Add tests for date and number formatting functions

extensions/ql-vscode/src/pure/number.ts

@@ -2,7 +2,7 @@
  * Contains an assortment of helper constants and functions for working with numbers.
  */
 
-const numberFormatter = new Intl.NumberFormat('en');
+const numberFormatter = new Intl.NumberFormat('en-US');
 
 export function formatDecimal(value: number): string {
   return numberFormatter.format(value);

extensions/ql-vscode/test/pure-tests/date.test.ts

@@ -0,0 +1,11 @@
+import { expect } from 'chai';
+import 'mocha';
+
+import { formatDate } from '../../src/pure/date';
+
+describe('Date', () => {
+  it('should return a formatted date', () => {
+    expect(formatDate(new Date(1663326904000))).to.eq('Sep 16, 1:15 PM');
+    expect(formatDate(new Date(1631783704000))).to.eq('Sep 16, 2021, 11:15 AM');
+  });
+});

extensions/ql-vscode/test/pure-tests/number.test.ts

@@ -0,0 +1,12 @@
+import { expect } from 'chai';
+import 'mocha';
+
+import { formatDecimal } from '../../src/pure/number';
+
+describe('Number', () => {
+  it('should return a formatted decimal', () => {
+    expect(formatDecimal(9)).to.eq('9');
+    expect(formatDecimal(10_000)).to.eq('10,000');
+    expect(formatDecimal(100_000_000_000)).to.eq('100,000,000,000');
+  });
+});

extensions/ql-vscode/test/pure-tests/time.test.ts

@@ -5,10 +5,13 @@ import { humanizeRelativeTime, humanizeUnit } from '../../src/pure/time';
 
 describe('Time', () => {
   it('should return a humanized unit', () => {
-    expect(humanizeUnit(undefined)).to.eq('Less than a minute');
+    expect(humanizeUnit(undefined)).to.eq('Less than a second');
-    expect(humanizeUnit(0)).to.eq('Less than a minute');
+    expect(humanizeUnit(0)).to.eq('Less than a second');
-    expect(humanizeUnit(-1)).to.eq('Less than a minute');
+    expect(humanizeUnit(-1)).to.eq('Less than a second');
-    expect(humanizeUnit(1000 * 60 - 1)).to.eq('Less than a minute');
+    expect(humanizeUnit(1000 - 1)).to.eq('Less than a second');
+    expect(humanizeUnit(1000)).to.eq('1 second');
+    expect(humanizeUnit(1000 * 2)).to.eq('2 seconds');
+    expect(humanizeUnit(1000 * 60 - 1)).to.eq('59 seconds');
     expect(humanizeUnit(1000 * 60)).to.eq('1 minute');
     expect(humanizeUnit(1000 * 60 * 2 - 1)).to.eq('1 minute');
     expect(humanizeUnit(1000 * 60 * 2)).to.eq('2 minutes');