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); }