rust/crates/ide_assists/src/handlers/generate_getter.rs
2021-06-13 09:24:16 +05:30

377 lines
8.3 KiB
Rust

use stdx::{format_to, to_lower_snake_case};
use syntax::ast::{self, AstNode, NameOwner, VisibilityOwner};
use crate::{
utils::{find_impl_block_end, find_struct_impl, generate_impl_text},
AssistContext, AssistId, AssistKind, Assists, GroupLabel,
};
// Assist: generate_getter
//
// Generate a getter method.
//
// ```
// struct Person {
// nam$0e: String,
// }
// ```
// ->
// ```
// struct Person {
// name: String,
// }
//
// impl Person {
// /// Get a reference to the person's name.
// fn $0name(&self) -> &str {
// self.name.as_str()
// }
// }
// ```
pub(crate) fn generate_getter(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
generate_getter_impl(acc, ctx, false)
}
// Assist: generate_getter_mut
//
// Generate a mut getter method.
//
// ```
// struct Person {
// nam$0e: String,
// }
// ```
// ->
// ```
// struct Person {
// name: String,
// }
//
// impl Person {
// /// Get a mutable reference to the person's name.
// fn $0name_mut(&mut self) -> &mut String {
// &mut self.name
// }
// }
// ```
pub(crate) fn generate_getter_mut(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
generate_getter_impl(acc, ctx, true)
}
pub(crate) fn generate_getter_impl(
acc: &mut Assists,
ctx: &AssistContext,
mutable: bool,
) -> Option<()> {
let strukt = ctx.find_node_at_offset::<ast::Struct>()?;
let field = ctx.find_node_at_offset::<ast::RecordField>()?;
let strukt_name = strukt.name()?;
let field_name = field.name()?;
let field_ty = field.ty()?;
// Return early if we've found an existing fn
let mut fn_name = to_lower_snake_case(&field_name.to_string());
if mutable {
format_to!(fn_name, "_mut");
}
let impl_def = find_struct_impl(ctx, &ast::Adt::Struct(strukt.clone()), fn_name.as_str())?;
let (id, label) = if mutable {
("generate_getter_mut", "Generate a mut getter method")
} else {
("generate_getter", "Generate a getter method")
};
let target = field.syntax().text_range();
acc.add_group(
&GroupLabel("Generate getter/setter".to_owned()),
AssistId(id, AssistKind::Generate),
label,
target,
|builder| {
let mut buf = String::with_capacity(512);
if impl_def.is_some() {
buf.push('\n');
}
let vis = strukt.visibility().map_or(String::new(), |v| format!("{} ", v));
let (ty, body) = if mutable {
(format!("&mut {}", field_ty), format!("&mut self.{}", field_name))
} else {
useless_type_special_case(&field_name.to_string(), &field_ty)
.unwrap_or_else(|| (format!("&{}", field_ty), format!("&self.{}", field_name)))
};
format_to!(
buf,
" /// Get a {}reference to the {}'s {}.
{}fn {}(&{}self) -> {} {{
{}
}}",
mutable.then(|| "mutable ").unwrap_or_default(),
to_lower_snake_case(&strukt_name.to_string()).replace('_', " "),
fn_name.trim_end_matches("_mut").replace('_', " "),
vis,
fn_name,
mutable.then(|| "mut ").unwrap_or_default(),
ty,
body,
);
let start_offset = impl_def
.and_then(|impl_def| find_impl_block_end(impl_def, &mut buf))
.unwrap_or_else(|| {
buf = generate_impl_text(&ast::Adt::Struct(strukt.clone()), &buf);
strukt.syntax().text_range().end()
});
match ctx.config.snippet_cap {
Some(cap) => {
builder.insert_snippet(cap, start_offset, buf.replacen("fn ", "fn $0", 1))
}
None => builder.insert(start_offset, buf),
}
},
)
}
fn useless_type_special_case(field_name: &str, field_ty: &ast::Type) -> Option<(String, String)> {
if field_ty.to_string() == "String" {
cov_mark::hit!(useless_type_special_case);
return Some(("&str".to_string(), format!("self.{}.as_str()", field_name)));
}
if let Some(arg) = ty_ctor(field_ty, "Vec") {
return Some((format!("&[{}]", arg), format!("self.{}.as_slice()", field_name)));
}
if let Some(arg) = ty_ctor(field_ty, "Box") {
return Some((format!("&{}", arg), format!("self.{}.as_ref()", field_name)));
}
if let Some(arg) = ty_ctor(field_ty, "Option") {
return Some((format!("Option<&{}>", arg), format!("self.{}.as_ref()", field_name)));
}
None
}
// FIXME: This should rely on semantic info.
fn ty_ctor(ty: &ast::Type, ctor: &str) -> Option<String> {
let res = ty.to_string().strip_prefix(ctor)?.strip_prefix('<')?.strip_suffix('>')?.to_string();
Some(res)
}
#[cfg(test)]
mod tests {
use crate::tests::{check_assist, check_assist_not_applicable};
use super::*;
#[test]
fn test_generate_getter_from_field() {
check_assist(
generate_getter,
r#"
struct Context {
dat$0a: Data,
}
"#,
r#"
struct Context {
data: Data,
}
impl Context {
/// Get a reference to the context's data.
fn $0data(&self) -> &Data {
&self.data
}
}
"#,
);
check_assist(
generate_getter_mut,
r#"
struct Context {
dat$0a: Data,
}
"#,
r#"
struct Context {
data: Data,
}
impl Context {
/// Get a mutable reference to the context's data.
fn $0data_mut(&mut self) -> &mut Data {
&mut self.data
}
}
"#,
);
}
#[test]
fn test_generate_getter_already_implemented() {
check_assist_not_applicable(
generate_getter,
r#"
struct Context {
dat$0a: Data,
}
impl Context {
fn data(&self) -> &Data {
&self.data
}
}
"#,
);
check_assist_not_applicable(
generate_getter_mut,
r#"
struct Context {
dat$0a: Data,
}
impl Context {
fn data_mut(&mut self) -> &mut Data {
&mut self.data
}
}
"#,
);
}
#[test]
fn test_generate_getter_from_field_with_visibility_marker() {
check_assist(
generate_getter,
r#"
pub(crate) struct Context {
dat$0a: Data,
}
"#,
r#"
pub(crate) struct Context {
data: Data,
}
impl Context {
/// Get a reference to the context's data.
pub(crate) fn $0data(&self) -> &Data {
&self.data
}
}
"#,
);
}
#[test]
fn test_multiple_generate_getter() {
check_assist(
generate_getter,
r#"
struct Context {
data: Data,
cou$0nt: usize,
}
impl Context {
/// Get a reference to the context's data.
fn data(&self) -> &Data {
&self.data
}
}
"#,
r#"
struct Context {
data: Data,
count: usize,
}
impl Context {
/// Get a reference to the context's data.
fn data(&self) -> &Data {
&self.data
}
/// Get a reference to the context's count.
fn $0count(&self) -> &usize {
&self.count
}
}
"#,
);
}
#[test]
fn test_special_cases() {
cov_mark::check!(useless_type_special_case);
check_assist(
generate_getter,
r#"
struct S { foo: $0String }
"#,
r#"
struct S { foo: String }
impl S {
/// Get a reference to the s's foo.
fn $0foo(&self) -> &str {
self.foo.as_str()
}
}
"#,
);
check_assist(
generate_getter,
r#"
struct S { foo: $0Box<Sweets> }
"#,
r#"
struct S { foo: Box<Sweets> }
impl S {
/// Get a reference to the s's foo.
fn $0foo(&self) -> &Sweets {
self.foo.as_ref()
}
}
"#,
);
check_assist(
generate_getter,
r#"
struct S { foo: $0Vec<()> }
"#,
r#"
struct S { foo: Vec<()> }
impl S {
/// Get a reference to the s's foo.
fn $0foo(&self) -> &[()] {
self.foo.as_slice()
}
}
"#,
);
check_assist(
generate_getter,
r#"
struct S { foo: $0Option<Failure> }
"#,
r#"
struct S { foo: Option<Failure> }
impl S {
/// Get a reference to the s's foo.
fn $0foo(&self) -> Option<&Failure> {
self.foo.as_ref()
}
}
"#,
);
}
}