Add slide examples

Author: jessealama

tests/equals.test.js

@@ -340,3 +340,9 @@ describe("examples from the General Decimal Arithmetic specification", () => {
         });
     });
 });
+
+describe("examples from a presentation at TC39 plenary", () => {
+    test("NaN with a payload", () => {
+        expect(new Decimal128("NaN").equals(new Decimal128("NaN123"))).toStrictEqual(true);
+    });
+});

tests/lessthan.test.js

@@ -53,16 +53,16 @@ describe("lessThan", () => {
             new Decimal128("0.037").lessThan(new Decimal128("0.037037037037"))
         ).toStrictEqual(true);
     });
-    describe("examples from a presentation", () => {
+    describe("examples from a presenation", () => {
         let a = new Decimal128("1.00");
         let b = new Decimal128("1.0000");
         let c = new Decimal128("1.0001");
         let d = new Decimal128("0.9999");
         test("use mathematical equality by default", () => {
-            expect(a.lessThan(b)).toStrictEqual(false);
+            expect(b.lessThan(a)).toStrictEqual(false);
         });
         test("take trailing zeroes into account", () => {
-            expect(a.lessThan(b, { total: true })).toStrictEqual(false);
+            expect(b.lessThan(a, { total: true })).toStrictEqual(true);
         });
         test("mathematically distinct", () => {
             expect(a.lessThan(c)).toStrictEqual(true);

tests/round.test.js

@@ -459,3 +459,17 @@ describe("floor", function () {
         ).toStrictEqual("-Infinity");
     });
 });
+
+describe ("examples for TC39 plenary slides", () => {
+    let a = new Decimal128("1.456");
+    test("round to 2 decimal places, rounding mode is ceiling", () => {
+        expect(a.round(2, "ceil").toString()).toStrictEqual("1.46");
+    });
+    test("round to 1 decimal place, rounding mode unspecified", () => {
+        expect(a.round(1).toString()).toStrictEqual("1.4");
+        expect(a.round(1, "halfEven").toString()).toStrictEqual("1.4");
+    });
+    test("round to 0 decimal places, rounding mode is floor", () => {
+        expect(a.round(0, "floor").toString()).toStrictEqual("1");
+    });
+});