Check if the 9*9 Matrix grid is valid sudoku solution.

sudoku_validator.js

const validGrid =  [[8,3,5,4,1,6,9,2,7],
                    [2,9,6,8,5,7,4,3,1],
                    [4,1,7,2,9,3,6,5,8],
                    [5,6,9,1,3,4,7,8,2],
                    [1,2,3,6,7,8,5,4,9],
                    [7,4,8,5,2,9,1,6,3],
                    [6,5,2,7,8,1,3,9,4],
                    [9,8,1,3,4,5,2,7,6],
                    [3,7,4,9,6,2,8,1,5]];

const invalidGrid =[[8,3,5,4,1,6,9,2,7],
                    [2,9,6,8,5,7,4,3,1],
                    [4,1,7,2,9,3,6,5,8],
                    [5,6,9,1,3,4,7,8,2],
                    [1,2,3,6,7,8,5,4,9],
                    [7,4,8,5,2,9,1,6,3],
                    [6,5,2,7,8,1,3,9,4],
                    [9,8,1,3,4,5,2,7,6],
                    [3,7,4,9,6,2,8,1,1]];
 

function flatten(array) {
	return array.reduce((acc, sub) => (Array.isArray(sub)? acc.concat(flatten(sub)) : acc.concat(sub)), []);
}

function getArray(grid, rowLowerBound, rowUpperBound, columnLowBound, columnBound) {
	return grid.filter((row, index) => index >= rowLowerBound && index < rowUpperBound).map((row) => row.filter((item, index) => index >= columnLowBound && index < columnBound))
}

function getColumnFromGrid(grid, columnIndex) {
	return grid.map((row) => row[columnIndex])
}

function getRowFromGrid(grid, rowIndex) {
	return grid[rowIndex]
}

function validateSudokuRow(row) {
   const currentRow = row.slice(0).sort();
    for(let index = 0; index < currentRow.length; index++) {
        if(currentRow[index] !== (index + 1)) {
	    console.error('Error in array', Temprow)
            return false;
        }
    }
    return true;
}


function validateGrid(grid) {
	
	//validate rows and columns
	for(let index = 0; index < grid.length; index++) {
		if(!validateSudokuRow(getRowFromGrid(grid, index))) { console.log('Row', index + 1); return false;}
		if(!validateSudokuRow(getColumnFromGrid(grid, index))) { console.log('Column', index + 1); return false;}
	}

	// validate 3*3 squares
    for(let rowBound = 3; rowBound < 10; rowBound = rowBound + 3){
	for(let colBound = 3; colBound < 10; colBound = colBound + 3){
            if(!validateSudokuRow(flatten(getArray(grid, rowBound -3, rowBound, colBound - 3, colBound)))) { return false;}
		}
	}
	return true;
}

console.log(validateGrid(validGrid));