nushell/crates/nu-plugin-test-support/tests/lowercase/mod.rs
Devyn Cairns 01d30a416b
Change PluginCommand API to be more like Command (#12279)
# Description

This is something that was discussed in the core team meeting last
Wednesday. @ayax79 is building `nu-plugin-polars` with all of the
dataframe commands into a plugin, and there are a lot of them, so it
would help to make the API more similar. At the same time, I think the
`Command` API is just better anyway. I don't think the difference is
justified, and the types for core commands have the benefit of requiring
less `.into()` because they often don't own their data

- Broke `signature()` up into `name()`, `usage()`, `extra_usage()`,
`search_terms()`, `examples()`
- `signature()` returns `nu_protocol::Signature`
- `examples()` returns `Vec<nu_protocol::Example>`
- `PluginSignature` and `PluginExample` no longer need to be used by
plugin developers

# User-Facing Changes
Breaking API for plugins yet again 😄
2024-03-27 11:59:57 +01:00

86 lines
2.3 KiB
Rust

use nu_plugin::*;
use nu_plugin_test_support::PluginTest;
use nu_protocol::{
Example, IntoInterruptiblePipelineData, LabeledError, PipelineData, ShellError, Signature,
Span, Type, Value,
};
struct LowercasePlugin;
struct Lowercase;
impl PluginCommand for Lowercase {
type Plugin = LowercasePlugin;
fn name(&self) -> &str {
"lowercase"
}
fn usage(&self) -> &str {
"Convert each string in a stream to lowercase"
}
fn signature(&self) -> Signature {
Signature::build(self.name()).input_output_type(
Type::List(Type::String.into()),
Type::List(Type::String.into()),
)
}
fn examples(&self) -> Vec<Example> {
vec![Example {
example: r#"[Hello wORLD] | lowercase"#,
description: "Lowercase a list of strings",
result: Some(Value::test_list(vec![
Value::test_string("hello"),
Value::test_string("world"),
])),
}]
}
fn run(
&self,
_plugin: &LowercasePlugin,
_engine: &EngineInterface,
call: &EvaluatedCall,
input: PipelineData,
) -> Result<PipelineData, LabeledError> {
let span = call.head;
Ok(input.map(
move |value| {
value
.as_str()
.map(|string| Value::string(string.to_lowercase(), span))
// Errors in a stream should be returned as values.
.unwrap_or_else(|err| Value::error(err, span))
},
None,
)?)
}
}
impl Plugin for LowercasePlugin {
fn commands(&self) -> Vec<Box<dyn PluginCommand<Plugin = Self>>> {
vec![Box::new(Lowercase)]
}
}
#[test]
fn test_lowercase_using_eval_with() -> Result<(), ShellError> {
let result = PluginTest::new("lowercase", LowercasePlugin.into())?.eval_with(
"lowercase",
vec![Value::test_string("HeLlO wOrLd")].into_pipeline_data(None),
)?;
assert_eq!(
Value::test_list(vec![Value::test_string("hello world")]),
result.into_value(Span::test_data())
);
Ok(())
}
#[test]
fn test_lowercase_examples() -> Result<(), ShellError> {
PluginTest::new("lowercase", LowercasePlugin.into())?.test_command_examples(&Lowercase)
}