API reference

The whole package is one file, goenv.go: three functions, three constants and one type. That’s it. There’s nothing else to find.

import "github.com/psyb0t/goenv"

Functions

Function	Returns	What it’s basically doing
`Get() Type`	`Dev` when `ENV` is exactly `"dev"`, otherwise `Prod`	`if os.Getenv("ENV") == "dev" { return "dev" } else { return "prod" }`
`IsProd() bool`	`true` unless `ENV` is exactly `"dev"`	`Get() == Prod`
`IsDev() bool`	`true` only when `ENV` is exactly `"dev"`	`Get() == Dev`

All three read the variable with os.Getenv on every call. Nothing is cached, so if your process changes ENV at runtime, the next call sees the new value. In practice set it once before the process starts and leave it alone.

None of them return an error. There is nothing that can fail.

Constants

Constant	Type	Value	Surprise level
`EnvVarName`	untyped string	`"ENV"`	None
`Prod`	`Type`	`"prod"`	None
`Dev`	`Type`	`"dev"`	None

EnvVarName is there so you can reference the name, not change it. The variable goenv reads is always ENV.

Type

type Type = string

Type is a type alias, not a new type. goenv.Type is string, so any string is assignable to it and the compiler won’t stop you comparing Get() against "staging". Prod and Dev are convenient names, not a closed enum.

Which values mean dev

Get() does one exact, case-sensitive switch on the value of ENV:

`ENV` value	`Get()`	`IsProd()`	`IsDev()`
`dev`	`dev`	`false`	`true`
`prod`	`prod`	`true`	`false`
unset	`prod`	`true`	`false`
empty	`prod`	`true`	`false`
`DEV`, `Dev`	`prod`	`true`	`false`
`development`, `staging`, `test`	`prod`	`true`	`false`
anything else	`prod`	`true`	`false`

Only the literal lowercase dev counts as dev. That’s on purpose: a missing or misspelled ENV fails safe toward production behavior instead of quietly switching on your dev-only shortcuts.

export ENV=dev   # you're developing
export ENV=prod  # you're in production
export ENV=      # also production, because paranoia is a feature

Limits

Two environments only. If you need staging, test or ci as real, separate environments, goenv can’t express it. Use a proper config library.
The variable name is fixed at ENV.
No type safety beyond string, as explained under Type.