37 lines
1.2 KiB
TypeScript
37 lines
1.2 KiB
TypeScript
|
// From https://github.com/alexreardon/tiny-invariant/blob/master/src/tiny-invariant.ts
|
||
|
|
|
||
|
|
const isDenoDeploy: boolean = Deno.env.get("DENO_DEPLOYMENT_ID") !== undefined;
|
||
|
|
const prefix: string = "Invariant failed";
|
||
|
|
|
||
|
|
// Throw an error if the condition fails
|
||
|
|
// Strip out error messages for production
|
||
|
|
// > Not providing an inline default argument for message as the result is smaller
|
||
|
|
export default function invariant(
|
||
|
|
condition: any,
|
||
|
|
// Can provide a string, or a function that returns a string for cases where
|
||
|
|
// the message takes a fair amount of effort to compute
|
||
|
|
message?: string | (() => string)
|
||
|
|
): asserts condition {
|
||
|
|
if (condition) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
// Condition not passed
|
||
|
|
|
||
|
|
// In production we strip the message but still throw
|
||
|
|
if (isDenoDeploy) {
|
||
|
|
throw new Error(prefix);
|
||
|
|
}
|
||
|
|
|
||
|
|
// When not in production we allow the message to pass through
|
||
|
|
// *This block will be removed in production builds*
|
||
|
|
|
||
|
|
const provided: string | undefined =
|
||
|
|
typeof message === "function" ? message() : message;
|
||
|
|
|
||
|
|
// Options:
|
||
|
|
// 1. message provided: `${prefix}: ${provided}`
|
||
|
|
// 2. message not provided: prefix
|
||
|
|
const value: string = provided ? `${prefix}: ${provided}` : prefix;
|
||
|
|
throw new Error(value);
|
||
|
|
}
|