The environment variable value to check.
true if the given environment variable is a non-empty string, otherwise false.
This function is specifically designed for checking process.env variables.
An environment variable is considered "defined" if it exists (is not undefined)
and its value is a non-empty string. An empty string ("") is treated as
"not defined" in this context, as is common for environment flags.
# Setting environment variables
env SOME_VAR="hello"
env EMPTY_VAR=""
Now, we can use isEnvDefined to check if an environment variable is defined
and has a non-empty string value.
// Checking environment variables
isEnvDefined(process.env.SOME_VAR); // true
isEnvDefined(process.env.EMPTY_VAR); // false
// Environment variable `UNDEFINED_VAR` is not set yet
isEnvDefined(process.env.UNDEFINED_VAR); // false
let myEnvVar: string | undefined = process.env.MY_FLAG;
if (isEnvDefined(myEnvVar)) {
// myEnvVar is now safely typed as 'string' in this scope
console.log(`My flag is set to: ${myEnvVar}`);
}
isNonNullish - Use this function to check if a value is "non-nullish".
Checks if an environment variable is defined and has a non-empty string value.