envOr

Signature

function envOr(
  string calldata key,
  bool defaultValue
) external returns (bool value);
function envOr(
  string calldata key,
  uint256 defaultValue
) external returns (uint256 value);
function envOr(
  string calldata key,
  int256 defaultValue
) external returns (int256 value);
function envOr(
  string calldata key,
  address defaultValue
) external returns (address value);
function envOr(
  string calldata key,
  bytes32 defaultValue
) external returns (bytes32 value);
function envOr(
  string calldata key,
  string calldata defaultValue
) external returns (string memory value);
function envOr(
  string calldata key,
  bytes calldata defaultValue
) external returns (bytes memory value);

function envOr(
  string calldata key,
  string calldata delimiter,
  bool[] calldata defaultValue
) external returns (bool[] memory value);
function envOr(
  string calldata key,
  string calldata delimiter,
  uint256[] calldata defaultValue
) external returns (uint256[] memory value);
function envOr(
  string calldata key,
  string calldata delimiter,
  int256[] calldata defaultValue
) external returns (int256[] memory value);
function envOr(
  string calldata key,
  string calldata delimiter,
  address[] calldata defaultValue
) external returns (address[] memory value);
function envOr(
  string calldata key,
  string calldata delimiter,
  bytes32[] calldata defaultValue
) external returns (bytes32[] memory value);
function envOr(
  string calldata key,
  string calldata delimiter,
  string[] calldata defaultValue
) external returns (string[] memory value);
function envOr(
  string calldata key,
  string calldata delimiter,
  bytes[] calldata defaultValue
) external returns (bytes[] memory value);

Description

A non-failing way to read an environment variable of any type: if the requested environment key does not exist, envOr() will return a default value instead of reverting (works with arrays too).

The returned type is determined by the type of defaultValue parameter passed.

Tips

• Use envOr(key, defaultValue) to read a single value
• Use envOr(key, delimiter, defaultValue[]) to read an array with delimiter
• The parsing of the environment variable will be done according to the type of defaultValue (e.g. if the default value type is uint - the environment variable will be also parsed as uint)
• Use explicit casting for literals to specify type of default variable: uint(69) will return an uint but int(69) will return an int
• Same with: string("") and bytes("") - these will return string and bytes accordingly
• Use dynamic arrays (bool[]) instead of fixed-size arrays (bool[4]) when providing default values (only dynamic arrays are supported)

Examples

Single Value

If the environment variable FORK is not set, you can specify it to be false by default:

bool fork = vm.envOr("FORK", false);

or

address owner;

function setUp() {
  owner = vm.envOr("OWNER", address(this));
}

Array

If the environment variable BAD_TOKENS is not set, you can specify the default to be an empty array:

address[] badTokens;

function envBadTokens() public {
  badTokens = vm.envOr("BAD_TOKENS", ",", badTokens);
}

or

function envBadTokens() public {
  address[] memory defaultBadTokens = new address[](0);
  address[] memory badTokens = vm.envOr("BAD_TOKENS", ",", defaultBadTokens);
}