refactor: updating display string to show 'null' as '-' (#746)

Author: anandtiwary

projects/common/src/utilities/formatters/string/string-formatter.test.ts

@@ -4,6 +4,7 @@ describe('String formatter', () => {
   test('can convert to display string', () => {
     // tslint:disable-next-line: no-null-keyword
     expect(displayString(null)).toBe('-');
+    expect(displayString('null')).toBe('-');
     expect(displayString(undefined)).toBe('-');
     expect(displayString('')).toBe('');
     expect(displayString('value')).toBe('value');

projects/common/src/utilities/formatters/string/string-formatter.ts

@@ -1,5 +1,5 @@
 export const displayString = (provided?: unknown): string => {
-  if (provided === null) {
+  if (provided === null || provided === 'null') {
     return '-';
   }