIdsControl);
 				for (let i = 0; i < plotElements.length; i++) {
@@ -172,8 +184,8 @@ setPlotInformation();
 	 *
 	 * @param e - The mouse click event.
 	 */
-	const handlePlotClick = (e: MouseEvent) => {
-		document.querySelectorAll("path").forEach(e => {
+	function handlePlotClick(e: MouseEvent): void {
+		document.querySelectorAll("path").forEach((e) => {
 			e.setAttribute("fill", "#ffcc66");
 		});
 
diff --git a/src/scripts/pages/view-khatian/index.ts b/src/scripts/pages/view-khatian/index.ts
index 0be0c52..bb44a38 100644
--- a/src/scripts/pages/view-khatian/index.ts
+++ b/src/scripts/pages/view-khatian/index.ts
@@ -1,6 +1,6 @@
-import { generateWebPage } from "@/shared/generate-web-page";
-import { interceptPost } from "@/shared/intercept-jquery-ajax";
 import getDownloadInformationPDFPageContent from "@/scripts/pages/view-khatian/download-information-pdf-page-content.html";
+import { generateWebPage } from "@/shared/generate-web-page";
+import { addPostInterceptor, JQueryAjaxArgs } from "@/shared/intercept-jquery-ajax";
 
 const submitButtonElement = $("#khbutton");
 const separatorElement = $("#bodycover > div > form > hr:nth-child(2)");
@@ -20,9 +20,9 @@ const styles = Array.from(submitButtonElementComputedStyles)
  * @param selector - CSS selector for the select element.
  * @returns The text of the selected option.
  */
-const getValueOfSelectElement = (selector: string) => {
-	const element = document.querySelector<HTMLSelectElement>(selector)!;
-	return element.options[element.selectedIndex].text;
+function getValueOfSelectElement(selector: string): string {
+	const element = document.querySelector<HTMLSelectElement>(selector);
+	return element?.options[element.selectedIndex].text ?? "";
 };
 
 let isPlotInformation: boolean | null = null;
@@ -31,11 +31,11 @@ let isPlotInformation: boolean | null = null;
  * Opens a new window with a printable PDF view of the current khatian
  * or plot details, including district/block/mouza info.
  */
-const downloadInformationPDF = () => {
+function downloadInformationPDF(): void {
 	generateWebPage(
 		getDownloadInformationPDFPageContent({
 			isPlotInformation: !!isPlotInformation,
-			details: $(isPlotInformation ? "#plotdetails" : "#khdetails").html(),
+			details: $(isPlotInformation ? "#plotdetails" : "#khdetails").html() || "",
 			district: getValueOfSelectElement("#lstDistrictCode1"),
 			block: getValueOfSelectElement("#lstBlockCode1"),
 			mouza: getValueOfSelectElement("#lstMouzaList")
@@ -53,11 +53,11 @@ const downloadInformationPDF = () => {
  *
  * @param args - The `arguments` object from the intercepted `$.post` call.
  */
-const showDownloadButton = (args: any) => {
+function showDownloadButton(args: JQueryAjaxArgs): void {
 	if (isPlotInformation !== null) {
 		const callback = args[2];
-		args[2] = (data: any) => {
-			callback(data);
+		args[2] = (...data) => {
+			callback(...data);
 			const tableElement = $(isPlotInformation
 				? "#plotdetails > div:nth-child(1) > div:nth-child(4) > table > tbody"
 				: "#khdetails > table > tbody > tr > td:nth-child(1) > div:nth-child(5) > table > tbody"
@@ -77,19 +77,19 @@ const showDownloadButton = (args: any) => {
 					formElement[0].insertBefore(downloadPDFButton[0], separatorElement[0]);
 				}
 			} else if (downloadPDFButton) {
-				($(downloadPDFButton as any) as any).remove();
+				($(downloadPDFButton)).remove();
 				isPlotInformation = null;
 				downloadPDFButton = null;
 			}
-		}
+		};
 	}
 };
 
-interceptPost("plotDetailsAction_LandInfo.action", args => {
+addPostInterceptor("plotDetailsAction_LandInfo.action", (args: JQueryAjaxArgs) => {
 	isPlotInformation = true;
 	showDownloadButton(args);
 });
-interceptPost("khDetailsAction_LandInfo.action", args => {
+addPostInterceptor("khDetailsAction_LandInfo.action", (args: JQueryAjaxArgs) => {
 	isPlotInformation = false;
 	showDownloadButton(args);
 });
diff --git a/src/shared/generate-web-page.ts b/src/shared/generate-web-page.ts
index c3cc3a4..a93e2e2 100644
--- a/src/shared/generate-web-page.ts
+++ b/src/shared/generate-web-page.ts
@@ -5,7 +5,7 @@
  * @param content - The full HTML string to write.
  * @param title   - The document title (default: `"Banglar Bhumi"`).
  */
-export function generateWebPage(content: string, title: string = "Banglar Bhumi") {
+export function generateWebPage(content: string, title = "Banglar Bhumi"): void {
 	const tab = window.open("about:blank", "_blank");
 	if (!tab) {
 		return;
diff --git a/src/shared/intercept-jquery-ajax.ts b/src/shared/intercept-jquery-ajax.ts
index 7e1f54e..b627d0e 100644
--- a/src/shared/intercept-jquery-ajax.ts
+++ b/src/shared/intercept-jquery-ajax.ts
@@ -1,61 +1,86 @@
-type InterceptJqueryAjaxCallback = (args: any) => void;
+export type JQueryAjaxArgs = [
+	url: string,
+	data: string | Record<string, unknown>,
+	callback: (data: unknown, textStatus: string, jqXHR: JQuery.jqXHR) => void,
+	dataType?: string
+];
 
-interface InterceptJqueryEntry {
-	url: string;
-	callback: InterceptJqueryAjaxCallback;
+type JQueryAjaxInterceptor = (args: JQueryAjaxArgs) => void;
+
+type InterceptorRegistration = {
+	urlSuffix: string;
+	interceptor: JQueryAjaxInterceptor
 };
 
-const postIntercepts: InterceptJqueryEntry[] = [];
-const getIntercepts: InterceptJqueryEntry[] = [];
+const postInterceptors: InterceptorRegistration[] = [];
+const getInterceptors: InterceptorRegistration[] = [];
+
+// Define a strict signature to replace the unsafe `Function` type
+type OriginalJQueryAjaxMethod = (...args: unknown[]) => JQuery.jqXHR;
 
 /**
  * On DOMContentLoaded, proxies jQuery's `$.post` and `$.get` so that
  * registered interceptors are called before the real request.
  */
-document.addEventListener("DOMContentLoaded", () => {
-	const proxiedPost = $.post;
-	const proxiedGet = $.get;
+document.addEventListener("DOMContentLoaded", function() {
+	// 1. Keep the original methods bound to the jQuery ($) object
+	const originalPost = $.post.bind($);
+	const originalGet = $.get.bind($);
 
 	/** Proxied `$.post` that invokes registered interceptors before the real call. */
-	$.post = function() {
-		for (const { url, callback } of postIntercepts) {
-			if (arguments[0].endsWith(url)) {
-				callback(arguments);
+	$.post = function(this: typeof $, ...args: unknown[]): JQuery.jqXHR {
+		for (const { urlSuffix, interceptor } of postInterceptors) {
+			// Safely inspect jQuery settings objects without using "any"
+			const firstArg = args[0];
+			const requestUrl = typeof firstArg === "string"
+				? firstArg
+				: (firstArg && typeof firstArg === "object" && "url" in firstArg && typeof firstArg.url === "string" ? firstArg.url : null);
+
+			if (typeof requestUrl === "string" && requestUrl.endsWith(urlSuffix)) {
+				// Cast the unknown array to the expected tuple type
+				interceptor(args as unknown as JQueryAjaxArgs);
 			}
 		}
 
-		return proxiedPost.apply(this, Array.from(arguments) as any);
-	};
+		// Use our strict signature instead of `Function` to satisfy ESLint
+		return (originalPost as unknown as OriginalJQueryAjaxMethod)(...args);
+	} as typeof $.post; // Reassert the original type so external consumers see the normal signature
+
 	/** Proxied `$.get` that invokes registered interceptors before the real call. */
-	$.get = function() {
-		for (const { url, callback } of getIntercepts) {
-			if (arguments[0].endsWith(url)) {
-				callback(arguments);
+	$.get = function(this: typeof $, ...args: unknown[]): JQuery.jqXHR {
+		for (const { urlSuffix, interceptor } of getInterceptors) {
+			const firstArg = args[0];
+			const requestUrl = typeof firstArg === "string"
+				? firstArg
+				: (firstArg && typeof firstArg === "object" && "url" in firstArg && typeof firstArg.url === "string" ? firstArg.url : null);
+
+			if (typeof requestUrl === "string" && requestUrl.endsWith(urlSuffix)) {
+				interceptor(args as unknown as JQueryAjaxArgs);
 			}
 		}
 
-		return proxiedGet.apply(this, Array.from(arguments) as any);
-	};
+		return (originalGet as unknown as OriginalJQueryAjaxMethod)(...args);
+	} as typeof $.get;
 });
 
 /**
  * Registers a callback that fires whenever a jQuery POST request matches
  * the given URL suffix.
  *
- * @param url      - The URL suffix to match (checked via `endsWith`).
- * @param callback - Receives the original `arguments` from `$.post`.
+ * @param urlSuffix   - The URL suffix to match (checked via `endsWith`).
+ * @param interceptor - Receives the original `arguments` from `$.post`.
  */
-export function interceptPost(url: string, callback: InterceptJqueryAjaxCallback) {
-	postIntercepts.push({ url, callback });
-};
+export function addPostInterceptor(urlSuffix: string, interceptor: JQueryAjaxInterceptor): void {
+	postInterceptors.push({ urlSuffix, interceptor });
+}
 
 /**
  * Registers a callback that fires whenever a jQuery GET request matches
  * the given URL suffix.
  *
- * @param url      - The URL suffix to match (checked via `endsWith`).
- * @param callback - Receives the original `arguments` from `$.get`.
+ * @param urlSuffix   - The URL suffix to match (checked via `endsWith`).
+ * @param interceptor - Receives the original `arguments` from `$.get`.
  */
-export function interceptGet(url: string, callback: InterceptJqueryAjaxCallback) {
-	getIntercepts.push({ url, callback });
-};
+export function addGetInterceptor(urlSuffix: string, interceptor: JQueryAjaxInterceptor): void {
+	getInterceptors.push({ urlSuffix, interceptor });
+}
diff --git a/src/shared/modify-dom.ts b/src/shared/modify-dom.ts
index b268ae2..41e8730 100644
--- a/src/shared/modify-dom.ts
+++ b/src/shared/modify-dom.ts
@@ -2,7 +2,7 @@ import { observeDOM } from "@/shared/observe-dom";
 
 type DOMReplacements = {
 	innerHTML?: string;
-	[key: string]: string | undefined | null;
+	[key: string]: string | undefined | null
 };
 type DOMModificaitonRule = readonly [string, DOMReplacements];
 type DOMModificationRules = (DOMModificaitonRule | null)[];
@@ -17,23 +17,25 @@ let domModificationFinishedCount = 0;
  */
 observeDOM(() => {
 	for (let i = 0; i < domModificationRules.length; i++) {
-		if (domModificationRules[i]) {
-			const element = document.querySelector(domModificationRules[i]![0]) as HTMLElement | null;
+		const rule = domModificationRules[i];
+		if (rule?.[0]) {
+			const element = document.querySelector(rule[0]);
 
 			if (element) {
-				const attributes = domModificationRules[i]![1];
+				const attributes = rule[1];
 
 				if (attributes.innerHTML) {
-					element.innerHTML = attributes.innerHTML as string;
+					element.innerHTML = attributes.innerHTML;
 				}
 
 				delete attributes.innerHTML;
 
-				for (const attribute in attributes) {
-					if (attributes[attribute] === null) {
-						element.removeAttribute(attribute);
+				for (const attributeName in attributes) {
+					const attribute = attributes[attributeName];
+					if (attribute) {
+						element.setAttribute(attributeName, attribute);
 					} else {
-						element.setAttribute(attribute, attributes[attribute] as string);
+						element.removeAttribute(attributeName);
 					}
 				}
 
@@ -59,6 +61,6 @@ observeDOM(() => {
  *
  * @param modificationRules - Array of `[selector, attributes]` rules.
  */
-export function modifyDOM(modificationRules: DOMModificationRules) {
+export function modifyDOM(modificationRules: DOMModificationRules): void {
 	domModificationRules = domModificationRules.concat(modificationRules);
 };
diff --git a/src/shared/observe-dom.ts b/src/shared/observe-dom.ts
index 6ba1db4..ee6a51f 100644
--- a/src/shared/observe-dom.ts
+++ b/src/shared/observe-dom.ts
@@ -1,6 +1,6 @@
 type ObserveDOMCallback = () => boolean;
 
-let callbacks: ObserveDOMCallback[] = [];
+const callbacks: ObserveDOMCallback[] = [];
 
 /**
  * Starts a MutationObserver on the document that invokes each
@@ -11,9 +11,8 @@ let callbacks: ObserveDOMCallback[] = [];
 const observer = new MutationObserver(() => {
 	for (let i = 0; i < callbacks.length; i++) {
 		const callback = callbacks[i];
-		if (callback && callback()) {
+		if (callback())
 			callbacks.splice(i, 1);
-		}
 
 		if (callbacks.length <= 0) {
 			observer.disconnect();
@@ -36,6 +35,6 @@ observer.observe(document, {
  *
  * @param callback - Function that returns `true` when done.
  */
-export function observeDOM(callback: ObserveDOMCallback) {
+export function observeDOM(callback: ObserveDOMCallback): void {
 	callbacks.push(callback);
 };
diff --git a/src/shared/ocr-request.ts b/src/shared/ocr-request.ts
new file mode 100644
index 0000000..3109771
--- /dev/null
+++ b/src/shared/ocr-request.ts
@@ -0,0 +1,13 @@
+export type OCRRequest = {
+	type: "OFFSCREEN_OCR_REQUEST" | "OCR";
+	dataURL: string
+};
+
+export type OCRResponse = {
+	success: true;
+	text: string;
+	confidence: number
+} | {
+	success: false;
+	error: string
+};
diff --git a/src/shared/script-injector.ts b/src/shared/script-injector.ts
index 16cb17c..3422bab 100644
--- a/src/shared/script-injector.ts
+++ b/src/shared/script-injector.ts
@@ -1,6 +1,4 @@
-type DataType = {
-	[key: string]: string
-};
+type DataType = Record<string, string>;
 
 /**
  * Injects a `<script>` element into the document head (or `<html>`) with
@@ -11,11 +9,11 @@ type DataType = {
  * @param src  - The extension-relative script path.
  * @param data - Optional key/value pairs to set as `data-*` attributes.
  */
-export function injectScriptHead(src: string, data: DataType = {}) {
-	const s = document.createElement("script") as HTMLScriptElement;
+export function injectScriptHead(src: string, data: DataType = {}): void {
+	const s = document.createElement("script");
 	s.src = chrome.runtime.getURL(src);
 	for (const i in data) {
 		s.setAttribute(`data-${i}`, data[i]);
 	}
-	(document.head || document.documentElement).append(s);
+	document.head.append(s);
 };
diff --git a/src/shared/styling.ts b/src/shared/styling.ts
index b19ace4..57a39f6 100644
--- a/src/shared/styling.ts
+++ b/src/shared/styling.ts
@@ -5,12 +5,12 @@
  * @param selector - CSS selector string.
  * @param styles   - A map of CSS property names to values.
  */
-export function styles(selector: string, styles: Record<string, string>) {
-	const  elements = Array.from(document.querySelectorAll(selector)) as HTMLElement[];
+export function styles(selector: string, styles: Record<string, string>): void {
+	const elements = Array.from(document.querySelectorAll(selector));
 
 	for (const element of elements) {
 		for (const styleType in styles) {
-			element.style[styleType as any] = styles[styleType];
+			(element as HTMLElement).style.setProperty(styleType, styles[styleType]);
 		}
 	}
 };