Dynamic Imports Pattern

How It Works Modified: 2025-Dec-03 09:08:52 UTC

Problem/Solution

The pattern of dynamically importing specified modules and their functions solves several key problems:

  1. On-Demand Loading:
    • Problem: Loading all modules and their dependencies at startup can lead to increased memory usage and slower startup times.
    • Solution: By dynamically importing modules only when they are needed, this pattern reduces initial load times and memory consumption.
  2. Optimized Performance:
    • Problem: In serverless environments like Edge functions, cold start times can be significant if all dependencies are loaded upfront.
    • Solution: Dynamic imports allow for optimized performance by loading only the necessary modules at runtime, reducing cold start times.
  3. Modular and Flexible Code:
    • Problem: Hardcoding imports can make the code less flexible and harder to maintain, especially when dealing with multiple modules and dependencies.
    • Solution: This pattern promotes modularity and flexibility by allowing the code to dynamically determine which modules to load based on runtime conditions.
  4. Error Handling:
    • Problem: Importing modules that may not be available or have different versions can lead to runtime errors.
    • Solution: The pattern includes error handling to log and manage import failures gracefully, ensuring that the application can handle missing or incompatible modules.
  5. Environment-Specific Loading:
    • Problem: Different environments (Edge Functions vs. Node.js) may require different modules or configurations.
    • Solution: This pattern allows for environment-specific loading of modules. For Edge Functions, modules can be loaded based on the URL or other request-specific parameters. In typical Node.js environments, modules can be loaded based on application logic or configuration files.

Summary This dynamic import pattern addresses the need for efficient, flexible, and modular code execution, particularly in environments where performance and resource optimization are critical. It allows for on-demand loading of modules, reducing initial load times and memory usage, while also providing robust error handling to manage potential import issues.

Explanation and Diagram

Below is the complete explanation and Mermaid.js diagram, including how the modules work together to dynamically import and use OpenAI-related functions in both Edge and Node.js runtimes, and how to call performOpenAIRequest via either an Edge Function (openaiEdge.js) or via AVA tests (openaiFunctions.test.js and dynamicImports.test.js):

Explanation

  1. User Interaction:

    • The user calls the performOpenAIRequest function in openaiFunctions.js.

  2. Function Call:

    • performOpenAIRequest calls the getOpenAIImports function in openaiImports.js to get the necessary OpenAI modules.

  3. Dynamic Imports:

    • getOpenAIImports uses the initializeImports function from dynamicImports.js to dynamically import the specified modules and their functions.

  4. Return Imported Modules:

    • initializeImports dynamically imports the modules and returns them to getOpenAIImports.

  5. Return to Caller:

    • getOpenAIImports returns the imported modules (ChatOpenAI, OpenAI) to performOpenAIRequest.

Mermaid.js

Sequence Diagram

sequenceDiagram
participant User
participant openaiEdge.js
participant openaiFunctions.js
participant openaiImports.js
participant dynamicImports.js
participant openaiFunctions.test.js
participant dynamicImports.test.js

    User ->> openaiEdge.js: Call Edge Function
    openaiEdge.js ->> openaiFunctions.js: Call performOpenAIRequest(prompt)
    openaiFunctions.js ->> openaiImports.js: Call getOpenAIImports(verbose)
    openaiImports.js ->> dynamicImports.js: Call initializeImports(packageExports, verbose)
    dynamicImports.js ->> dynamicImports.js: Dynamically import modules
    dynamicImports.js -->> openaiImports.js: Return imported modules
    openaiImports.js -->> openaiFunctions.js: Return { ChatOpenAI, OpenAI }
    openaiFunctions.js -->> openaiEdge.js: Use imported modules
    openaiEdge.js -->> User: Return response

    User ->> openaiFunctions.test.js: Run AVA Test
    openaiFunctions.test.js ->> openaiFunctions.js: Call performOpenAIRequest(prompt)
    openaiFunctions.js ->> openaiImports.js: Call getOpenAIImports(verbose)
    openaiImports.js ->> dynamicImports.js: Call initializeImports(packageExports, verbose)
    dynamicImports.js ->> dynamicImports.js: Dynamically import modules
    dynamicImports.js -->> openaiImports.js: Return imported modules
    openaiImports.js -->> openaiFunctions.js: Return { ChatOpenAI, OpenAI }
    openaiFunctions.js -->> openaiFunctions.test.js: Use imported modules
    openaiFunctions.test.js -->> User: Return test result

    User ->> dynamicImports.test.js: Run AVA Test
    dynamicImports.test.js ->> dynamicImports.js: Call initializeImports(packageExports, verbose)
    dynamicImports.js ->> dynamicImports.js: Dynamically import modules
    dynamicImports.js -->> dynamicImports.test.js: Return imported modules
    dynamicImports.test.js -->> User: Return test result

Class Diagram

The openaiImports class is designed to dynamically import and initialize the necessary modules for OpenAI. This ensures that the correct versions of dependencies are used when dynamically loading modules.


classDiagram
class openaiFunctions {
+performOpenAIRequest(prompt: string)
}

    note for openaiImports "IIFE is a self-invoking, \nImmediately Invoked Function Expression \nthat calls initializeImports() when the module loads"
    class openaiImports {
        +getOpenAIImports(verbose: boolean): object
        +ChatOpenAI
        +OpenAI
        +IIFE
    }

class openaiEdge {
+default(request: Request): Promise
}

class openaiFunctionsTest {
+testPerformOpenAIRequest(): void
}

class dynamicImportsTest {
+testInitializeImports(): void
}

note for dynamicImports "See getVersionFromPackageJSON() and \nExtract Package Versions Script"
class dynamicImports {
+getVersionFromPackageJSON(packageName: string, verbose: boolean): string
+initializeImports(packageExports: object, verbose: boolean): Promise
}

openaiFunctions --> openaiImports : uses
openaiImports --> dynamicImports : uses
openaiEdge --> openaiFunctions : uses
openaiFunctionsTest --> openaiFunctions : tests
dynamicImportsTest --> dynamicImports : tests

How It Works in Both Edge and Node.js Runtimes

Edge Runtime

  • Dynamic Imports: Edge functions support dynamic imports, so initializeImports can dynamically load modules as needed.
  • Environment: Edge functions run in a serverless environment, so they need to handle imports and dependencies dynamically to optimize performance and reduce cold start times.

Node.js Runtime

  • Dynamic Imports: Node.js also supports dynamic imports, so initializeImports works similarly to load modules dynamically.
  • Environment: Node.js runs in a more traditional server environment, so dynamic imports can help manage dependencies and optimize resource usage.

Example Code

openaiFunctions.js

/**
- @file netlify/utils/experiments/openaiFunctions.js
- @module openAIFunctions
- @description
- This module provides various utility functions for interacting with OpenAI's services.
- It includes methods for processing data and handling API responses.
*/
import {
  logMsg,
  logErr,
  getEnvVar,
  hasValue,
  checkRequiredParameters,
} from "./openaiHelper.js";
import { getOpenAIImports, ChatOpenAI } from "./openaiImports.js";

const verbose = true;
const lmOptions = {
  moduleName: "openaiFunctions.js",
  verbose,
};

/**
- @name performOpenAIRequest
- @description Perform OpenAI Request
- @param {string} prompt - ChatOpenAI System prompt
- @returns
*/
export async function performOpenAIRequest(prompt) {
  const { ChatOpenAI } = getOpenAIImports(verbose);
  // Implementation here
}

openaiImports.js

/**
 * @file netlify/utils/experiments/openaiImports.js
 * @module openAIImports
 * @description
 * This module dynamically imports and initializes OpenAI-related modules.
 * It ensures that the required modules are loaded and available for use.
 */

import { initializeImports } from "./dynamicImports.js";

const caller = "openaiImports";
const verbose = true;

// Placeholder for imported modules
let ChatOpenAI = null,
  OpenAI = null;

// Self-invoking function to initialize the imports when the module loads
(async () => {
  const pkg = "@langchain/openai";
  const functions = ["ChatOpenAI", "OpenAI"];
  const packageExports = { [pkg]: functions };
  const packageImports = await initializeImports(packageExports, verbose);
  ({ ChatOpenAI, OpenAI } = packageImports[pkg]);
  console.log(
    `${caller} self-invoking ChatOpenAI: ${ChatOpenAI ? true : false}`
  );
})();

// Function to get the initialized modules (if needed by other modules)
function getOpenAIImports(verbose = false) {
  verbose ? console.log(`Calling getOpenAIImports()`) : null;
  return {
    ChatOpenAI,
    OpenAI,
  };
}

// Optional: Export the initialized modules directly for easier access
export { getOpenAIImports, ChatOpenAI, OpenAI };

dynamicImports.js

/**
 * @module dynamicImports
 * @description
 * This module provides a function to dynamically import specified modules and their functions.
 * It allows for flexible and on-demand loading of modules.
 */

/**
 * Dynamically imports the specified modules and their functions.
 * @param {object} packageExports - An object where keys are package names and values are arrays of function names to import.
 * @param {boolean} verbose - Whether to log detailed information.
 * @returns {Promise<object>} - An object containing the imported functions.
 */
export async function initializeImports(packageExports, verbose) {
  const imports = {};

  for (const [pkg, functions] of Object.entries(packageExports)) {
    try {
      const module = await import(pkg);
      imports[pkg] = {};

      for (const func of functions) {
        if (module[func]) {
          imports[pkg][func] = module[func];
          lmOptions.msg = `found imports[${pkg}]: ${func}`;
          logMsg(lmOptions);
        } else {
          throw new Error(`Function ${func} not found in package ${pkg}`);
        }
      }
    } catch (error) {
      lmOptions.msg = error.message;
      logErr(lmOptions);
      throw error;
    }
  }

  lmOptions.msg = `imports: ${hasValue(imports)}`;
  logMsg(lmOptions);

  return imports;
}

Calling performOpenAIRequest Via Edge Function (openaiEdge.js)

import { performOpenAIRequest } from "../utils/experiments/openaiFunctions.js";

export default async (request) => {
  const url = new URL(request.url);
  const prompt = url.searchParams.get("prompt");

  if (!prompt) {
    return new Response("Prompt is required", { status: 400 });
  }

  try {
    const response = await performOpenAIRequest(prompt);
    return new Response(JSON.stringify(response), {
      headers: { "Content-Type": "application/json" },
    });
  } catch (error) {
    return new Response(error.message, { status: 500 });
  }
};

Via AVA Tests (openaiFunctions.test.js)

import test from "ava";
import { performOpenAIRequest } from "../utils/experiments/openaiFunctions.js";

test("performOpenAIRequest should return a valid response", async (t) => {
  const prompt = "Hello, how are you?";
  const response = await performOpenAIRequest(prompt);

  t.truthy(response);
  t.is(typeof response, "object");
  t.truthy(response.result);
});

Via AVA Tests (dynamicImports.test.js)

import test from "ava";
import { initializeImports } from "../utils/experiments/dynamicImports.js";

test("initializeImports should dynamically import modules", async (t) => {
  const packageExports = {
    "@langchain/openai": ["ChatOpenAI", "OpenAI"],
  };
  const imports = await initializeImports(packageExports, true);

  t.truthy(imports["@langchain/openai"]);
  t.truthy(imports["@langchain/openai"].ChatOpenAI);
  t.truthy(imports["@langchain/openai"].OpenAI);
});

This setup allows for flexible and efficient loading of modules based on the runtime environment, ensuring that the necessary dependencies are available when needed. The dynamic import process enables better resource management and performance optimization in both Edge and Node.js runtimes.