refactor: remove result pattern

Author: mkvlrn

package.json

@@ -46,8 +46,5 @@
     "tsc-files": "^1.1.4",
     "typescript": "^6.0.2",
     "vitest": "^4.1.2"
-  },
-  "dependencies": {
-    "@mkvlrn/result": "^5.0.8"
   }
 }

pnpm-lock.yaml

@@ -3,8 +3,5 @@
 import { divide } from "#/math/advanced";
 import { add } from "#/math/basic";
 
-const sum = add(1, 2);
-console.log(`1 + 2 = ${sum}`);
-
-const div = divide(10, 2);
-console.log(div.isError ? "Cannot divide by zero" : `10 / 2 = ${div.value}`);
+console.log(`1 + 2 = ${add(1, 2)}`);
+console.log(`10 / 2 = ${divide(10, 2)}`);

src/main.ts

@@ -1,38 +1,31 @@
-import { err, ok, type Result } from "@mkvlrn/result";
-
-interface TestCase<T> {
+interface TestCase {
   a: number;
   b: number;
-  expected: T;
-  display?: string | number;
+  expected: number;
+  errorMessage?: string;
 }
 
-export const addTestCases: TestCase<number>[] = [
+export const addTestCases: TestCase[] = [
   { a: 2, b: 2, expected: 4 },
   { a: 2, b: 3, expected: 5 },
   { a: 1000, b: 2000, expected: 3000 },
 ];
 
-export const subtractTestCases: TestCase<number>[] = [
+export const subtractTestCases: TestCase[] = [
   { a: 2, b: 2, expected: 0 },
   { a: 2, b: 3, expected: -1 },
   { a: 1000, b: 2000, expected: -1000 },
 ];
 
-export const multiplyTestCases: TestCase<number>[] = [
+export const multiplyTestCases: TestCase[] = [
   { a: 2, b: 2, expected: 4 },
   { a: 2, b: 3, expected: 6 },
   { a: 1000, b: 2000, expected: 2_000_000 },
 ];
 
-export const divideTestCases: TestCase<Result<number, Error>>[] = [
-  { a: 2, b: 2, expected: ok(1), display: 1 },
-  { a: 2, b: 4, expected: ok(0.5), display: 0.5 },
-  { a: 999, b: 333, expected: ok(3), display: 3 },
-  {
-    a: 2,
-    b: 0,
-    expected: err(new Error("cannot divide by zero")),
-    display: "Error: cannot divide by zero",
-  },
+export const divideTestCases: TestCase[] = [
+  { a: 2, b: 2, expected: 1 },
+  { a: 2, b: 4, expected: 0.5 },
+  { a: 999, b: 333, expected: 3 },
+  { a: 2, b: 0, expected: Number.NaN, errorMessage: "Error: cannot divide by zero" },
 ];

src/math/__fixtures__/test-cases.ts

@@ -14,12 +14,16 @@ describe("should multiply two numbers", () => {
 });
 
 describe("should divide two numbers", () => {
-  for (const { a, b, expected, display } of divideTestCases) {
-    test(`${a} ÷ ${b} = ${display}`, () => {
+  for (const { a, b, expected, errorMessage } of divideTestCases) {
+    test(`${a} ÷ ${b} = ${errorMessage ?? expected}`, () => {
       // act
-      const result = divide(a, b);
+      const act = () => divide(a, b);
       // assert
-      expect(result).toStrictEqual(expected);
+      if (typeof errorMessage === "string") {
+        expect(act).toThrow(errorMessage);
+      } else {
+        expect(act()).toStrictEqual(expected);
+      }
     });
   }
 });

src/math/advanced.test.ts

@@ -1,12 +1,10 @@
-import { err, ok, type Result } from "@mkvlrn/result";
-
 export function multiply(a: number, b: number): number {
   return a * b;
 }
 
-export function divide(a: number, b: number): Result<number, Error> {
+export function divide(a: number, b: number): number {
   if (b === 0) {
-    return err(new Error("cannot divide by zero"));
+    throw new Error("Error: cannot divide by zero");
   }
-  return ok(a / b);
+  return a / b;
 }