Files
gemini-cli/packages/core/src/utils/envExpansion.ts

55 lines
1.9 KiB
TypeScript

/**
* @license
* Copyright 2026 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
import { expand, type DotenvExpandOutput } from 'dotenv-expand';
/**
* Expands environment variables in a string using the provided environment record.
* Uses the standard `dotenv-expand` library to handle expansion consistently with
* other tools.
*
* Supports POSIX/Bash syntax ($VAR, ${VAR}).
* Note: Windows syntax (%VAR%) is not natively supported by dotenv-expand.
*
* @param str - The string containing environment variable placeholders.
* @param env - A record of environment variable names and their values.
* @returns The string with environment variables expanded. Missing variables resolve to an empty string.
*/
export function expandEnvVars(
str: string,
env: Record<string, string | undefined>,
): string {
if (!str) return str;
// 1. Pre-process Windows-style variables (%VAR%) since dotenv-expand only handles POSIX ($VAR).
// We only do this on Windows to limit the blast radius and avoid conflicts with other
// systems where % might be a literal character (e.g. in URLs or shell commands).
const isWindows = process.platform === 'win32';
const processedStr = isWindows
? str.replace(/%(\w+)%/g, (_, name) => env[name] ?? '')
: str;
// 2. Use dotenv-expand for POSIX/Bash syntax ($VAR, ${VAR}).
// dotenv-expand is designed to process an object of key-value pairs (like a .env file).
// To expand a single string, we wrap it in an object with a temporary key.
const dummyKey = '__GCLI_EXPAND_TARGET__';
// Filter out undefined values to satisfy the Record<string, string> requirement safely
const processEnv: Record<string, string> = {};
for (const [key, value] of Object.entries(env)) {
if (value !== undefined) {
processEnv[key] = value;
}
}
const result: DotenvExpandOutput = expand({
parsed: { [dummyKey]: processedStr },
processEnv,
});
return result.parsed?.[dummyKey] ?? '';
}