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|
use hir::{db::AstDatabase, InFile};
use ide_db::source_change::SourceChange;
use syntax::{
ast::{self, ArgListOwner},
AstNode, TextRange,
};
use text_edit::TextEdit;
use crate::{fix, Assist, Diagnostic, DiagnosticsContext, Severity};
// Diagnostic: replace-filter-map-next-with-find-map
//
// This diagnostic is triggered when `.filter_map(..).next()` is used, rather than the more concise `.find_map(..)`.
pub(crate) fn replace_filter_map_next_with_find_map(
ctx: &DiagnosticsContext<'_>,
d: &hir::ReplaceFilterMapNextWithFindMap,
) -> Diagnostic {
Diagnostic::new(
"replace-filter-map-next-with-find-map",
"replace filter_map(..).next() with find_map(..)",
ctx.sema.diagnostics_display_range(InFile::new(d.file, d.next_expr.clone().into())).range,
)
.severity(Severity::WeakWarning)
.with_fixes(fixes(ctx, d))
}
fn fixes(
ctx: &DiagnosticsContext<'_>,
d: &hir::ReplaceFilterMapNextWithFindMap,
) -> Option<Vec<Assist>> {
let root = ctx.sema.db.parse_or_expand(d.file)?;
let next_expr = d.next_expr.to_node(&root);
let next_call = ast::MethodCallExpr::cast(next_expr.syntax().clone())?;
let filter_map_call = ast::MethodCallExpr::cast(next_call.receiver()?.syntax().clone())?;
let filter_map_name_range = filter_map_call.name_ref()?.ident_token()?.text_range();
let filter_map_args = filter_map_call.arg_list()?;
let range_to_replace =
TextRange::new(filter_map_name_range.start(), next_expr.syntax().text_range().end());
let replacement = format!("find_map{}", filter_map_args.syntax().text());
let trigger_range = next_expr.syntax().text_range();
let edit = TextEdit::replace(range_to_replace, replacement);
let source_change = SourceChange::from_text_edit(d.file.original_file(ctx.sema.db), edit);
Some(vec![fix(
"replace_with_find_map",
"Replace filter_map(..).next() with find_map()",
source_change,
trigger_range,
)])
}
#[cfg(test)]
mod tests {
use crate::tests::check_fix;
// Register the required standard library types to make the tests work
#[track_caller]
fn check_diagnostics(ra_fixture: &str) {
let prefix = r#"
//- /main.rs crate:main deps:core
use core::iter::Iterator;
use core::option::Option::{self, Some, None};
"#;
let suffix = r#"
//- /core/lib.rs crate:core
pub mod option {
pub enum Option<T> { Some(T), None }
}
pub mod iter {
pub trait Iterator {
type Item;
fn filter_map<B, F>(self, f: F) -> FilterMap where F: FnMut(Self::Item) -> Option<B> { FilterMap }
fn next(&mut self) -> Option<Self::Item>;
}
pub struct FilterMap {}
impl Iterator for FilterMap {
type Item = i32;
fn next(&mut self) -> i32 { 7 }
}
}
"#;
crate::tests::check_diagnostics(&format!("{}{}{}", prefix, ra_fixture, suffix))
}
#[test]
fn replace_filter_map_next_with_find_map2() {
check_diagnostics(
r#"
fn foo() {
let m = [1, 2, 3].iter().filter_map(|x| Some(92)).next();
} //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 💡 weak: replace filter_map(..).next() with find_map(..)
"#,
);
}
#[test]
fn replace_filter_map_next_with_find_map_no_diagnostic_without_next() {
check_diagnostics(
r#"
fn foo() {
let m = [1, 2, 3]
.iter()
.filter_map(|x| Some(92))
.len();
}
"#,
);
}
#[test]
fn replace_filter_map_next_with_find_map_no_diagnostic_with_intervening_methods() {
check_diagnostics(
r#"
fn foo() {
let m = [1, 2, 3]
.iter()
.filter_map(|x| Some(92))
.map(|x| x + 2)
.len();
}
"#,
);
}
#[test]
fn replace_filter_map_next_with_find_map_no_diagnostic_if_not_in_chain() {
check_diagnostics(
r#"
fn foo() {
let m = [1, 2, 3]
.iter()
.filter_map(|x| Some(92));
let n = m.next();
}
"#,
);
}
#[test]
fn replace_with_wind_map() {
check_fix(
r#"
//- /main.rs crate:main deps:core
use core::iter::Iterator;
use core::option::Option::{self, Some, None};
fn foo() {
let m = [1, 2, 3].iter().$0filter_map(|x| Some(92)).next();
}
//- /core/lib.rs crate:core
pub mod option {
pub enum Option<T> { Some(T), None }
}
pub mod iter {
pub trait Iterator {
type Item;
fn filter_map<B, F>(self, f: F) -> FilterMap where F: FnMut(Self::Item) -> Option<B> { FilterMap }
fn next(&mut self) -> Option<Self::Item>;
}
pub struct FilterMap {}
impl Iterator for FilterMap {
type Item = i32;
fn next(&mut self) -> i32 { 7 }
}
}
"#,
r#"
use core::iter::Iterator;
use core::option::Option::{self, Some, None};
fn foo() {
let m = [1, 2, 3].iter().find_map(|x| Some(92));
}
"#,
)
}
}
|
