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|
use stdx::{format_to, to_lower_snake_case};
use syntax::ast::VisibilityOwner;
use syntax::ast::{self, AstNode, NameOwner};
use test_utils::mark;
use crate::{
utils::{find_impl_block, find_struct_impl},
AssistContext, AssistId, AssistKind, Assists,
};
// Assist: generate_enum_match_method
//
// Generate an `is_` method for an enum variant.
//
// ```
// enum Version {
// Undefined,
// Minor$0,
// Major,
// }
// ```
// ->
// ```
// enum Version {
// Undefined,
// Minor,
// Major,
// }
//
// impl Version {
// /// Returns `true` if the version is [`Minor`].
// fn is_minor(&self) -> bool {
// matches!(self, Self::Minor)
// }
// }
// ```
pub(crate) fn generate_enum_match_method(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
let variant = ctx.find_node_at_offset::<ast::Variant>()?;
let variant_name = variant.name()?;
let parent_enum = variant.parent_enum();
if !matches!(variant.kind(), ast::StructKind::Unit) {
mark::hit!(test_gen_enum_match_on_non_unit_variant_not_implemented);
return None;
}
let enum_lowercase_name = to_lower_snake_case(&parent_enum.name()?.to_string());
let fn_name = to_lower_snake_case(&variant_name.to_string());
// Return early if we've found an existing new fn
let impl_def = find_struct_impl(
&ctx,
&ast::Adt::Enum(parent_enum.clone()),
format!("is_{}", fn_name).as_str(),
)?;
let target = variant.syntax().text_range();
acc.add(
AssistId("generate_enum_match_method", AssistKind::Generate),
"Generate an `is_` method for an enum variant",
target,
|builder| {
let mut buf = String::with_capacity(512);
if impl_def.is_some() {
buf.push('\n');
}
let vis = parent_enum.visibility().map_or(String::new(), |v| format!("{} ", v));
format_to!(
buf,
" /// Returns `true` if the {} is [`{}`].
{}fn is_{}(&self) -> bool {{
matches!(self, Self::{})
}}",
enum_lowercase_name,
variant_name,
vis,
fn_name,
variant_name
);
let start_offset = impl_def
.and_then(|impl_def| find_impl_block(impl_def, &mut buf))
.unwrap_or_else(|| {
buf = generate_impl_text(&parent_enum, &buf);
parent_enum.syntax().text_range().end()
});
builder.insert(start_offset, buf);
},
)
}
// Generates the surrounding `impl Type { <code> }` including type and lifetime
// parameters
fn generate_impl_text(strukt: &ast::Enum, code: &str) -> String {
let mut buf = String::with_capacity(code.len());
buf.push_str("\n\nimpl ");
buf.push_str(strukt.name().unwrap().text());
format_to!(buf, " {{\n{}\n}}", code);
buf
}
#[cfg(test)]
mod tests {
use test_utils::mark;
use crate::tests::{check_assist, check_assist_not_applicable};
use super::*;
fn check_not_applicable(ra_fixture: &str) {
check_assist_not_applicable(generate_enum_match_method, ra_fixture)
}
#[test]
fn test_generate_enum_match_from_variant() {
check_assist(
generate_enum_match_method,
r#"
enum Variant {
Undefined,
Minor$0,
Major,
}"#,
r#"enum Variant {
Undefined,
Minor,
Major,
}
impl Variant {
/// Returns `true` if the variant is [`Minor`].
fn is_minor(&self) -> bool {
matches!(self, Self::Minor)
}
}"#,
);
}
#[test]
fn test_generate_enum_match_already_implemented() {
check_not_applicable(
r#"
enum Variant {
Undefined,
Minor$0,
Major,
}
impl Variant {
fn is_minor(&self) -> bool {
matches!(self, Self::Minor)
}
}"#,
);
}
#[test]
fn test_add_from_impl_no_element() {
mark::check!(test_gen_enum_match_on_non_unit_variant_not_implemented);
check_not_applicable(
r#"
enum Variant {
Undefined,
Minor(u32)$0,
Major,
}"#,
);
}
#[test]
fn test_generate_enum_match_from_variant_with_one_variant() {
check_assist(
generate_enum_match_method,
r#"enum Variant { Undefi$0ned }"#,
r#"
enum Variant { Undefined }
impl Variant {
/// Returns `true` if the variant is [`Undefined`].
fn is_undefined(&self) -> bool {
matches!(self, Self::Undefined)
}
}"#,
);
}
#[test]
fn test_generate_enum_match_from_variant_with_visibility_marker() {
check_assist(
generate_enum_match_method,
r#"
pub(crate) enum Variant {
Undefined,
Minor$0,
Major,
}"#,
r#"pub(crate) enum Variant {
Undefined,
Minor,
Major,
}
impl Variant {
/// Returns `true` if the variant is [`Minor`].
pub(crate) fn is_minor(&self) -> bool {
matches!(self, Self::Minor)
}
}"#,
);
}
}
|
