Troubleshooting Vertex Protocol SDK Import Error In NodeJS TypeScript

by StackCamp Team 70 views

Introduction

This article addresses a common issue encountered when importing the Vertex Protocol SDK into a NodeJS TypeScript project. The error, Error: Cannot find module '/home/and/Desktop/code/bera-vertex-esm-fresh/node_modules/@vertex-protocol/client/dist/createVertexClient', often arises after installing the necessary packages and attempting to import modules from the SDK. This article delves into the root cause of the problem, provides a detailed explanation, and offers a step-by-step solution to resolve the error, ensuring a smooth integration of the Vertex Protocol SDK into your NodeJS TypeScript project.

Problem Description

When working with NodeJS and TypeScript, developers may encounter difficulties importing modules from the Vertex Protocol SDK. This issue typically manifests as an ERR_MODULE_NOT_FOUND error, indicating that the module specified in the import statement cannot be located. The error message often includes a path to the module within the node_modules directory, suggesting that the module is indeed present but not being resolved correctly. Specifically, the error message looks like this:

Error: Cannot find module '/home/and/Desktop/code/bera-vertex-esm-fresh/node_modules/@vertex-protocol/client/dist/createVertexClient' imported from /home/and/Desktop/code/bera-vertex-esm-fresh/node_modules/@vertex-protocol/client/dist/index.js
    at finalizeResolution (node:internal/modules/esm/resolve:274:11)
    at moduleResolve (node:internal/modules/esm/resolve:859:10)
    at defaultResolve (node:internal/modules/esm/resolve:983:11)
    at ModuleLoader.defaultResolve (node:internal/modules/esm/loader:801:12)
    at ModuleLoader.#cachedDefaultResolve (node:internal/modules/esm/loader:725:25)
    at ModuleLoader.#resolveAndMaybeBlockOnLoaderThread (node:internal/modules/esm/loader:760:38)
    at ModuleLoader.resolveSync (node:internal/modules/esm/loader:783:52)
    at ModuleLoader.#cachedResolveSync (node:internal/modules/esm/loader:744:25)
    at ModuleLoader.getModuleJobForRequire (node:internal/modules/esm/loader:462:50)
    at ModuleJobSync.#link (node:internal/modules/esm/module_job:436:34) {
  code: 'ERR_MODULE_NOT_FOUND',
}

This error typically occurs in projects using ESM (ECMAScript Modules) syntax, especially after a library has transitioned from CommonJS to ESM. The core issue stems from how ESM handles import specifiers, particularly the requirement for file extensions in relative imports. Let's delve deeper into the causes and solutions.

Detailed Explanation of the Issue

When a NodeJS project is configured to use ESM, the import statements must explicitly include the file extension (e.g., .js, .ts) for relative imports. This is a key difference from CommonJS, where file extensions are often omitted. The Vertex Protocol SDK, in its recent versions, has migrated to ESM, which necessitates adherence to this rule. The error arises because the SDK's internal import statements within its distributed JavaScript files (dist directory) might lack the necessary .js extensions.

For example, in the dist/index.js file of the @vertex-protocol/client package, you might find an export statement like this:

export * from './createVertexClient';

This statement is valid in CommonJS but problematic in ESM. To be ESM-compliant, it should be:

export * from './createVertexClient.js';

The absence of the .js extension causes NodeJS to fail to resolve the module, leading to the ERR_MODULE_NOT_FOUND error. This issue can cascade through multiple files within the SDK, each missing extension causing a new error. This can be incredibly frustrating, especially when you're setting up a new project or integrating the SDK for the first time. Understanding this fundamental difference between CommonJS and ESM is crucial for effectively troubleshooting import errors in modern NodeJS projects.

Steps to Reproduce the Error

To illustrate the problem, follow these steps to reproduce the error in a new NodeJS TypeScript project:

  1. Initialize a New Project: Create a new directory for your project and initialize a NodeJS project with npm init -y. This will generate a package.json file with default settings.

    mkdir bera-vertex-esm-fresh
cd bera-vertex-esm-fresh
npm init -y

  2. Install Dependencies: Install the necessary dependencies, including the @vertex-protocol/client, viem, and bignumber.js packages.

    npm install @vertex-protocol/client viem bignumber.js

  3. Set Up TypeScript: Install TypeScript and ts-node as development dependencies. ts-node allows you to execute TypeScript files directly.

    npm install -D typescript ts-node@latest

  4. Create a tsconfig.json File: Create a tsconfig.json file in the root of your project to configure TypeScript compilation. A basic configuration might look like this:

    {
  "compilerOptions": {
    "target": "es2022",
    "module": "esnext",
    "moduleResolution": "node",
    "esModuleInterop": true,
    "forceConsistentCasingInFileNames": true,
    "strict": true,
    "skipLibCheck": true,
    "outDir": "dist"
  }
}

  5. Create a TypeScript File: Create a TypeScript file (e.g., index.ts) and attempt to import the createVertexClient function from the @vertex-protocol/client.

    // index.ts
import { createVertexClient } from "@vertex-protocol/client";

console.log("Vertex client imported");

  6. Run the TypeScript File: Execute the TypeScript file using ts-node.

    npx ts-node index.ts

    At this point, you should encounter the ERR_MODULE_NOT_FOUND error, confirming the issue with module resolution in ESM.

By following these steps, you can reliably reproduce the error, which is crucial for understanding and verifying the effectiveness of the solutions.

Solution

The most straightforward solution is to ensure that all import specifiers within the @vertex-protocol/client package include the .js extension. Since directly modifying files within node_modules is not recommended (as changes will be overwritten during updates), a more sustainable approach is needed. There are several ways to address this issue:

1. Patching the Package

One effective method is to use a tool like patch-package to apply a patch to the @vertex-protocol/client package. This allows you to make the necessary changes directly within the node_modules directory and persist those changes across installations.

  1. Install patch-package: Add patch-package as a development dependency to your project.

    npm install --save-dev patch-package

  2. Modify the Files: Navigate to the node_modules/@vertex-protocol/client/dist directory and manually add the .js extension to all import and export statements. This involves editing files like index.js and any other files that have extension-less imports.

    For example, change:

    export * from './createVertexClient';

    to:

    export * from './createVertexClient.js';

    Repeat this for all similar import/export statements across the relevant files.

  3. Create a Patch: Run patch-package to create a patch file that captures your changes.

    npx patch-package @vertex-protocol/client

    This command generates a .patch file in the patches directory at the root of your project. This file contains the diff of your changes.

  4. Configure postinstall Script: Add a postinstall script to your package.json to automatically apply the patch after each npm install.

    {
  "scripts": {
    "postinstall": "patch-package"
  }
}

    Now, every time you run npm install, the patch will be applied, ensuring your changes persist.

2. Using moduleNameMapper in jest.config.js (If Using Jest)

If you are using Jest for testing, you can leverage the moduleNameMapper configuration option to map module requests without extensions to their .js counterparts. This approach is particularly useful for test environments.

  1. Install Jest: If you haven't already, install Jest as a development dependency.

    npm install --save-dev jest ts-jest @types/jest

  2. Configure Jest: Create a jest.config.js file in the root of your project and add the moduleNameMapper configuration.

    // jest.config.js
module.exports = {
  preset: 'ts-jest/presets/js-with-ts-esm',
  moduleNameMapper: {
    '^@vertex-protocol/client/(.*){{content}}#39;: '<rootDir>/node_modules/@vertex-protocol/client/dist/$1.js',
  },
};

    This configuration tells Jest to resolve module requests from @vertex-protocol/client by appending .js to the file path.

  3. Update tsconfig.json for Jest: Ensure your tsconfig.json is configured to support Jest. You might need to adjust the module and moduleResolution options.

    {
  "compilerOptions": {
    "target": "es2022",
    "module": "esnext",
    "moduleResolution": "node",
    "esModuleInterop": true,
    "forceConsistentCasingInFileNames": true,
    "strict": true,
    "skipLibCheck": true,
    "outDir": "dist",
    "allowSyntheticDefaultImports": true // Required for some Jest setups
  },
  "include": ["src", "test"],
  "exclude": ["node_modules"]
}

3. Awaiting SDK Update

Another approach is to monitor the @vertex-protocol/client package for updates. The maintainers may address this issue in a future release by ensuring that all internal imports include the .js extension. This is the most sustainable solution in the long run, as it eliminates the need for manual patching or workarounds.

  • Check for Updates: Regularly check the package's release notes or repository for updates related to ESM compatibility.
  • Engage with the Community: If the issue persists, consider reaching out to the maintainers or community through the project's issue tracker or discussion forums. Your feedback can help prioritize the fix.

4. Rollback to a Previous Version (Temporary Solution)

As a temporary measure, you could revert to a previous version of the @vertex-protocol/client package that uses CommonJS. However, this should be considered a short-term fix, as you'll miss out on any new features or bug fixes in the latest versions.

  1. Identify a Stable Version: Determine the last version of the package that used CommonJS.

  2. Install the Specific Version: Install that version using npm install.

    npm install @vertex-protocol/client@<version>

    Replace <version> with the specific version number.

Choosing the Right Solution

  • Patching: Best for immediate fixes and maintaining compatibility with the latest version.
  • moduleNameMapper: Ideal for test environments using Jest.
  • Awaiting SDK Update: The most sustainable long-term solution.
  • Rollback: A temporary fix to unblock development but not recommended for production.

Step-by-Step Guide to Implementing the Patching Solution

Given the effectiveness and immediate applicability of the patching solution, let's walk through the steps in detail.

Step 1: Install patch-package

First, install patch-package as a development dependency.

npm install --save-dev patch-package

This command adds patch-package to your project's devDependencies in package.json.

Step 2: Modify the Files in node_modules

Next, navigate to the node_modules/@vertex-protocol/client/dist directory and manually add the .js extension to all relevant import and export statements. This step requires careful attention to detail to ensure all necessary changes are made.

  1. Navigate to the Directory:

    cd node_modules/@vertex-protocol/client/dist

  2. Edit index.js: Open index.js in a text editor and modify any export statements that are missing the .js extension.

    For example, change:

    export * from './createVertexClient';

    to:

    export * from './createVertexClient.js';

  3. Check Other Files: Inspect other files in the dist directory, such as client.js, constants.js, and any other modules that might have similar import/export statements. Apply the same fix to these files.

    // Example in client.js
export * from './apis/context'; // Original
export * from './apis/context.js'; // Modified

Step 3: Create a Patch File

After modifying the files, create a patch file using patch-package. This command captures the changes you've made.

npx patch-package @vertex-protocol/client

This command generates a .patch file in the patches directory at the root of your project. The file is named something like patches/@vertex-protocol+client+1.14.0.patch.

Step 4: Configure the postinstall Script

To ensure the patch is applied automatically after each npm install, add a postinstall script to your package.json.

  1. Open package.json: Open your project's package.json file in a text editor.

  2. Add the postinstall Script: Add the following script to the scripts section:

    {
  "scripts": {
    "postinstall": "patch-package"
  }
}

    The scripts section should now look something like this:

    {
  "name": "bera-vertex-esm-fresh",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "postinstall": "patch-package"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "patch-package": "^8.0.0"
  },
  "dependencies": {
    "@vertex-protocol/client": "^1.14.0",
    "bignumber.js": "^9.4.0",
    "viem": "^1.6.7"
  }
}

Step 5: Test the Patch

To verify that the patch is applied correctly, run npm install again. This will trigger the postinstall script and apply the patch.

npm install

Check the console output for messages from patch-package indicating that the patch was applied successfully.

Step 6: Run Your Application

Now, try running your application or test suite again. The ERR_MODULE_NOT_FOUND error should be resolved, and your application should be able to import modules from the @vertex-protocol/client package correctly.

By following these steps, you can effectively patch the @vertex-protocol/client package and resolve the ESM import issue. This solution ensures that your project can continue to use the latest version of the SDK without encountering module resolution errors.

Conclusion

In summary, the ERR_MODULE_NOT_FOUND error when importing the Vertex Protocol SDK in a NodeJS TypeScript project is typically due to missing .js extensions in import specifiers within the SDK's ESM distribution. To resolve this, you can use patch-package to apply a patch that adds the necessary extensions, configure moduleNameMapper in Jest for testing environments, await an SDK update from the maintainers, or temporarily roll back to a previous version. The patching solution, as detailed in the step-by-step guide, offers an immediate and sustainable fix, ensuring smooth integration of the Vertex Protocol SDK into your project. Remember to stay updated with the SDK's releases and engage with the community to address any further issues. By understanding the nuances of ESM and employing these solutions, you can overcome import challenges and focus on building robust applications with the Vertex Protocol.