diff --git a/crates/ide_assists/src/handlers/generate_default_from_new.rs b/crates/ide_assists/src/handlers/generate_default_from_new.rs new file mode 100644 index 00000000000..fa12545792f --- /dev/null +++ b/crates/ide_assists/src/handlers/generate_default_from_new.rs @@ -0,0 +1,374 @@ +use crate::{ + assist_context::{AssistContext, Assists}, + AssistId, +}; +use ide_db::helpers::FamousDefs; +use syntax::{ + ast::{self, Impl, NameOwner}, + AstNode, +}; +use test_utils::mark; + +// Assist: generate_default_from_new +// +// Generates default implementation from new method. +// +// ``` +// struct Example { _inner: () } +// +// impl Example { +// pub fn n$0ew() -> Self { +// Self { _inner: () } +// } +// } +// ``` +// -> +// ``` +// struct Example { _inner: () } +// +// impl Example { +// pub fn new() -> Self { +// Self { _inner: () } +// } +// } +// +// impl Default for Example { +// fn default() -> Self { +// Self::new() +// } +// } +// ``` +pub(crate) fn generate_default_from_new(acc: &mut Assists, ctx: &AssistContext) -> Option<()> { + let fn_node = ctx.find_node_at_offset::()?; + let fn_name = fn_node.name()?; + + if fn_name.text() != "new" { + mark::hit!(other_function_than_new); + return None; + } + + if fn_node.param_list()?.params().next().is_some() { + mark::hit!(new_function_with_parameters); + return None; + } + + let impl_ = fn_node.syntax().ancestors().into_iter().find_map(ast::Impl::cast)?; + if is_default_implemented(ctx, &impl_) { + mark::hit!(default_block_is_already_present); + mark::hit!(struct_in_module_with_default); + return None; + } + + let insert_location = impl_.syntax().text_range(); + + acc.add( + AssistId("generate_default_from_new", crate::AssistKind::Generate), + "Generate a Default impl from a new fn", + insert_location, + move |builder| { + let code = default_fn_node_for_new(impl_); + builder.insert(insert_location.end(), code); + }, + ) +} + +fn default_fn_node_for_new(impl_: Impl) -> String { + format!( + " + +impl Default for {} {{ + fn default() -> Self {{ + Self::new() + }} +}}", + impl_.self_ty().unwrap().syntax().text() + ) +} + +fn is_default_implemented(ctx: &AssistContext, impl_: &Impl) -> bool { + let db = ctx.sema.db; + let impl_ = ctx.sema.to_def(impl_); + let impl_def = match impl_ { + Some(value) => value, + None => return false, + }; + + let ty = impl_def.target_ty(db); + let krate = impl_def.module(db).krate(); + let default = FamousDefs(&ctx.sema, Some(krate)).core_default_Default(); + let default_trait = match default { + Some(value) => value, + None => return false, + }; + + ty.impls_trait(db, default_trait, &[]) +} + +#[cfg(test)] +mod tests { + use ide_db::helpers::FamousDefs; + + use crate::tests::{check_assist, check_assist_not_applicable}; + + use super::*; + + #[test] + fn generate_default() { + check_pass( + r#" +struct Example { _inner: () } + +impl Example { + pub fn ne$0w() -> Self { + Self { _inner: () } + } +} + +fn main() {} +"#, + r#" +struct Example { _inner: () } + +impl Example { + pub fn new() -> Self { + Self { _inner: () } + } +} + +impl Default for Example { + fn default() -> Self { + Self::new() + } +} + +fn main() {} +"#, + ); + } + + #[test] + fn generate_default2() { + check_pass( + r#" +struct Test { value: u32 } + +impl Test { + pub fn ne$0w() -> Self { + Self { value: 0 } + } +} +"#, + r#" +struct Test { value: u32 } + +impl Test { + pub fn new() -> Self { + Self { value: 0 } + } +} + +impl Default for Test { + fn default() -> Self { + Self::new() + } +} +"#, + ); + } + + #[test] + fn new_function_with_parameters() { + mark::check!(new_function_with_parameters); + check_not_applicable( + r#" +struct Example { _inner: () } + +impl Example { + pub fn $0new(value: ()) -> Self { + Self { _inner: value } + } +} +"#, + ); + } + + #[test] + fn other_function_than_new() { + mark::check!(other_function_than_new); + check_not_applicable( + r#" +struct Example { _inner: () } + +impl Example { + pub fn a$0dd() -> Self { + Self { _inner: () } + } +} + +"#, + ); + } + + #[test] + fn default_block_is_already_present() { + mark::check!(default_block_is_already_present); + check_not_applicable( + r#" +struct Example { _inner: () } + +impl Example { + pub fn n$0ew() -> Self { + Self { _inner: () } + } +} + +impl Default for Example { + fn default() -> Self { + Self::new() + } +} +"#, + ); + } + + #[test] + fn standalone_new_function() { + check_not_applicable( + r#" +fn n$0ew() -> u32 { + 0 +} +"#, + ); + } + + #[test] + fn multiple_struct_blocks() { + check_pass( + r#" +struct Example { _inner: () } +struct Test { value: u32 } + +impl Example { + pub fn new$0() -> Self { + Self { _inner: () } + } +} +"#, + r#" +struct Example { _inner: () } +struct Test { value: u32 } + +impl Example { + pub fn new() -> Self { + Self { _inner: () } + } +} + +impl Default for Example { + fn default() -> Self { + Self::new() + } +} +"#, + ); + } + + #[test] + fn when_struct_is_after_impl() { + check_pass( + r#" +impl Example { + pub fn $0new() -> Self { + Self { _inner: () } + } +} + +struct Example { _inner: () } +"#, + r#" +impl Example { + pub fn new() -> Self { + Self { _inner: () } + } +} + +impl Default for Example { + fn default() -> Self { + Self::new() + } +} + +struct Example { _inner: () } +"#, + ); + } + + #[test] + fn struct_in_module() { + check_pass( + r#" +mod test { + struct Example { _inner: () } + + impl Example { + pub fn n$0ew() -> Self { + Self { _inner: () } + } + } +} +"#, + r#" +mod test { + struct Example { _inner: () } + + impl Example { + pub fn new() -> Self { + Self { _inner: () } + } + } + +impl Default for Example { + fn default() -> Self { + Self::new() + } +} +} +"#, + ); + } + + #[test] + fn struct_in_module_with_default() { + mark::check!(struct_in_module_with_default); + check_not_applicable( + r#" +mod test { + struct Example { _inner: () } + + impl Example { + pub fn n$0ew() -> Self { + Self { _inner: () } + } + } + + impl Default for Example { + fn default() -> Self { + Self::new() + } + } +} +"#, + ); + } + + fn check_pass(before: &str, after: &str) { + let before = &format!("//- /main.rs crate:main deps:core{}{}", before, FamousDefs::FIXTURE); + check_assist(generate_default_from_new, before, after); + } + + fn check_not_applicable(before: &str) { + let before = &format!("//- /main.rs crate:main deps:core{}{}", before, FamousDefs::FIXTURE); + check_assist_not_applicable(generate_default_from_new, before); + } +} diff --git a/crates/ide_assists/src/lib.rs b/crates/ide_assists/src/lib.rs index 9c8148462c0..ea62d5f5da1 100644 --- a/crates/ide_assists/src/lib.rs +++ b/crates/ide_assists/src/lib.rs @@ -127,6 +127,7 @@ mod handlers { mod flip_comma; mod flip_trait_bound; mod generate_default_from_enum_variant; + mod generate_default_from_new; mod generate_derive; mod generate_enum_is_method; mod generate_enum_projection_method; @@ -189,6 +190,7 @@ mod handlers { flip_comma::flip_comma, flip_trait_bound::flip_trait_bound, generate_default_from_enum_variant::generate_default_from_enum_variant, + generate_default_from_new::generate_default_from_new, generate_derive::generate_derive, generate_enum_is_method::generate_enum_is_method, generate_enum_projection_method::generate_enum_as_method, diff --git a/crates/ide_assists/src/tests/generated.rs b/crates/ide_assists/src/tests/generated.rs index 4f007aa48bb..304b5798f29 100644 --- a/crates/ide_assists/src/tests/generated.rs +++ b/crates/ide_assists/src/tests/generated.rs @@ -439,6 +439,37 @@ impl Default for Version { ) } +#[test] +fn doctest_generate_default_from_new() { + check_doc_test( + "generate_default_from_new", + r#####" +struct Example { _inner: () } + +impl Example { + pub fn n$0ew() -> Self { + Self { _inner: () } + } +} +"#####, + r#####" +struct Example { _inner: () } + +impl Example { + pub fn new() -> Self { + Self { _inner: () } + } +} + +impl Default for Example { + fn default() -> Self { + Self::new() + } +} +"#####, + ) +} + #[test] fn doctest_generate_derive() { check_doc_test(