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|
use ra_syntax::{
ast::{self, AstNode},
Direction, SmolStr,
SyntaxKind::{IDENT, WHITESPACE},
TextRange, TextSize,
};
use stdx::SepBy;
use crate::{Assist, AssistCtx, AssistId};
// Assist: add_custom_impl
//
// Adds impl block for derived trait.
//
// ```
// #[derive(Deb<|>ug, Display)]
// struct S;
// ```
// ->
// ```
// #[derive(Display)]
// struct S;
//
// impl Debug for S {
//
// }
// ```
pub(crate) fn add_custom_impl(ctx: AssistCtx) -> Option<Assist> {
let input = ctx.find_node_at_offset::<ast::AttrInput>()?;
let attr = input.syntax().parent().and_then(ast::Attr::cast)?;
let attr_name = attr
.syntax()
.descendants_with_tokens()
.filter(|t| t.kind() == IDENT)
.find_map(|i| i.into_token())
.filter(|t| *t.text() == "derive")?
.text()
.clone();
let trait_token =
ctx.token_at_offset().find(|t| t.kind() == IDENT && *t.text() != attr_name)?;
let annotated = attr.syntax().siblings(Direction::Next).find_map(ast::Name::cast)?;
let annotated_name = annotated.syntax().text().to_string();
let start_offset = annotated.syntax().parent()?.text_range().end();
let label =
format!("Add custom impl '{}' for '{}'", trait_token.text().as_str(), annotated_name);
ctx.add_assist(AssistId("add_custom_impl"), label, |edit| {
edit.target(attr.syntax().text_range());
let new_attr_input = input
.syntax()
.descendants_with_tokens()
.filter(|t| t.kind() == IDENT)
.filter_map(|t| t.into_token().map(|t| t.text().clone()))
.filter(|t| t != trait_token.text())
.collect::<Vec<SmolStr>>();
let has_more_derives = !new_attr_input.is_empty();
let new_attr_input = new_attr_input.iter().sep_by(", ").surround_with("(", ")").to_string();
let new_attr_input_len = new_attr_input.len();
let mut buf = String::new();
buf.push_str("\n\nimpl ");
buf.push_str(trait_token.text().as_str());
buf.push_str(" for ");
buf.push_str(annotated_name.as_str());
buf.push_str(" {\n");
let cursor_delta = if has_more_derives {
edit.replace(input.syntax().text_range(), new_attr_input);
input.syntax().text_range().len() - TextSize::from_usize(new_attr_input_len)
} else {
let attr_range = attr.syntax().text_range();
edit.delete(attr_range);
let line_break_range = attr
.syntax()
.next_sibling_or_token()
.filter(|t| t.kind() == WHITESPACE)
.map(|t| t.text_range())
.unwrap_or_else(|| TextRange::new(TextSize::from(0), TextSize::from(0)));
edit.delete(line_break_range);
attr_range.len() + line_break_range.len()
};
edit.set_cursor(start_offset + TextSize::of(&buf) - cursor_delta);
buf.push_str("\n}");
edit.insert(start_offset, buf);
})
}
#[cfg(test)]
mod tests {
use crate::helpers::{check_assist, check_assist_not_applicable};
use super::*;
#[test]
fn add_custom_impl_for_unique_input() {
check_assist(
add_custom_impl,
"
#[derive(Debu<|>g)]
struct Foo {
bar: String,
}
",
"
struct Foo {
bar: String,
}
impl Debug for Foo {
<|>
}
",
)
}
#[test]
fn add_custom_impl_for_with_visibility_modifier() {
check_assist(
add_custom_impl,
"
#[derive(Debug<|>)]
pub struct Foo {
bar: String,
}
",
"
pub struct Foo {
bar: String,
}
impl Debug for Foo {
<|>
}
",
)
}
#[test]
fn add_custom_impl_when_multiple_inputs() {
check_assist(
add_custom_impl,
"
#[derive(Display, Debug<|>, Serialize)]
struct Foo {}
",
"
#[derive(Display, Serialize)]
struct Foo {}
impl Debug for Foo {
<|>
}
",
)
}
#[test]
fn test_ignore_derive_macro_without_input() {
check_assist_not_applicable(
add_custom_impl,
"
#[derive(<|>)]
struct Foo {}
",
)
}
#[test]
fn test_ignore_if_cursor_on_param() {
check_assist_not_applicable(
add_custom_impl,
"
#[derive<|>(Debug)]
struct Foo {}
",
);
check_assist_not_applicable(
add_custom_impl,
"
#[derive(Debug)<|>]
struct Foo {}
",
)
}
#[test]
fn test_ignore_if_not_derive() {
check_assist_not_applicable(
add_custom_impl,
"
#[allow(non_camel_<|>case_types)]
struct Foo {}
",
)
}
}
|
