Better environment value interface

[nlarew]

Changes

• Adds a new function, getEnv(), that is more precise and flexible than assertEnvVars()
  • Required vars are listed by name in a list, without the extra empty string value for each var
  • [NEW] Optional vars are listed in an object that maps to default values
• Does NOT replace any instance of assertEnvVars() or our defined env var objects. TBD in another PR

Example

const env = getEnv(
  required: ["OPENAI_ENDPOINT"],
  optional: {
    "PORT": "3000",
    "SLACK_BOT_TOKEN": undefined,
  }
);

env.OPENAI_ENDPOINT; // string
env.PORT; // string
env.SLACK_BOT_TOKEN; // string | undefined

[Copilot]

Pull Request Overview

This pull request introduces a new function, getEnv(), which provides a more precise interface for handling environment variables by allowing explicit declarations of required and optional variables.

• Adds a new getEnv() function that reads and returns environment variables from process.env
• Enhances flexibility by allowing optional variables to default to specified values
• Provides comprehensive type tests to ensure correct typing of the environment object

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

File	Description
packages/mongodb-rag-core/src/getEnv.ts	Implements the new getEnv() function with required and optional environment variable support
packages/mongodb-rag-core/src/getEnv.test.ts	Tests for validating the functional behavior of getEnv()
packages/mongodb-rag-core/src/getEnv.test-d.ts	Type tests ensuring that the inferred types of environment variables are correct