use hir::{db::AstDatabase, diagnostics::ReplaceFilterMapNextWithFindMap, Semantics}; use ide_assists::{Assist, AssistResolveStrategy}; use ide_db::{source_change::SourceChange, RootDatabase}; use syntax::{ ast::{self, ArgListOwner}, AstNode, TextRange, }; use text_edit::TextEdit; use crate::diagnostics::{fix, DiagnosticWithFixes}; impl DiagnosticWithFixes for ReplaceFilterMapNextWithFindMap { fn fixes( &self, sema: &Semantics, _resolve: &AssistResolveStrategy, ) -> Option> { let root = sema.db.parse_or_expand(self.file)?; let next_expr = self.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(self.file.original_file(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::diagnostics::tests::check_fix; #[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| if *x == 2 { Some (4) } else { None }).next(); } //- /core/lib.rs crate:core pub mod option { pub enum Option { Some(T), None } } pub mod iter { pub trait Iterator { type Item; fn filter_map(self, f: F) -> FilterMap where F: FnMut(Self::Item) -> Option { FilterMap } fn next(&mut self) -> Option; } 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| if *x == 2 { Some (4) } else { None }); } "#, ) } }