fix: Remove unused variables and dead code across codebase

Remove unused vars, dead functions (sib, dfs, handleRefresh), unused
imports, and unused props to resolve all ESLint no-unused-vars warnings.
Also fix setState-in-effect, state mutation, and hoisting lint errors.

Author: TamimEhsan

src/app/15-puzzle/page.jsx

@@ -34,7 +34,6 @@ class Puzzle extends Component {
     }
 
     render() {
-        let classNames;
         return (
 
             <div style={{ backgroundColor: "#57407c" }}

src/app/components/footer.jsx

@@ -1,16 +1,8 @@
 'use client'
 
-import { useEffect, useState } from 'react';
 import GitHubButton from 'react-github-btn';
 
 export default function Footer() {
-  const [visitors, setVisitors] = useState(0)
-
-  useEffect(() => {
-    // Simulate fetching visitor count
-    // In a real application, you would fetch this from an API
-    setVisitors(Math.floor(Math.random() * 10000))
-  }, [])
 
   return (
     <footer className="bg-background py-6 px-6 mt-12 border-t">

src/app/convex-hull/canvas.jsx

@@ -11,16 +11,6 @@ export default function Canvas({ width, height, dots, onTurnOff, onGoing, speed
     useEffect(() => { onGoingRef.current = onGoing; }, [onGoing]);
     useEffect(() => { speedRef.current = speed; }, [speed]);
 
-    useEffect(() => {
-        redrawDots();
-    }, [dots]);
-
-    useEffect(() => {
-        if (onGoing) {
-            animateLine();
-        }
-    }, [onGoing]);
-
     const redrawDots = () => {
         const canvas = dotsCanvasRef.current;
         if (!canvas) return;
@@ -111,6 +101,16 @@ export default function Canvas({ width, height, dots, onTurnOff, onGoing, speed
         }
     };
 
+    useEffect(() => {
+        redrawDots();
+    }, [dots]);
+
+    useEffect(() => {
+        if (onGoing) {
+            animateLine();
+        }
+    }, [onGoing]);
+
     return (
         <>
             <canvas

src/app/game-of-life/page.jsx

@@ -30,15 +30,15 @@ export default function GameOfLifePage() {
         // this.setState({ mouseIsPressed: true });
     }
 
-    const handleMouseEnter = (row, col) => {
+    const handleMouseEnter = (_row, _col) => {
         // if (this.state.mouseIsPressed === false) return;
         // if ((this.state.startNode.row !== row || this.state.startNode.col !== col) && (this.state.endNode.row !== row || this.state.endNode.col !== col)) {
         //     const newGrid = getNewGridWithWallToggled(this.state.grid, row, col);
         //     this.setState({ grid: newGrid });
         // }
     }
 
-    const handleMouseUp = (row, col) => {
+    const handleMouseUp = (_row, _col) => {
         // this.setState({ mouseIsPressed: false });
     }
 
@@ -52,7 +52,6 @@ export default function GameOfLifePage() {
     const handleStop = () => {
         setRunning(false);
         runningRef.current = false;
-        console.log("Simulation stopped");
     }
 
     const handleClearBoard = () => {

src/app/n-queen/page.jsx

@@ -6,7 +6,7 @@ import Navbar from '@/components/navbar';
 import Menu from "./menu";
 
 export default function Queen() {
-    const [board, setBoard] = useState([]);
+    const [board, setBoard] = useState(() => getBoard(4));
     const [number, setNumber] = useState(4);
     const [speed, setSpeed] = useState(490);
     const [isRunning, setIsRunning] = useState(false);
@@ -17,10 +17,6 @@ export default function Queen() {
     useEffect(() => { numberRef.current = number; }, [number]);
     useEffect(() => { speedRef.current = speed; }, [speed]);
 
-    useEffect(() => {
-        setBoard(getBoard(4));
-    }, []);
-
     const handleSpeedChange = (val) => {
         setSpeed((100 - val) * 10);
     };

src/app/pathfinder/page.jsx

@@ -74,18 +74,18 @@ export default function Pathfinder() {
             default:
                 pairs = getMaze(gridCopy, row, col);
         }
-        const currentGrid = grid;
+        let currentGrid = grid.map(row => [...row]);
         for (let i = 0; i < pairs.length; i++) {
             const { xx, yy } = pairs[i];
             if ((xx !== startNode.row || yy !== startNode.col) && (xx !== endNode.row || yy !== endNode.col)) {
                 currentGrid[xx][yy] = { ...currentGrid[xx][yy], isWall: true };
-                setGrid([...currentGrid]);
+                setGrid(currentGrid.map(row => [...row]));
             }
             await sleep(20);
         }
         currentGrid[startNode.row][startNode.col] = { ...currentGrid[startNode.row][startNode.col], isWall: false };
         currentGrid[endNode.row][endNode.col] = { ...currentGrid[endNode.row][endNode.col], isWall: false };
-        setGrid([...currentGrid]);
+        setGrid(currentGrid.map(row => [...row]));
         setIsRunning(false);
     };
 
@@ -126,23 +126,23 @@ export default function Pathfinder() {
     };
 
     const animateDijkstra = async (visitedNodesInOrder, nodesInShortestPathOrder) => {
+        let currentGrid = grid.map(row => [...row]);
         for (let i = 0; i < visitedNodesInOrder.length; i++) {
             const node = visitedNodesInOrder[i];
-            const currentGrid = grid;
             currentGrid[node.row][node.col] = { ...currentGrid[node.row][node.col], isVisited: true };
-            setGrid([...currentGrid]);
+            setGrid(currentGrid.map(row => [...row]));
             await sleep(10);
         }
         await sleep(100);
         await animateShortestPath(nodesInShortestPathOrder);
     };
 
     const animateShortestPath = async (nodesInShortestPathOrder) => {
+        let currentGrid = grid.map(row => [...row]);
         for (let i = 0; i < nodesInShortestPathOrder.length; i++) {
             const node = nodesInShortestPathOrder[i];
-            const currentGrid = grid;
             currentGrid[node.row][node.col] = { ...currentGrid[node.row][node.col], ispathNode: true };
-            setGrid([...currentGrid]);
+            setGrid(currentGrid.map(row => [...row]));
             await sleep(50);
         }
         setIsRunning(false);

src/app/prime-numbers/page.jsx

@@ -9,7 +9,7 @@ import Spiral from "./spiral";
 
 export default function Seive() {
     const [number, setNumber] = useState(100);
-    const [cells, setCells] = useState([]);
+    const [cells, setCells] = useState(() => getCells(100));
     const [isRunning, setIsRunning] = useState(false);
     const [speed, setSpeed] = useState(500);
     const [primes, setPrimes] = useState([]);
@@ -22,10 +22,6 @@ export default function Seive() {
     useEffect(() => { speedRef.current = speed; }, [speed]);
     useEffect(() => { numberRef.current = number; }, [number]);
 
-    useEffect(() => {
-        setCells(getCells(100));
-    }, []);
-
     const changeSpeed = (val) => {
         setSpeed(600 - val * 10);
     };
@@ -109,7 +105,7 @@ export default function Seive() {
                     {algo === 0 && <Cells cells={cells} />}
                     {algo === 1 && (
                         <div className="h-full w-full justify-center bg-gray-700">
-                            <Spiral num={number} primes={primes} maxPrime={maxPrime} />
+                            <Spiral primes={primes} maxPrime={maxPrime} />
                         </div>
                     )}
                 </div>

src/app/prime-numbers/spiral.jsx

@@ -1,4 +1,4 @@
-export default function Spiral({ num, primes, maxPrime }) {
+export default function Spiral({ primes, maxPrime }) {
     let Maxwidth = window.innerWidth;
     let MaxHeight = window.innerHeight;
 

src/app/recursion-tree/Tree.js

@@ -113,8 +113,6 @@ function firstwalk(v, distance = 1) {
 
         let midpoint = (v.children[0].x + v.children[v.children.length-1].x) / 2;
 
-        let ell = v.children[0];
-        let arr = v.children[-1];
         let w = v.lbrother();
         if (w) {
             v.x = w.x + distance;
@@ -221,12 +219,6 @@ function second_walk(v, m = 0, depth = 0, min = undefined) {
     return min;
 }
 
-function dfs(tree){
-    if( tree.tree.node === 'B' ) return;
-    console.log( tree.tree.node, tree.x,tree.y );
-    for(let i=0;i<tree.children.length;i++)
-        dfs(tree.children[i]);
-}
 /*
 let blank = new Tree('B',[]);
 let ll = new Tree("ll",[]);

src/app/recursion-tree/fib.jsx

@@ -21,15 +21,6 @@ function fib(n){
     return tree;
 }
 
-function sib(n){
-    let tree = new Tree(n,[]);
-    if( n <3 ) return tree;
-    tree.children.push( sib(n-2) );
-    tree.children.push( sib(n-3) );
-    tree.node = tree.children[0].node+tree.children[1].node;
-    return tree;
-}
-
 function NcR(n,r){
     if (r > n)
         return new Tree(-1,[],"("+n+","+r+")");