1 use ide_db::{base_db::FileId, defs::Definition, search::FileReference};
3 algo::find_node_at_range,
4 ast::{self, ArgListOwner},
5 AstNode, SourceFile, SyntaxKind, SyntaxNode, TextRange, T,
8 use SyntaxKind::WHITESPACE;
11 assist_context::AssistBuilder, utils::next_prev, AssistContext, AssistId, AssistKind, Assists,
14 // Assist: remove_unused_param
16 // Removes unused function parameter.
19 // fn frobnicate(x: i32$0) {}
33 pub(crate) fn remove_unused_param(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
34 let param: ast::Param = ctx.find_node_at_offset()?;
35 let ident_pat = match param.pat()? {
36 ast::Pat::IdentPat(it) => it,
39 let func = param.syntax().ancestors().find_map(ast::Fn::cast)?;
41 param.syntax().parent()?.children().find_map(ast::SelfParam::cast).is_some();
43 // check if fn is in impl Trait for ..
46 .parent() // AssocItemList
47 .and_then(|x| x.parent())
48 .and_then(ast::Impl::cast)
49 .map_or(false, |imp| imp.trait_().is_some())
51 cov_mark::hit!(trait_impl);
55 let mut param_position = func.param_list()?.params().position(|it| it == param)?;
56 // param_list() does not take self param into consideration, hence this additional check is
57 // added. There are two cases to handle in this scenario, where functions are
58 // associative(functions not associative and not containting contain self, are not allowed), in
59 // this case param position is rightly set. If a method call is present which has self param,
60 // that needs to be handled and is added below in process_usage function to reduce this increment and
61 // not consider self param.
66 let func = ctx.sema.to_def(&func)?;
67 Definition::ModuleDef(func.into())
71 let local = ctx.sema.to_def(&ident_pat)?;
72 Definition::Local(local)
74 if param_def.usages(&ctx.sema).at_least_one() {
75 cov_mark::hit!(keep_used);
79 AssistId("remove_unused_param", AssistKind::Refactor),
80 "Remove unused parameter",
81 param.syntax().text_range(),
83 builder.delete(range_to_remove(param.syntax()));
84 for (file_id, references) in fn_def.usages(&ctx.sema).all() {
85 process_usages(ctx, builder, file_id, references, param_position, is_self_present);
93 builder: &mut AssistBuilder,
95 references: Vec<FileReference>,
97 is_self_present: bool,
99 let source_file = ctx.sema.parse(file_id);
100 builder.edit_file(file_id);
101 for usage in references {
102 if let Some(text_range) = process_usage(&source_file, usage, arg_to_remove, is_self_present)
104 builder.delete(text_range);
110 source_file: &SourceFile,
111 FileReference { range, .. }: FileReference,
112 mut arg_to_remove: usize,
113 is_self_present: bool,
114 ) -> Option<TextRange> {
115 let call_expr_opt: Option<ast::CallExpr> = find_node_at_range(source_file.syntax(), range);
116 if let Some(call_expr) = call_expr_opt {
117 let call_expr_range = call_expr.expr()?.syntax().text_range();
118 if !call_expr_range.contains_range(range) {
122 let arg = call_expr.arg_list()?.args().nth(arg_to_remove)?;
123 return Some(range_to_remove(arg.syntax()));
126 let method_call_expr_opt: Option<ast::MethodCallExpr> =
127 find_node_at_range(source_file.syntax(), range);
128 if let Some(method_call_expr) = method_call_expr_opt {
129 let method_call_expr_range = method_call_expr.name_ref()?.syntax().text_range();
130 if !method_call_expr_range.contains_range(range) {
138 let arg = method_call_expr.arg_list()?.args().nth(arg_to_remove)?;
139 return Some(range_to_remove(arg.syntax()));
145 fn range_to_remove(node: &SyntaxNode) -> TextRange {
146 let up_to_comma = next_prev().find_map(|dir| {
147 node.siblings_with_tokens(dir)
148 .filter_map(|it| it.into_token())
149 .find(|it| it.kind() == T![,])
152 if let Some((dir, token)) = up_to_comma {
153 if node.next_sibling().is_some() {
154 let up_to_space = token
155 .siblings_with_tokens(dir)
157 .take_while(|it| it.kind() == WHITESPACE)
159 .and_then(|it| it.into_token());
162 .cover(up_to_space.map_or(token.text_range(), |it| it.text_range()));
164 node.text_range().cover(token.text_range())
172 use crate::tests::{check_assist, check_assist_not_applicable};
182 fn foo(x: i32, $0y: i32) { x; }
183 fn b() { foo(9, 2,) }
187 fn foo(x: i32) { x; }
194 fn remove_unused_first_param() {
198 fn foo($0x: i32, y: i32) { y; }
200 fn b() { foo(1, 2,) }
203 fn foo(y: i32) { y; }
211 fn remove_unused_single_param() {
215 fn foo($0x: i32) { 0; }
228 fn remove_unused_surrounded_by_parms() {
232 fn foo(x: i32, $0y: i32, z: i32) { x; }
233 fn a() { foo(1, 2, 3) }
234 fn b() { foo(1, 2, 3,) }
237 fn foo(x: i32, z: i32) { x; }
239 fn b() { foo(1, 3,) }
245 fn remove_unused_qualified_call() {
249 mod bar { pub fn foo(x: i32, $0y: i32) { x; } }
250 fn b() { bar::foo(9, 2) }
253 mod bar { pub fn foo(x: i32) { x; } }
254 fn b() { bar::foo(9) }
260 fn remove_unused_turbofished_func() {
264 pub fn foo<T>(x: T, $0y: i32) { x; }
265 fn b() { foo::<i32>(9, 2) }
268 pub fn foo<T>(x: T) { x; }
269 fn b() { foo::<i32>(9) }
275 fn remove_unused_generic_unused_param_func() {
279 pub fn foo<T>(x: i32, $0y: T) { x; }
280 fn b() { foo::<i32>(9, 2) }
281 fn b2() { foo(9, 2) }
284 pub fn foo<T>(x: i32) { x; }
285 fn b() { foo::<i32>(9) }
293 cov_mark::check!(keep_used);
294 check_assist_not_applicable(
297 fn foo(x: i32, $0y: i32) { y; }
298 fn main() { foo(9, 2) }
305 cov_mark::check!(trait_impl);
306 check_assist_not_applicable(
320 fn remove_across_files() {
325 fn foo(x: i32, $0y: i32) { x; }
338 fn foo(x: i32) { x; }
353 fn test_remove_method_param() {
358 impl S { fn f(&self, $0_unused: i32) {} }
368 impl S { fn f(&self) {} }