Vitest and Rollup

Dipend integrates cleanly with modern development tools like Vitest for testing and Rollup for bundling. This guide walks you through how to configure each.

Using Vitest for Testing

Vitest is a fast unit test framework built on top of Vite, with first-class TypeScript support.

Install Vitest and Related Tools

npm install --save-dev vitest @vitest/ui @rollup/plugin-typescript ts-patch

Initialize Dipend

If not already done:

npx dipend init

Example Vitest Configuration

Create or edit a file called vitest.config.ts:

vitest.config.ts

import { defineConfig } from "vitest/config";
import tsPlugin from "@rollup/plugin-typescript";
const tspCompiler = require("ts-patch/compiler");

export default defineConfig({
  test: {
    coverage: {
      enabled: true,
      exclude: ["**/node_modules/**", "**/vitest.config.ts", "**/dist/**"],
    },
  },
  server: {
    host: "127.0.0.1",
  },
  plugins: [tsPlugin({ typescript: tspCompiler })],
});

Writing a Simple Test

Create a test like this:

greeter.test.ts

import { describe, it, expect, vi } from "vitest";
import { DependencyContainer } from "dipend";
import { Greeter } from "./greeter";
import { ILogger } from "./logger";

describe("Greeter", () => {
  const dependencyContainer = new DependencyContainer();

  afterEach(() => {
    vi.restoreAllMocks();
    dependencyContainer.reset(); // clean the container
  });

  it("greets with a name", () => {
    const logger: ILogger = { info: vi.fn() };

    dependencyContainer.addSingletonInstance<ILogger>({ instance: logger });
    dependencyContainer.addSingleton<Greeter>();

    const greeter = dependencyContainer.getDependency<Greeter>();

    expect(greeter.greet("Alice")).toBe("Hello, Alice!");
    expect(logger.info).toHaveBeenCalledWith("Hello, Alice!");
  });
});

Run Tests

npx vitest run

Or with UI:

npx vitest --ui

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Using Rollup for Bundling

Rollup is a modern bundler ideal for building TypeScript libraries and applications.

Install Rollup

npm install --save-dev rollup @rollup/plugin-typescript ts-patch

Initialize Dipend

If not already done:

npx dipend init

Basic Rollup Configuration

Create a rollup.config.js file:

rollup.config.js

import typescript from "@rollup/plugin-typescript";
const tspCompiler = require("ts-patch/compiler");

export default {
  input: "./index.ts",
  output: {
    dir: "dist",
    format: "esm",
    sourcemap: true,
  },
  plugins: [typescript({ typescript: tspCompiler })],
};

Build with Rollup

npx rollup -c

This will bundle your application or library into the dist folder.

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You’re now set up for a full development workflow using Dipend, Vitest, and Rollup!