use hir::db::HirDatabase; use ra_syntax::{ ast::{self, AstNode, AstToken}, TextRange, }; use crate::assist_ctx::ActionBuilder; use crate::{Assist, AssistCtx, AssistId}; // Assist: inline_local_variable // // Inlines local variable. // // ``` // fn main() { // let x<|> = 1 + 2; // x * 4; // } // ``` // -> // ``` // fn main() { // (1 + 2) * 4; // } // ``` pub(crate) fn inline_local_variable(ctx: AssistCtx) -> Option { let let_stmt = ctx.find_node_at_offset::()?; let bind_pat = match let_stmt.pat()? { ast::Pat::BindPat(pat) => pat, _ => return None, }; if bind_pat.is_mutable() { return None; } let initializer_expr = let_stmt.initializer()?; let delete_range = if let Some(whitespace) = let_stmt .syntax() .next_sibling_or_token() .and_then(|it| ast::Whitespace::cast(it.as_token()?.clone())) { TextRange::from_to( let_stmt.syntax().text_range().start(), whitespace.syntax().text_range().end(), ) } else { let_stmt.syntax().text_range() }; let analyzer = ctx.source_analyzer(bind_pat.syntax(), None); let refs = analyzer.find_all_refs(&bind_pat); let mut wrap_in_parens = vec![true; refs.len()]; for (i, desc) in refs.iter().enumerate() { let usage_node = ctx.covering_node_for_range(desc.range).ancestors().find_map(ast::PathExpr::cast)?; let usage_parent_option = usage_node.syntax().parent().and_then(ast::Expr::cast); let usage_parent = match usage_parent_option { Some(u) => u, None => { wrap_in_parens[i] = false; continue; } }; wrap_in_parens[i] = match (&initializer_expr, usage_parent) { (ast::Expr::CallExpr(_), _) | (ast::Expr::IndexExpr(_), _) | (ast::Expr::MethodCallExpr(_), _) | (ast::Expr::FieldExpr(_), _) | (ast::Expr::TryExpr(_), _) | (ast::Expr::RefExpr(_), _) | (ast::Expr::Literal(_), _) | (ast::Expr::TupleExpr(_), _) | (ast::Expr::ArrayExpr(_), _) | (ast::Expr::ParenExpr(_), _) | (ast::Expr::PathExpr(_), _) | (ast::Expr::BlockExpr(_), _) | (_, ast::Expr::CallExpr(_)) | (_, ast::Expr::TupleExpr(_)) | (_, ast::Expr::ArrayExpr(_)) | (_, ast::Expr::ParenExpr(_)) | (_, ast::Expr::ForExpr(_)) | (_, ast::Expr::WhileExpr(_)) | (_, ast::Expr::BreakExpr(_)) | (_, ast::Expr::ReturnExpr(_)) | (_, ast::Expr::MatchExpr(_)) => false, _ => true, }; } let init_str = initializer_expr.syntax().text().to_string(); let init_in_paren = format!("({})", &init_str); ctx.add_assist( AssistId("inline_local_variable"), "Inline variable", move |edit: &mut ActionBuilder| { edit.delete(delete_range); for (desc, should_wrap) in refs.iter().zip(wrap_in_parens) { if should_wrap { edit.replace(desc.range, init_in_paren.clone()) } else { edit.replace(desc.range, init_str.clone()) } } edit.set_cursor(delete_range.start()) }, ) } #[cfg(test)] mod tests { use crate::helpers::{check_assist, check_assist_not_applicable}; use super::*; #[test] fn test_inline_let_bind_literal_expr() { check_assist( inline_local_variable, " fn bar(a: usize) {} fn foo() { let a<|> = 1; a + 1; if a > 10 { } while a > 10 { } let b = a * 10; bar(a); }", " fn bar(a: usize) {} fn foo() { <|>1 + 1; if 1 > 10 { } while 1 > 10 { } let b = 1 * 10; bar(1); }", ); } #[test] fn test_inline_let_bind_bin_expr() { check_assist( inline_local_variable, " fn bar(a: usize) {} fn foo() { let a<|> = 1 + 1; a + 1; if a > 10 { } while a > 10 { } let b = a * 10; bar(a); }", " fn bar(a: usize) {} fn foo() { <|>(1 + 1) + 1; if (1 + 1) > 10 { } while (1 + 1) > 10 { } let b = (1 + 1) * 10; bar(1 + 1); }", ); } #[test] fn test_inline_let_bind_function_call_expr() { check_assist( inline_local_variable, " fn bar(a: usize) {} fn foo() { let a<|> = bar(1); a + 1; if a > 10 { } while a > 10 { } let b = a * 10; bar(a); }", " fn bar(a: usize) {} fn foo() { <|>bar(1) + 1; if bar(1) > 10 { } while bar(1) > 10 { } let b = bar(1) * 10; bar(bar(1)); }", ); } #[test] fn test_inline_let_bind_cast_expr() { check_assist( inline_local_variable, " fn bar(a: usize): usize { a } fn foo() { let a<|> = bar(1) as u64; a + 1; if a > 10 { } while a > 10 { } let b = a * 10; bar(a); }", " fn bar(a: usize): usize { a } fn foo() { <|>(bar(1) as u64) + 1; if (bar(1) as u64) > 10 { } while (bar(1) as u64) > 10 { } let b = (bar(1) as u64) * 10; bar(bar(1) as u64); }", ); } #[test] fn test_inline_let_bind_block_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = { 10 + 1 }; a + 1; if a > 10 { } while a > 10 { } let b = a * 10; bar(a); }", " fn foo() { <|>{ 10 + 1 } + 1; if { 10 + 1 } > 10 { } while { 10 + 1 } > 10 { } let b = { 10 + 1 } * 10; bar({ 10 + 1 }); }", ); } #[test] fn test_inline_let_bind_paren_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = ( 10 + 1 ); a + 1; if a > 10 { } while a > 10 { } let b = a * 10; bar(a); }", " fn foo() { <|>( 10 + 1 ) + 1; if ( 10 + 1 ) > 10 { } while ( 10 + 1 ) > 10 { } let b = ( 10 + 1 ) * 10; bar(( 10 + 1 )); }", ); } #[test] fn test_not_inline_mut_variable() { check_assist_not_applicable( inline_local_variable, " fn foo() { let mut a<|> = 1 + 1; a + 1; }", ); } #[test] fn test_call_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = bar(10 + 1); let b = a * 10; let c = a as usize; }", " fn foo() { <|>let b = bar(10 + 1) * 10; let c = bar(10 + 1) as usize; }", ); } #[test] fn test_index_expr() { check_assist( inline_local_variable, " fn foo() { let x = vec![1, 2, 3]; let a<|> = x[0]; let b = a * 10; let c = a as usize; }", " fn foo() { let x = vec![1, 2, 3]; <|>let b = x[0] * 10; let c = x[0] as usize; }", ); } #[test] fn test_method_call_expr() { check_assist( inline_local_variable, " fn foo() { let bar = vec![1]; let a<|> = bar.len(); let b = a * 10; let c = a as usize; }", " fn foo() { let bar = vec![1]; <|>let b = bar.len() * 10; let c = bar.len() as usize; }", ); } #[test] fn test_field_expr() { check_assist( inline_local_variable, " struct Bar { foo: usize } fn foo() { let bar = Bar { foo: 1 }; let a<|> = bar.foo; let b = a * 10; let c = a as usize; }", " struct Bar { foo: usize } fn foo() { let bar = Bar { foo: 1 }; <|>let b = bar.foo * 10; let c = bar.foo as usize; }", ); } #[test] fn test_try_expr() { check_assist( inline_local_variable, " fn foo() -> Option { let bar = Some(1); let a<|> = bar?; let b = a * 10; let c = a as usize; None }", " fn foo() -> Option { let bar = Some(1); <|>let b = bar? * 10; let c = bar? as usize; None }", ); } #[test] fn test_ref_expr() { check_assist( inline_local_variable, " fn foo() { let bar = 10; let a<|> = &bar; let b = a * 10; }", " fn foo() { let bar = 10; <|>let b = &bar * 10; }", ); } #[test] fn test_tuple_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = (10, 20); let b = a[0]; }", " fn foo() { <|>let b = (10, 20)[0]; }", ); } #[test] fn test_array_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = [1, 2, 3]; let b = a.len(); }", " fn foo() { <|>let b = [1, 2, 3].len(); }", ); } #[test] fn test_paren() { check_assist( inline_local_variable, " fn foo() { let a<|> = (10 + 20); let b = a * 10; let c = a as usize; }", " fn foo() { <|>let b = (10 + 20) * 10; let c = (10 + 20) as usize; }", ); } #[test] fn test_path_expr() { check_assist( inline_local_variable, " fn foo() { let d = 10; let a<|> = d; let b = a * 10; let c = a as usize; }", " fn foo() { let d = 10; <|>let b = d * 10; let c = d as usize; }", ); } #[test] fn test_block_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = { 10 }; let b = a * 10; let c = a as usize; }", " fn foo() { <|>let b = { 10 } * 10; let c = { 10 } as usize; }", ); } #[test] fn test_used_in_different_expr1() { check_assist( inline_local_variable, " fn foo() { let a<|> = 10 + 20; let b = a * 10; let c = (a, 20); let d = [a, 10]; let e = (a); }", " fn foo() { <|>let b = (10 + 20) * 10; let c = (10 + 20, 20); let d = [10 + 20, 10]; let e = (10 + 20); }", ); } #[test] fn test_used_in_for_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = vec![10, 20]; for i in a {} }", " fn foo() { <|>for i in vec![10, 20] {} }", ); } #[test] fn test_used_in_while_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = 1 > 0; while a {} }", " fn foo() { <|>while 1 > 0 {} }", ); } #[test] fn test_used_in_break_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = 1 + 1; loop { break a; } }", " fn foo() { <|>loop { break 1 + 1; } }", ); } #[test] fn test_used_in_return_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = 1 > 0; return a; }", " fn foo() { <|>return 1 > 0; }", ); } #[test] fn test_used_in_match_expr() { check_assist( inline_local_variable, " fn foo() { let a<|> = 1 > 0; match a {} }", " fn foo() { <|>match 1 > 0 {} }", ); } }