loadEnv() — vite Function Reference

Architecture documentation for the loadEnv() function in env.ts from the vite codebase.

Function typescript ViteCore ConfigEngine calls 3 called by 1

Entity Profile

ViteCore→ ConfigEngine→ loadEnv() — vite Function Reference

Dependency Diagram

graph TD
  dbbbbbec_1500_ac8a_4605_9194e2cfb45d["loadEnv()"]
  7fa76fc1_cb1b_cf98_0900_1217276f6616["env.ts"]
  dbbbbbec_1500_ac8a_4605_9194e2cfb45d -->|defined in| 7fa76fc1_cb1b_cf98_0900_1217276f6616
  58c4a210_68fe_1b4d_ed49_d59203f97ef1["resolveConfig()"]
  58c4a210_68fe_1b4d_ed49_d59203f97ef1 -->|calls| dbbbbbec_1500_ac8a_4605_9194e2cfb45d
  19ce2051_6a74_4b8b_104d_ec006cd7075f["arraify()"]
  dbbbbbec_1500_ac8a_4605_9194e2cfb45d -->|calls| 19ce2051_6a74_4b8b_104d_ec006cd7075f
  ff7562f3_f396_12b1_2d0c_c03c1ee28f2c["getEnvFilesForMode()"]
  dbbbbbec_1500_ac8a_4605_9194e2cfb45d -->|calls| ff7562f3_f396_12b1_2d0c_c03c1ee28f2c
  a9bd45ce_8339_2b77_7543_41c306ebdb02["tryStatSync()"]
  dbbbbbec_1500_ac8a_4605_9194e2cfb45d -->|calls| a9bd45ce_8339_2b77_7543_41c306ebdb02
  style dbbbbbec_1500_ac8a_4605_9194e2cfb45d fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/vite/src/node/env.ts lines 27–95

export function loadEnv(
  mode: string,
  envDir: string | false,
  prefixes: string | string[] = 'VITE_',
): Record<string, string> {
  const start = performance.now()
  const getTime = () => `${(performance.now() - start).toFixed(2)}ms`

  if (mode === 'local') {
    throw new Error(
      `"local" cannot be used as a mode name because it conflicts with ` +
        `the .local postfix for .env files.`,
    )
  }
  prefixes = arraify(prefixes)
  const env: Record<string, string> = {}
  const envFiles = getEnvFilesForMode(mode, envDir)

  debug?.(`loading env files: %O`, envFiles)

  const parsed = Object.fromEntries(
    envFiles.flatMap((filePath) => {
      const stat = tryStatSync(filePath)
      // Support FIFOs (named pipes) for apps like 1Password
      if (!stat || (!stat.isFile() && !stat.isFIFO())) return []

      const parsedEnv = parseEnv(fs.readFileSync(filePath, 'utf-8'))
      return Object.entries(parsedEnv as Record<string, string>)
    }),
  )

  debug?.(`env files loaded in ${getTime()}`)

  // test NODE_ENV override before expand as otherwise process.env.NODE_ENV would override this
  if (parsed.NODE_ENV && process.env.VITE_USER_NODE_ENV === undefined) {
    process.env.VITE_USER_NODE_ENV = parsed.NODE_ENV
  }
  // support BROWSER and BROWSER_ARGS env variables
  if (parsed.BROWSER && process.env.BROWSER === undefined) {
    process.env.BROWSER = parsed.BROWSER
  }
  if (parsed.BROWSER_ARGS && process.env.BROWSER_ARGS === undefined) {
    process.env.BROWSER_ARGS = parsed.BROWSER_ARGS
  }

  // let environment variables use each other. make a copy of `process.env` so that `dotenv-expand`
  // doesn't re-assign the expanded values to the global `process.env`.
  const processEnv = { ...process.env } as DotenvPopulateInput
  expand({ parsed, processEnv })

  // only keys that start with prefix are exposed to client
  for (const [key, value] of Object.entries(parsed)) {
    if (prefixes.some((prefix) => key.startsWith(prefix))) {
      env[key] = value
    }
  }

  // check if there are actual env variables starting with VITE_*
  // these are typically provided inline and should be prioritized
  for (const key in process.env) {
    if (prefixes.some((prefix) => key.startsWith(prefix))) {
      env[key] = process.env[key] as string
    }
  }

  debug?.(`using resolved env: %O`, env)

  return env
}