Boolean arguments read via environment variables do not support no-prefixed variants #2501
Description
Given the following script:
#!/usr/bin/env node
import yargs from 'yargs';
import { hideBin } from 'yargs/helpers';
const argv = yargs(
hideBin(process.argv)
).env(
"MY_CMD"
).option(
'doThing',
{type: 'boolean', default: true}
).parse()
console.log(`DO THING? ${argv.doThing}`);My expectation would be that MY_CMD_DO_THING's environment variable would map to booleans in "the right way". I'd also expect for MY_CMD_NO_DO_THING to map to --no-do-thing's behavior.
Instead I've experienced the following:
+ bun run ./main.js
DO THING? true // expected: default is true
+ MY_CMD_DO_THING=1
+ bun run ./main.js
DO THING? false // unexpected: expected true by "1" being "truth"-y
+ MY_CMD_DO_THING=0
+ bun run ./main.js
DO THING? false // expected: expected false by "0" being "false"-y
+ MY_CMD_DO_THING=true
+ bun run ./main.js
DO THING? true // seems fine
+ MY_CMD_DO_THING=false
+ bun run ./main.js
DO THING? false // seems fine
+ MY_CMD_NO_DO_THING=1
+ bun run ./main.js
DO THING? true // unexpected: expected false by no-do-thing + 1 being "truth"-y
+ MY_CMD_NO_DO_THING=0
+ bun run ./main.js
DO THING? true // guess this is right
+ MY_CMD_NO_DO_THING=true
+ bun run ./main.js
DO THING? true. // unexpected: expected false by no-do-thing + true being truthy
+ MY_CMD_NO_DO_THING=false
+ bun run ./main.js
DO THING? true
I think NO_DO_THING is just not looked at in its entirety, which isn't the end of the world, but seems to lack some notion of parity with the rest of the negation behavior.
But for CLI applications, having 1 or 0 represent true or false feels like something that makes sense. Here 1 turning into a false-y result is very surprising to me.