1 use hir::{known, AsAssocItem, Semantics};
5 node_ext::{block_as_lone_tail, preorder_expr},
10 use itertools::Itertools;
12 ast::{self, edit::AstNodeEdit, make, HasArgList},
13 ted, AstNode, SyntaxNode,
17 utils::{invert_boolean_expression, unwrap_trivial_block},
18 AssistContext, AssistId, AssistKind, Assists,
21 // Assist: convert_if_to_bool_then
23 // Converts an if expression into a corresponding `bool::then` call.
26 // # //- minicore: option
41 pub(crate) fn convert_if_to_bool_then(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
42 // todo, applies to match as well
43 let expr = ctx.find_node_at_offset::<ast::IfExpr>()?;
44 if !expr.if_token()?.text_range().contains_inclusive(ctx.offset()) {
48 let cond = expr.condition().filter(|cond| !cond.is_pattern_cond())?;
49 let cond = cond.expr()?;
50 let then = expr.then_branch()?;
51 let else_ = match expr.else_branch()? {
52 ast::ElseBranch::Block(b) => b,
53 ast::ElseBranch::IfExpr(_) => {
54 cov_mark::hit!(convert_if_to_bool_then_chain);
59 let (none_variant, some_variant) = option_variants(&ctx.sema, expr.syntax())?;
61 let (invert_cond, closure_body) = match (
62 block_is_none_variant(&ctx.sema, &then, none_variant),
63 block_is_none_variant(&ctx.sema, &else_, none_variant),
65 (invert @ true, false) => (invert, ast::Expr::BlockExpr(else_)),
66 (invert @ false, true) => (invert, ast::Expr::BlockExpr(then)),
70 if is_invalid_body(&ctx.sema, some_variant, &closure_body) {
71 cov_mark::hit!(convert_if_to_bool_then_pattern_invalid_body);
75 let target = expr.syntax().text_range();
77 AssistId("convert_if_to_bool_then", AssistKind::RefactorRewrite),
78 "Convert `if` expression to `bool::then` call",
81 let closure_body = closure_body.clone_for_update();
82 // Rewrite all `Some(e)` in tail position to `e`
83 let mut replacements = Vec::new();
84 for_each_tail_expr(&closure_body, &mut |e| {
86 ast::Expr::BreakExpr(e) => e.expr(),
87 e @ ast::Expr::CallExpr(_) => Some(e.clone()),
90 if let Some(ast::Expr::CallExpr(call)) = e {
91 if let Some(arg_list) = call.arg_list() {
92 if let Some(arg) = arg_list.args().next() {
93 replacements.push((call.syntax().clone(), arg.syntax().clone()));
98 replacements.into_iter().for_each(|(old, new)| ted::replace(old, new));
99 let closure_body = match closure_body {
100 ast::Expr::BlockExpr(block) => unwrap_trivial_block(block),
104 let cond = if invert_cond { invert_boolean_expression(cond) } else { cond };
105 let arg_list = make::arg_list(Some(make::expr_closure(None, closure_body)));
106 let mcall = make::expr_method_call(cond, make::name_ref("then"), arg_list);
107 builder.replace(target, mcall.to_string());
112 // Assist: convert_bool_then_to_if
114 // Converts a `bool::then` method call to an equivalent if expression.
117 // # //- minicore: bool_impl
119 // (0 == 0).then$0(|| val)
132 pub(crate) fn convert_bool_then_to_if(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
133 let name_ref = ctx.find_node_at_offset::<ast::NameRef>()?;
134 let mcall = name_ref.syntax().parent().and_then(ast::MethodCallExpr::cast)?;
135 let receiver = mcall.receiver()?;
136 let closure_body = mcall.arg_list()?.args().exactly_one().ok()?;
137 let closure_body = match closure_body {
138 ast::Expr::ClosureExpr(expr) => expr.body()?,
141 // Verify this is `bool::then` that is being called.
142 let func = ctx.sema.resolve_method_call(&mcall)?;
143 if func.name(ctx.sema.db).to_string() != "then" {
146 let assoc = func.as_assoc_item(ctx.sema.db)?;
147 match assoc.container(ctx.sema.db) {
148 hir::AssocItemContainer::Impl(impl_) if impl_.self_ty(ctx.sema.db).is_bool() => {}
152 let target = mcall.syntax().text_range();
154 AssistId("convert_bool_then_to_if", AssistKind::RefactorRewrite),
155 "Convert `bool::then` call to `if`",
158 let closure_body = match closure_body {
159 ast::Expr::BlockExpr(block) => block,
160 e => make::block_expr(None, Some(e)),
163 let closure_body = closure_body.clone_for_update();
164 // Wrap all tails in `Some(...)`
165 let none_path = make::expr_path(make::ext::ident_path("None"));
166 let some_path = make::expr_path(make::ext::ident_path("Some"));
167 let mut replacements = Vec::new();
168 for_each_tail_expr(&ast::Expr::BlockExpr(closure_body.clone()), &mut |e| {
170 ast::Expr::BreakExpr(e) => e.expr(),
171 ast::Expr::ReturnExpr(e) => e.expr(),
172 _ => Some(e.clone()),
174 if let Some(expr) = e {
176 expr.syntax().clone(),
177 make::expr_call(some_path.clone(), make::arg_list(Some(expr)))
183 replacements.into_iter().for_each(|(old, new)| ted::replace(old, new));
185 let cond = match &receiver {
186 ast::Expr::ParenExpr(expr) => expr.expr().unwrap_or(receiver),
189 let if_expr = make::expr_if(
190 make::condition(cond, None),
191 closure_body.reset_indent(),
192 Some(ast::ElseBranch::Block(make::block_expr(None, Some(none_path)))),
194 .indent(mcall.indent_level());
196 builder.replace(target, if_expr.to_string());
202 sema: &Semantics<RootDatabase>,
204 ) -> Option<(hir::Variant, hir::Variant)> {
205 let fam = FamousDefs(sema, sema.scope(expr).krate());
206 let option_variants = fam.core_option_Option()?.variants(sema.db);
207 match &*option_variants {
208 &[variant0, variant1] => Some(if variant0.name(sema.db) == known::None {
217 /// Traverses the expression checking if it contains `return` or `?` expressions or if any tail is not a `Some(expr)` expression.
218 /// If any of these conditions are met it is impossible to rewrite this as a `bool::then` call.
220 sema: &Semantics<RootDatabase>,
221 some_variant: hir::Variant,
224 let mut invalid = false;
225 preorder_expr(expr, &mut |e| {
227 matches!(e, syntax::WalkEvent::Enter(ast::Expr::TryExpr(_) | ast::Expr::ReturnExpr(_)));
231 for_each_tail_expr(expr, &mut |e| {
236 ast::Expr::BreakExpr(e) => e.expr(),
237 e @ ast::Expr::CallExpr(_) => Some(e.clone()),
240 if let Some(ast::Expr::CallExpr(call)) = e {
241 if let Some(ast::Expr::PathExpr(p)) = call.expr() {
242 let res = p.path().and_then(|p| sema.resolve_path(&p));
243 if let Some(hir::PathResolution::Def(hir::ModuleDef::Variant(v))) = res {
244 return invalid |= v != some_variant;
254 fn block_is_none_variant(
255 sema: &Semantics<RootDatabase>,
256 block: &ast::BlockExpr,
257 none_variant: hir::Variant,
259 block_as_lone_tail(block).and_then(|e| match e {
260 ast::Expr::PathExpr(pat) => match sema.resolve_path(&pat.path()?)? {
261 hir::PathResolution::Def(hir::ModuleDef::Variant(v)) => Some(v),
265 }) == Some(none_variant)
270 use crate::tests::{check_assist, check_assist_not_applicable};
275 fn convert_if_to_bool_then_simple() {
277 convert_if_to_bool_then,
297 fn convert_if_to_bool_then_invert() {
299 convert_if_to_bool_then,
319 fn convert_if_to_bool_then_none_none() {
320 check_assist_not_applicable(
321 convert_if_to_bool_then,
336 fn convert_if_to_bool_then_some_some() {
337 check_assist_not_applicable(
338 convert_if_to_bool_then,
353 fn convert_if_to_bool_then_mixed() {
354 check_assist_not_applicable(
355 convert_if_to_bool_then,
374 fn convert_if_to_bool_then_chain() {
375 cov_mark::check!(convert_if_to_bool_then_chain);
376 check_assist_not_applicable(
377 convert_if_to_bool_then,
394 fn convert_if_to_bool_then_pattern_cond() {
395 check_assist_not_applicable(
396 convert_if_to_bool_then,
400 if$0 let true = true {
411 fn convert_if_to_bool_then_pattern_invalid_body() {
412 cov_mark::check_count!(convert_if_to_bool_then_pattern_invalid_body, 2);
413 check_assist_not_applicable(
414 convert_if_to_bool_then,
417 fn make_me_an_option() -> Option<i32> { None }
431 check_assist_not_applicable(
432 convert_if_to_bool_then,
450 fn convert_bool_then_to_if_inapplicable() {
451 check_assist_not_applicable(
452 convert_bool_then_to_if,
454 //- minicore:bool_impl
460 check_assist_not_applicable(
461 convert_bool_then_to_if,
463 //- minicore:bool_impl
469 check_assist_not_applicable(
470 convert_bool_then_to_if,
472 //- minicore:bool_impl
474 true.t$0hen(|| 15, 15);
481 fn convert_bool_then_to_if_simple() {
483 convert_bool_then_to_if,
485 //- minicore:bool_impl
501 convert_bool_then_to_if,
503 //- minicore:bool_impl
523 fn convert_bool_then_to_if_tails() {
525 convert_bool_then_to_if,
527 //- minicore:bool_impl