use crate::prelude::*; use nu_engine::WholeStreamCommand; use nu_errors::ShellError; use nu_protocol::ShellTypeName; use nu_protocol::{ ColumnPath, Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value, }; use nu_source::Tag; use nu_value_ext::ValueExt; struct Arguments { column_paths: Vec, } pub struct SubCommand; impl WholeStreamCommand for SubCommand { fn name(&self) -> &str { "str capitalize" } fn signature(&self) -> Signature { Signature::build("str capitalize").rest( SyntaxShape::ColumnPath, "optionally capitalize text by column paths", ) } fn usage(&self) -> &str { "capitalizes text" } fn run_with_actions(&self, args: CommandArgs) -> Result { operate(args) } fn examples(&self) -> Vec { vec![Example { description: "Capitalize contents", example: "echo 'good day' | str capitalize", result: Some(vec![Value::from("Good day")]), }] } } fn operate(args: CommandArgs) -> Result { let (options, input) = ( Arguments { column_paths: args.rest(0)?, }, args.input, ); Ok(input .map(move |v| { if options.column_paths.is_empty() { ReturnSuccess::value(action(&v, v.tag())?) } else { let mut ret = v; for path in &options.column_paths { ret = ret.swap_data_by_column_path( path, Box::new(move |old| action(old, old.tag())), )?; } ReturnSuccess::value(ret) } }) .into_action_stream()) } fn action(input: &Value, tag: impl Into) -> Result { match &input.value { UntaggedValue::Primitive(Primitive::String(s)) => { let mut capitalized = String::new(); for (idx, character) in s.chars().enumerate() { let out = if idx == 0 { character.to_uppercase().to_string() } else { character.to_lowercase().to_string() }; capitalized.push_str(&out); } Ok(UntaggedValue::string(capitalized).into_value(tag)) } other => { let got = format!("got {}", other.type_name()); Err(ShellError::labeled_error( "value is not string", got, tag.into().span, )) } } } #[cfg(test)] mod tests { use super::ShellError; use super::{action, SubCommand}; use nu_source::Tag; use nu_test_support::value::string; #[test] fn examples_work_as_expected() -> Result<(), ShellError> { use crate::examples::test as test_examples; test_examples(SubCommand {}) } #[test] fn capitalizes() { let word = string("andres"); let expected = string("Andres"); let actual = action(&word, Tag::unknown()).unwrap(); assert_eq!(actual, expected); } }