Strict done!!

overlord/src/app/ledger/ledger.component.ts

@@ -1,5 +1,5 @@
 import { AfterViewInit, Component, ElementRef, OnInit, ViewChild } from '@angular/core';
-import { FormBuilder, FormGroup } from '@angular/forms';
+import { FormBuilder, FormControl, FormGroup } from '@angular/forms';
 import { MatAutocompleteSelectedEvent } from '@angular/material/autocomplete';
 import { MatPaginator } from '@angular/material/paginator';
 import { MatSort } from '@angular/material/sort';
@@ -25,13 +25,13 @@ export class LedgerComponent implements OnInit, AfterViewInit {
   @ViewChild('accountElement', { static: true }) accountElement?: ElementRef;
   @ViewChild(MatPaginator, { static: true }) paginator?: MatPaginator;
   @ViewChild(MatSort, { static: true }) sort?: MatSort;
-  dataSource: LedgerDataSource;
+  info: Ledger = new Ledger();
+  dataSource: LedgerDataSource = new LedgerDataSource(this.info.body);
   form: FormGroup;
-  info: Ledger;
-  selectedRowId: string;
-  debit: number;
-  credit: number;
-  running: number;
+  selectedRowId = '';
+  debit = 0;
+  credit = 0;
+  running = 0;
   /** Columns displayed in the table. Columns IDs can be added, removed, or reordered. */
   displayedColumns = ['date', 'particulars', 'type', 'narration', 'debit', 'credit', 'running'];
 
@@ -51,7 +51,7 @@ export class LedgerComponent implements OnInit, AfterViewInit {
       account: '',
     });
 
-    this.accounts = this.form.get('account').valueChanges.pipe(
+    this.accounts = (this.form.get('account') as FormControl).valueChanges.pipe(
       startWith(null),
       map((x) => (x !== null && x.length >= 1 ? x : null)),
       debounceTime(150),
@@ -71,18 +71,18 @@ export class LedgerComponent implements OnInit, AfterViewInit {
         startDate: moment(this.info.startDate, 'DD-MMM-YYYY').toDate(),
         finishDate: moment(this.info.finishDate, 'DD-MMM-YYYY').toDate(),
       });
-      this.dataSource = new LedgerDataSource(this.paginator, this.sort, this.info.body);
+      this.dataSource = new LedgerDataSource(this.info.body, this.paginator, this.sort);
     });
   }
 
   ngAfterViewInit() {
     setTimeout(() => {
-      this.accountElement.nativeElement.focus();
+      if (this.accountElement) this.accountElement.nativeElement.focus();
     }, 0);
   }
 
-  displayFn(account?: Account): string | undefined {
-    return account ? account.name : undefined;
+  displayFn(account?: Account): string {
+    return account ? account.name : '';
   }
 
   calculateTotals() {
@@ -124,11 +124,11 @@ export class LedgerComponent implements OnInit, AfterViewInit {
   getInfo(): Ledger {
     const formModel = this.form.value;
 
-    return {
+    return new Ledger({
       account: formModel.account,
       startDate: moment(formModel.startDate).format('DD-MMM-YYYY'),
       finishDate: moment(formModel.finishDate).format('DD-MMM-YYYY'),
-    };
+    });
   }
 
   exportCsv() {