argsert.js
2.42 KB
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import { YError } from './yerror.js';
import { parseCommand } from './parse-command.js';
const positionName = ['first', 'second', 'third', 'fourth', 'fifth', 'sixth'];
export function argsert(arg1, arg2, arg3) {
function parseArgs() {
return typeof arg1 === 'object'
? [{ demanded: [], optional: [] }, arg1, arg2]
: [
parseCommand(`cmd ${arg1}`),
arg2,
arg3,
];
}
try {
let position = 0;
const [parsed, callerArguments, _length] = parseArgs();
const args = [].slice.call(callerArguments);
while (args.length && args[args.length - 1] === undefined)
args.pop();
const length = _length || args.length;
if (length < parsed.demanded.length) {
throw new YError(`Not enough arguments provided. Expected ${parsed.demanded.length} but received ${args.length}.`);
}
const totalCommands = parsed.demanded.length + parsed.optional.length;
if (length > totalCommands) {
throw new YError(`Too many arguments provided. Expected max ${totalCommands} but received ${length}.`);
}
parsed.demanded.forEach(demanded => {
const arg = args.shift();
const observedType = guessType(arg);
const matchingTypes = demanded.cmd.filter(type => type === observedType || type === '*');
if (matchingTypes.length === 0)
argumentTypeError(observedType, demanded.cmd, position);
position += 1;
});
parsed.optional.forEach(optional => {
if (args.length === 0)
return;
const arg = args.shift();
const observedType = guessType(arg);
const matchingTypes = optional.cmd.filter(type => type === observedType || type === '*');
if (matchingTypes.length === 0)
argumentTypeError(observedType, optional.cmd, position);
position += 1;
});
}
catch (err) {
console.warn(err.stack);
}
}
function guessType(arg) {
if (Array.isArray(arg)) {
return 'array';
}
else if (arg === null) {
return 'null';
}
return typeof arg;
}
function argumentTypeError(observedType, allowedTypes, position) {
throw new YError(`Invalid ${positionName[position] || 'manyith'} argument. Expected ${allowedTypes.join(' or ')} but received ${observedType}.`);
}