rust/crates/ide_assists/src/handlers/add_turbo_fish.rs
2022-01-02 12:06:14 +02:00

343 lines
7.2 KiB
Rust

use ide_db::defs::{Definition, NameRefClass};
use syntax::{ast, AstNode, SyntaxKind, T};
use crate::{
assist_context::{AssistContext, Assists},
AssistId, AssistKind,
};
// Assist: add_turbo_fish
//
// Adds `::<_>` to a call of a generic method or function.
//
// ```
// fn make<T>() -> T { todo!() }
// fn main() {
// let x = make$0();
// }
// ```
// ->
// ```
// fn make<T>() -> T { todo!() }
// fn main() {
// let x = make::<${0:_}>();
// }
// ```
pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
let ident = ctx.find_token_syntax_at_offset(SyntaxKind::IDENT).or_else(|| {
let arg_list = ctx.find_node_at_offset::<ast::ArgList>()?;
if arg_list.args().next().is_some() {
return None;
}
cov_mark::hit!(add_turbo_fish_after_call);
cov_mark::hit!(add_type_ascription_after_call);
arg_list.l_paren_token()?.prev_token().filter(|it| it.kind() == SyntaxKind::IDENT)
})?;
let next_token = ident.next_token()?;
if next_token.kind() == T![::] {
cov_mark::hit!(add_turbo_fish_one_fish_is_enough);
return None;
}
let name_ref = ast::NameRef::cast(ident.parent()?)?;
let def = match NameRefClass::classify(&ctx.sema, &name_ref)? {
NameRefClass::Definition(def) => def,
NameRefClass::FieldShorthand { .. } => return None,
};
let fun = match def {
Definition::Function(it) => it,
_ => return None,
};
let generics = hir::GenericDef::Function(fun).params(ctx.sema.db);
if generics.is_empty() {
cov_mark::hit!(add_turbo_fish_non_generic);
return None;
}
if let Some(let_stmt) = ctx.find_node_at_offset::<ast::LetStmt>() {
if let_stmt.colon_token().is_none() {
let type_pos = let_stmt.pat()?.syntax().last_token()?.text_range().end();
let semi_pos = let_stmt.syntax().last_token()?.text_range().end();
acc.add(
AssistId("add_type_ascription", AssistKind::RefactorRewrite),
"Add `: _` before assignment operator",
ident.text_range(),
|builder| {
if let_stmt.semicolon_token().is_none() {
builder.insert(semi_pos, ";");
}
match ctx.config.snippet_cap {
Some(cap) => builder.insert_snippet(cap, type_pos, ": ${0:_}"),
None => builder.insert(type_pos, ": _"),
}
},
)?
} else {
cov_mark::hit!(add_type_ascription_already_typed);
}
}
let number_of_arguments = generics.len();
let fish_head = std::iter::repeat("_").take(number_of_arguments).collect::<Vec<_>>().join(",");
acc.add(
AssistId("add_turbo_fish", AssistKind::RefactorRewrite),
"Add `::<>`",
ident.text_range(),
|builder| match ctx.config.snippet_cap {
Some(cap) => {
let snip = format!("::<${{0:{}}}>", fish_head);
builder.insert_snippet(cap, ident.text_range().end(), snip)
}
None => {
let snip = format!("::<{}>", fish_head);
builder.insert(ident.text_range().end(), snip);
}
},
)
}
#[cfg(test)]
mod tests {
use crate::tests::{check_assist, check_assist_by_label, check_assist_not_applicable};
use super::*;
#[test]
fn add_turbo_fish_function() {
check_assist(
add_turbo_fish,
r#"
fn make<T>() -> T {}
fn main() {
make$0();
}
"#,
r#"
fn make<T>() -> T {}
fn main() {
make::<${0:_}>();
}
"#,
);
}
#[test]
fn add_turbo_fish_function_multiple_generic_types() {
check_assist(
add_turbo_fish,
r#"
fn make<T, A>() -> T {}
fn main() {
make$0();
}
"#,
r#"
fn make<T, A>() -> T {}
fn main() {
make::<${0:_,_}>();
}
"#,
);
}
#[test]
fn add_turbo_fish_function_many_generic_types() {
check_assist(
add_turbo_fish,
r#"
fn make<T, A, B, C, D, E, F>() -> T {}
fn main() {
make$0();
}
"#,
r#"
fn make<T, A, B, C, D, E, F>() -> T {}
fn main() {
make::<${0:_,_,_,_,_,_,_}>();
}
"#,
);
}
#[test]
fn add_turbo_fish_after_call() {
cov_mark::check!(add_turbo_fish_after_call);
check_assist(
add_turbo_fish,
r#"
fn make<T>() -> T {}
fn main() {
make()$0;
}
"#,
r#"
fn make<T>() -> T {}
fn main() {
make::<${0:_}>();
}
"#,
);
}
#[test]
fn add_turbo_fish_method() {
check_assist(
add_turbo_fish,
r#"
struct S;
impl S {
fn make<T>(&self) -> T {}
}
fn main() {
S.make$0();
}
"#,
r#"
struct S;
impl S {
fn make<T>(&self) -> T {}
}
fn main() {
S.make::<${0:_}>();
}
"#,
);
}
#[test]
fn add_turbo_fish_one_fish_is_enough() {
cov_mark::check!(add_turbo_fish_one_fish_is_enough);
check_assist_not_applicable(
add_turbo_fish,
r#"
fn make<T>() -> T {}
fn main() {
make$0::<()>();
}
"#,
);
}
#[test]
fn add_turbo_fish_non_generic() {
cov_mark::check!(add_turbo_fish_non_generic);
check_assist_not_applicable(
add_turbo_fish,
r#"
fn make() -> () {}
fn main() {
make$0();
}
"#,
);
}
#[test]
fn add_type_ascription_function() {
check_assist_by_label(
add_turbo_fish,
r#"
fn make<T>() -> T {}
fn main() {
let x = make$0();
}
"#,
r#"
fn make<T>() -> T {}
fn main() {
let x: ${0:_} = make();
}
"#,
"Add `: _` before assignment operator",
);
}
#[test]
fn add_type_ascription_after_call() {
cov_mark::check!(add_type_ascription_after_call);
check_assist_by_label(
add_turbo_fish,
r#"
fn make<T>() -> T {}
fn main() {
let x = make()$0;
}
"#,
r#"
fn make<T>() -> T {}
fn main() {
let x: ${0:_} = make();
}
"#,
"Add `: _` before assignment operator",
);
}
#[test]
fn add_type_ascription_method() {
check_assist_by_label(
add_turbo_fish,
r#"
struct S;
impl S {
fn make<T>(&self) -> T {}
}
fn main() {
let x = S.make$0();
}
"#,
r#"
struct S;
impl S {
fn make<T>(&self) -> T {}
}
fn main() {
let x: ${0:_} = S.make();
}
"#,
"Add `: _` before assignment operator",
);
}
#[test]
fn add_type_ascription_already_typed() {
cov_mark::check!(add_type_ascription_already_typed);
check_assist(
add_turbo_fish,
r#"
fn make<T>() -> T {}
fn main() {
let x: () = make$0();
}
"#,
r#"
fn make<T>() -> T {}
fn main() {
let x: () = make::<${0:_}>();
}
"#,
);
}
#[test]
fn add_type_ascription_append_semicolon() {
check_assist_by_label(
add_turbo_fish,
r#"
fn make<T>() -> T {}
fn main() {
let x = make$0()
}
"#,
r#"
fn make<T>() -> T {}
fn main() {
let x: ${0:_} = make();
}
"#,
"Add `: _` before assignment operator",
);
}
}