nushell/crates/nu-cli/src/commands/random/bool.rs

99 lines
2.4 KiB
Rust

use crate::commands::WholeStreamCommand;
use crate::prelude::*;
use nu_errors::ShellError;
use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue};
use nu_source::Tagged;
use rand::prelude::{thread_rng, Rng};
pub struct SubCommand;
#[derive(Deserialize)]
pub struct BoolArgs {
bias: Option<Tagged<f64>>,
}
#[async_trait]
impl WholeStreamCommand for SubCommand {
fn name(&self) -> &str {
"random bool"
}
fn signature(&self) -> Signature {
Signature::build("random bool").named(
"bias",
SyntaxShape::Number,
"Adjusts the probability of a \"true\" outcome",
Some('b'),
)
}
fn usage(&self) -> &str {
"Generate a random boolean value"
}
async fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
bool_command(args, registry).await
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Generate a random boolean value",
example: "random bool",
result: None,
},
Example {
description: "Generate a random boolean value with a 75% chance of \"true\"",
example: "random bool --bias 0.75",
result: None,
},
]
}
}
pub async fn bool_command(
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
let (BoolArgs { bias }, _) = args.process(&registry).await?;
let mut probability = 0.5;
if let Some(prob) = bias {
probability = *prob as f64;
let probability_is_valid = 0.0 <= probability && probability <= 1.0;
if !probability_is_valid {
return Err(ShellError::labeled_error(
"The probability is invalid",
"invalid probability",
prob.span(),
));
}
}
let mut rng = thread_rng();
let bool_result: bool = rng.gen_bool(probability);
let bool_untagged_value = UntaggedValue::boolean(bool_result);
Ok(OutputStream::one(ReturnSuccess::value(bool_untagged_value)))
}
#[cfg(test)]
mod tests {
use super::ShellError;
use super::SubCommand;
#[test]
fn examples_work_as_expected() -> Result<(), ShellError> {
use crate::examples::test as test_examples;
Ok(test_examples(SubCommand {})?)
}
}