test: Add tests for LexoDecimal

src/lexoRank/lexoDecimal.spec.ts

@@ -0,0 +1,51 @@
+import { getTestCases } from "../setupTests";
+import { LexoDecimal } from "./lexoDecimal";
+import { LexoInteger } from "./lexoInteger";
+
+test.each(getTestCases())("Parse base $base", ({ system }) => {
+  const radixPointChar = system.radixPointChar;
+
+  expect(() =>
+    LexoDecimal.parse(radixPointChar + radixPointChar, system),
+  ).toThrow(`More than one ${radixPointChar}`);
+
+  const intString = "42";
+  const int = LexoInteger.parse(intString, system);
+  expect(LexoDecimal.parse(intString, system)).toEqual(LexoDecimal.from(int));
+  expect(LexoDecimal.make(int.shiftLeft(2), 2)).toEqual(LexoDecimal.from(int));
+});
+
+test.each(getTestCases([10]))("Arithmetics base $base", ({ system, base }) => {
+  const toString = (num: number) =>
+    num.toString(base).replace(".", system.radixPointChar);
+  const _ = (num: number) =>
+    LexoDecimal.parse(toString(Number(num.toFixed(2))), system);
+
+  expect(LexoDecimal.half(system)).toEqual(_(0.5));
+
+  const nums = [4.2, 31.4, -1.9, 42];
+  const lexoDecimals = nums.map(_);
+
+  function* generatePairs() {
+    for (let i = 0; i < nums.length; ++i) {
+      for (let j = 0; j < nums.length; ++j) {
+        yield [nums[i], lexoDecimals[i], nums[j], lexoDecimals[j]] as const;
+      }
+    }
+  }
+
+  // Add
+  for (const [x, lexoX, y, lexoY] of generatePairs()) {
+    expect(lexoX.add(lexoY)).toEqual(_(x + y));
+  }
+
+  // Subtract
+  for (const [x, lexoX, y, lexoY] of generatePairs()) {
+    expect(lexoX.subtract(lexoY)).toEqual(_(x - y));
+  }
+
+  // Multiply
+  for (const [x, lexoX, y, lexoY] of generatePairs()) {
+    expect(lexoX.multiply(lexoY)).toEqual(_(x * y));
+  }
+});

src/lexoRank/lexoDecimal.ts

@@ -11,7 +11,7 @@ export class LexoDecimal {
   public static parse(str: string, system: INumeralSystem): LexoDecimal {
     const partialIndex = str.indexOf(system.radixPointChar);
     if (str.lastIndexOf(system.radixPointChar) !== partialIndex) {
-      throw new Error("More than one " + system.radixPointChar);
+      throw new Error(`More than one ${system.radixPointChar}`);
     }
 
     if (partialIndex < 0) {