1 //! Contains utility functions to generate suggestions.
2 #![deny(clippy::missing_docs_in_private_items)]
5 use crate::source::{snippet, snippet_opt, snippet_with_context, snippet_with_macro_callsite};
6 use rustc_ast::util::parser::AssocOp;
7 use rustc_ast::{ast, token};
8 use rustc_ast_pretty::pprust::token_kind_to_string;
9 use rustc_errors::Applicability;
11 use rustc_lint::{EarlyContext, LateContext, LintContext};
12 use rustc_span::source_map::{CharPos, Span};
13 use rustc_span::{BytePos, Pos, SyntaxContext};
15 use std::convert::TryInto;
16 use std::fmt::Display;
17 use std::ops::{Add, Neg, Not, Sub};
19 /// A helper type to build suggestion correctly handling parenthesis.
20 #[derive(Clone, PartialEq)]
22 /// An expression that never needs parenthesis such as `1337` or `[0; 42]`.
23 NonParen(Cow<'a, str>),
24 /// An expression that does not fit in other variants.
25 MaybeParen(Cow<'a, str>),
26 /// A binary operator expression, including `as`-casts and explicit type
28 BinOp(AssocOp, Cow<'a, str>),
31 /// Literal constant `0`, for convenience.
32 pub const ZERO: Sugg<'static> = Sugg::NonParen(Cow::Borrowed("0"));
33 /// Literal constant `1`, for convenience.
34 pub const ONE: Sugg<'static> = Sugg::NonParen(Cow::Borrowed("1"));
35 /// a constant represents an empty string, for convenience.
36 pub const EMPTY: Sugg<'static> = Sugg::NonParen(Cow::Borrowed(""));
38 impl Display for Sugg<'_> {
39 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
41 Sugg::NonParen(ref s) | Sugg::MaybeParen(ref s) | Sugg::BinOp(_, ref s) => s.fmt(f),
46 #[allow(clippy::wrong_self_convention)] // ok, because of the function `as_ty` method
48 /// Prepare a suggestion from an expression.
49 pub fn hir_opt(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> Option<Self> {
50 snippet_opt(cx, expr.span).map(|snippet| {
51 let snippet = Cow::Owned(snippet);
52 Self::hir_from_snippet(expr, snippet)
56 /// Convenience function around `hir_opt` for suggestions with a default
58 pub fn hir(cx: &LateContext<'_>, expr: &hir::Expr<'_>, default: &'a str) -> Self {
59 Self::hir_opt(cx, expr).unwrap_or(Sugg::NonParen(Cow::Borrowed(default)))
62 /// Same as `hir`, but it adapts the applicability level by following rules:
64 /// - Applicability level `Unspecified` will never be changed.
65 /// - If the span is inside a macro, change the applicability level to `MaybeIncorrect`.
66 /// - If the default value is used and the applicability level is `MachineApplicable`, change it
69 pub fn hir_with_applicability(
73 applicability: &mut Applicability,
75 if *applicability != Applicability::Unspecified && expr.span.from_expansion() {
76 *applicability = Applicability::MaybeIncorrect;
78 Self::hir_opt(cx, expr).unwrap_or_else(|| {
79 if *applicability == Applicability::MachineApplicable {
80 *applicability = Applicability::HasPlaceholders;
82 Sugg::NonParen(Cow::Borrowed(default))
86 /// Same as `hir`, but will use the pre expansion span if the `expr` was in a macro.
87 pub fn hir_with_macro_callsite(cx: &LateContext<'_>, expr: &hir::Expr<'_>, default: &'a str) -> Self {
88 let snippet = snippet_with_macro_callsite(cx, expr.span, default);
90 Self::hir_from_snippet(expr, snippet)
93 /// Same as `hir`, but first walks the span up to the given context. This will result in the
94 /// macro call, rather then the expansion, if the span is from a child context. If the span is
95 /// not from a child context, it will be used directly instead.
97 /// e.g. Given the expression `&vec![]`, getting a snippet from the span for `vec![]` as a HIR
98 /// node would result in `box []`. If given the context of the address of expression, this
99 /// function will correctly get a snippet of `vec![]`.
100 pub fn hir_with_context(
101 cx: &LateContext<'_>,
102 expr: &hir::Expr<'_>,
105 applicability: &mut Applicability,
107 let (snippet, in_macro) = snippet_with_context(cx, expr.span, ctxt, default, applicability);
110 Sugg::NonParen(snippet)
112 Self::hir_from_snippet(expr, snippet)
116 /// Generate a suggestion for an expression with the given snippet. This is used by the `hir_*`
117 /// function variants of `Sugg`, since these use different snippet functions.
118 fn hir_from_snippet(expr: &hir::Expr<'_>, snippet: Cow<'a, str>) -> Self {
119 if let Some(range) = higher::range(expr) {
120 let op = match range.limits {
121 ast::RangeLimits::HalfOpen => AssocOp::DotDot,
122 ast::RangeLimits::Closed => AssocOp::DotDotEq,
124 return Sugg::BinOp(op, snippet);
128 hir::ExprKind::AddrOf(..)
129 | hir::ExprKind::Box(..)
130 | hir::ExprKind::If(..)
131 | hir::ExprKind::Closure(..)
132 | hir::ExprKind::Unary(..)
133 | hir::ExprKind::Match(..) => Sugg::MaybeParen(snippet),
134 hir::ExprKind::Continue(..)
135 | hir::ExprKind::Yield(..)
136 | hir::ExprKind::Array(..)
137 | hir::ExprKind::Block(..)
138 | hir::ExprKind::Break(..)
139 | hir::ExprKind::Call(..)
140 | hir::ExprKind::Field(..)
141 | hir::ExprKind::Index(..)
142 | hir::ExprKind::InlineAsm(..)
143 | hir::ExprKind::LlvmInlineAsm(..)
144 | hir::ExprKind::ConstBlock(..)
145 | hir::ExprKind::Lit(..)
146 | hir::ExprKind::Loop(..)
147 | hir::ExprKind::MethodCall(..)
148 | hir::ExprKind::Path(..)
149 | hir::ExprKind::Repeat(..)
150 | hir::ExprKind::Ret(..)
151 | hir::ExprKind::Struct(..)
152 | hir::ExprKind::Tup(..)
153 | hir::ExprKind::DropTemps(_)
154 | hir::ExprKind::Err => Sugg::NonParen(snippet),
155 hir::ExprKind::Assign(..) => Sugg::BinOp(AssocOp::Assign, snippet),
156 hir::ExprKind::AssignOp(op, ..) => Sugg::BinOp(hirbinop2assignop(op), snippet),
157 hir::ExprKind::Binary(op, ..) => Sugg::BinOp(AssocOp::from_ast_binop(higher::binop(op.node)), snippet),
158 hir::ExprKind::Cast(..) => Sugg::BinOp(AssocOp::As, snippet),
159 hir::ExprKind::Type(..) => Sugg::BinOp(AssocOp::Colon, snippet),
163 /// Prepare a suggestion from an expression.
164 pub fn ast(cx: &EarlyContext<'_>, expr: &ast::Expr, default: &'a str) -> Self {
165 use rustc_ast::ast::RangeLimits;
167 let snippet = if expr.span.from_expansion() {
168 snippet_with_macro_callsite(cx, expr.span, default)
170 snippet(cx, expr.span, default)
174 ast::ExprKind::AddrOf(..)
175 | ast::ExprKind::Box(..)
176 | ast::ExprKind::Closure(..)
177 | ast::ExprKind::If(..)
178 | ast::ExprKind::Let(..)
179 | ast::ExprKind::Unary(..)
180 | ast::ExprKind::Match(..) => Sugg::MaybeParen(snippet),
181 ast::ExprKind::Async(..)
182 | ast::ExprKind::Block(..)
183 | ast::ExprKind::Break(..)
184 | ast::ExprKind::Call(..)
185 | ast::ExprKind::Continue(..)
186 | ast::ExprKind::Yield(..)
187 | ast::ExprKind::Field(..)
188 | ast::ExprKind::ForLoop(..)
189 | ast::ExprKind::Index(..)
190 | ast::ExprKind::InlineAsm(..)
191 | ast::ExprKind::LlvmInlineAsm(..)
192 | ast::ExprKind::ConstBlock(..)
193 | ast::ExprKind::Lit(..)
194 | ast::ExprKind::Loop(..)
195 | ast::ExprKind::MacCall(..)
196 | ast::ExprKind::MethodCall(..)
197 | ast::ExprKind::Paren(..)
198 | ast::ExprKind::Underscore
199 | ast::ExprKind::Path(..)
200 | ast::ExprKind::Repeat(..)
201 | ast::ExprKind::Ret(..)
202 | ast::ExprKind::Struct(..)
203 | ast::ExprKind::Try(..)
204 | ast::ExprKind::TryBlock(..)
205 | ast::ExprKind::Tup(..)
206 | ast::ExprKind::Array(..)
207 | ast::ExprKind::While(..)
208 | ast::ExprKind::Await(..)
209 | ast::ExprKind::Err => Sugg::NonParen(snippet),
210 ast::ExprKind::Range(.., RangeLimits::HalfOpen) => Sugg::BinOp(AssocOp::DotDot, snippet),
211 ast::ExprKind::Range(.., RangeLimits::Closed) => Sugg::BinOp(AssocOp::DotDotEq, snippet),
212 ast::ExprKind::Assign(..) => Sugg::BinOp(AssocOp::Assign, snippet),
213 ast::ExprKind::AssignOp(op, ..) => Sugg::BinOp(astbinop2assignop(op), snippet),
214 ast::ExprKind::Binary(op, ..) => Sugg::BinOp(AssocOp::from_ast_binop(op.node), snippet),
215 ast::ExprKind::Cast(..) => Sugg::BinOp(AssocOp::As, snippet),
216 ast::ExprKind::Type(..) => Sugg::BinOp(AssocOp::Colon, snippet),
220 /// Convenience method to create the `<lhs> && <rhs>` suggestion.
221 pub fn and(self, rhs: &Self) -> Sugg<'static> {
222 make_binop(ast::BinOpKind::And, &self, rhs)
225 /// Convenience method to create the `<lhs> & <rhs>` suggestion.
226 pub fn bit_and(self, rhs: &Self) -> Sugg<'static> {
227 make_binop(ast::BinOpKind::BitAnd, &self, rhs)
230 /// Convenience method to create the `<lhs> as <rhs>` suggestion.
231 pub fn as_ty<R: Display>(self, rhs: R) -> Sugg<'static> {
232 make_assoc(AssocOp::As, &self, &Sugg::NonParen(rhs.to_string().into()))
235 /// Convenience method to create the `&<expr>` suggestion.
236 pub fn addr(self) -> Sugg<'static> {
240 /// Convenience method to create the `&mut <expr>` suggestion.
241 pub fn mut_addr(self) -> Sugg<'static> {
242 make_unop("&mut ", self)
245 /// Convenience method to create the `*<expr>` suggestion.
246 pub fn deref(self) -> Sugg<'static> {
250 /// Convenience method to create the `&*<expr>` suggestion. Currently this
251 /// is needed because `sugg.deref().addr()` produces an unnecessary set of
252 /// parentheses around the deref.
253 pub fn addr_deref(self) -> Sugg<'static> {
254 make_unop("&*", self)
257 /// Convenience method to create the `&mut *<expr>` suggestion. Currently
258 /// this is needed because `sugg.deref().mut_addr()` produces an unnecessary
259 /// set of parentheses around the deref.
260 pub fn mut_addr_deref(self) -> Sugg<'static> {
261 make_unop("&mut *", self)
264 /// Convenience method to transform suggestion into a return call
265 pub fn make_return(self) -> Sugg<'static> {
266 Sugg::NonParen(Cow::Owned(format!("return {}", self)))
269 /// Convenience method to transform suggestion into a block
270 /// where the suggestion is a trailing expression
271 pub fn blockify(self) -> Sugg<'static> {
272 Sugg::NonParen(Cow::Owned(format!("{{ {} }}", self)))
275 /// Convenience method to create the `<lhs>..<rhs>` or `<lhs>...<rhs>`
278 pub fn range(self, end: &Self, limit: ast::RangeLimits) -> Sugg<'static> {
280 ast::RangeLimits::HalfOpen => make_assoc(AssocOp::DotDot, &self, end),
281 ast::RangeLimits::Closed => make_assoc(AssocOp::DotDotEq, &self, end),
285 /// Adds parenthesis to any expression that might need them. Suitable to the
286 /// `self` argument of a method call
287 /// (e.g., to build `bar.foo()` or `(1 + 2).foo()`).
288 pub fn maybe_par(self) -> Self {
290 Sugg::NonParen(..) => self,
291 // `(x)` and `(x).y()` both don't need additional parens.
292 Sugg::MaybeParen(sugg) => {
293 if has_enclosing_paren(&sugg) {
294 Sugg::MaybeParen(sugg)
296 Sugg::NonParen(format!("({})", sugg).into())
299 Sugg::BinOp(_, sugg) => {
300 if has_enclosing_paren(&sugg) {
303 Sugg::NonParen(format!("({})", sugg).into())
310 /// Return `true` if `sugg` is enclosed in parenthesis.
311 fn has_enclosing_paren(sugg: impl AsRef<str>) -> bool {
312 let mut chars = sugg.as_ref().chars();
313 if let Some('(') = chars.next() {
315 for c in &mut chars {
325 chars.next().is_none()
331 // Copied from the rust standart library, and then edited
332 macro_rules! forward_binop_impls_to_ref {
333 (impl $imp:ident, $method:ident for $t:ty, type Output = $o:ty) => {
334 impl $imp<$t> for &$t {
337 fn $method(self, other: $t) -> $o {
338 $imp::$method(self, &other)
342 impl $imp<&$t> for $t {
345 fn $method(self, other: &$t) -> $o {
346 $imp::$method(&self, other)
353 fn $method(self, other: $t) -> $o {
354 $imp::$method(&self, &other)
360 impl Add for &Sugg<'_> {
361 type Output = Sugg<'static>;
362 fn add(self, rhs: &Sugg<'_>) -> Sugg<'static> {
363 make_binop(ast::BinOpKind::Add, self, rhs)
367 impl Sub for &Sugg<'_> {
368 type Output = Sugg<'static>;
369 fn sub(self, rhs: &Sugg<'_>) -> Sugg<'static> {
370 make_binop(ast::BinOpKind::Sub, self, rhs)
374 forward_binop_impls_to_ref!(impl Add, add for Sugg<'_>, type Output = Sugg<'static>);
375 forward_binop_impls_to_ref!(impl Sub, sub for Sugg<'_>, type Output = Sugg<'static>);
377 impl Neg for Sugg<'_> {
378 type Output = Sugg<'static>;
379 fn neg(self) -> Sugg<'static> {
384 impl Not for Sugg<'_> {
385 type Output = Sugg<'static>;
386 fn not(self) -> Sugg<'static> {
391 /// Helper type to display either `foo` or `(foo)`.
392 struct ParenHelper<T> {
393 /// `true` if parentheses are needed.
395 /// The main thing to display.
399 impl<T> ParenHelper<T> {
400 /// Builds a `ParenHelper`.
401 fn new(paren: bool, wrapped: T) -> Self {
402 Self { paren, wrapped }
406 impl<T: Display> Display for ParenHelper<T> {
407 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
409 write!(f, "({})", self.wrapped)
416 /// Builds the string for `<op><expr>` adding parenthesis when necessary.
418 /// For convenience, the operator is taken as a string because all unary
419 /// operators have the same
421 pub fn make_unop(op: &str, expr: Sugg<'_>) -> Sugg<'static> {
422 Sugg::MaybeParen(format!("{}{}", op, expr.maybe_par()).into())
425 /// Builds the string for `<lhs> <op> <rhs>` adding parenthesis when necessary.
427 /// Precedence of shift operator relative to other arithmetic operation is
428 /// often confusing so
429 /// parenthesis will always be added for a mix of these.
430 pub fn make_assoc(op: AssocOp, lhs: &Sugg<'_>, rhs: &Sugg<'_>) -> Sugg<'static> {
431 /// Returns `true` if the operator is a shift operator `<<` or `>>`.
432 fn is_shift(op: AssocOp) -> bool {
433 matches!(op, AssocOp::ShiftLeft | AssocOp::ShiftRight)
436 /// Returns `true` if the operator is a arithmetic operator
437 /// (i.e., `+`, `-`, `*`, `/`, `%`).
438 fn is_arith(op: AssocOp) -> bool {
441 AssocOp::Add | AssocOp::Subtract | AssocOp::Multiply | AssocOp::Divide | AssocOp::Modulus
445 /// Returns `true` if the operator `op` needs parenthesis with the operator
446 /// `other` in the direction `dir`.
447 fn needs_paren(op: AssocOp, other: AssocOp, dir: Associativity) -> bool {
448 other.precedence() < op.precedence()
449 || (other.precedence() == op.precedence()
450 && ((op != other && associativity(op) != dir)
451 || (op == other && associativity(op) != Associativity::Both)))
452 || is_shift(op) && is_arith(other)
453 || is_shift(other) && is_arith(op)
456 let lhs_paren = if let Sugg::BinOp(lop, _) = *lhs {
457 needs_paren(op, lop, Associativity::Left)
462 let rhs_paren = if let Sugg::BinOp(rop, _) = *rhs {
463 needs_paren(op, rop, Associativity::Right)
468 let lhs = ParenHelper::new(lhs_paren, lhs);
469 let rhs = ParenHelper::new(rhs_paren, rhs);
470 let sugg = match op {
478 | AssocOp::GreaterEqual
487 | AssocOp::ShiftRight
488 | AssocOp::Subtract => format!(
491 op.to_ast_binop().expect("Those are AST ops").to_string(),
494 AssocOp::Assign => format!("{} = {}", lhs, rhs),
495 AssocOp::AssignOp(op) => format!("{} {}= {}", lhs, token_kind_to_string(&token::BinOp(op)), rhs),
496 AssocOp::As => format!("{} as {}", lhs, rhs),
497 AssocOp::DotDot => format!("{}..{}", lhs, rhs),
498 AssocOp::DotDotEq => format!("{}..={}", lhs, rhs),
499 AssocOp::Colon => format!("{}: {}", lhs, rhs),
502 Sugg::BinOp(op, sugg.into())
505 /// Convenience wrapper around `make_assoc` and `AssocOp::from_ast_binop`.
506 pub fn make_binop(op: ast::BinOpKind, lhs: &Sugg<'_>, rhs: &Sugg<'_>) -> Sugg<'static> {
507 make_assoc(AssocOp::from_ast_binop(op), lhs, rhs)
510 #[derive(PartialEq, Eq, Clone, Copy)]
511 /// Operator associativity.
513 /// The operator is both left-associative and right-associative.
515 /// The operator is left-associative.
517 /// The operator is not associative.
519 /// The operator is right-associative.
523 /// Returns the associativity/fixity of an operator. The difference with
524 /// `AssocOp::fixity` is that an operator can be both left and right associative
525 /// (such as `+`: `a + b + c == (a + b) + c == a + (b + c)`.
527 /// Chained `as` and explicit `:` type coercion never need inner parenthesis so
528 /// they are considered
531 fn associativity(op: AssocOp) -> Associativity {
532 use rustc_ast::util::parser::AssocOp::{
533 Add, As, Assign, AssignOp, BitAnd, BitOr, BitXor, Colon, Divide, DotDot, DotDotEq, Equal, Greater,
534 GreaterEqual, LAnd, LOr, Less, LessEqual, Modulus, Multiply, NotEqual, ShiftLeft, ShiftRight, Subtract,
538 Assign | AssignOp(_) => Associativity::Right,
539 Add | BitAnd | BitOr | BitXor | LAnd | LOr | Multiply | As | Colon => Associativity::Both,
540 Divide | Equal | Greater | GreaterEqual | Less | LessEqual | Modulus | NotEqual | ShiftLeft | ShiftRight
541 | Subtract => Associativity::Left,
542 DotDot | DotDotEq => Associativity::None,
546 /// Converts a `hir::BinOp` to the corresponding assigning binary operator.
547 fn hirbinop2assignop(op: hir::BinOp) -> AssocOp {
548 use rustc_ast::token::BinOpToken::{And, Caret, Minus, Or, Percent, Plus, Shl, Shr, Slash, Star};
550 AssocOp::AssignOp(match op.node {
551 hir::BinOpKind::Add => Plus,
552 hir::BinOpKind::BitAnd => And,
553 hir::BinOpKind::BitOr => Or,
554 hir::BinOpKind::BitXor => Caret,
555 hir::BinOpKind::Div => Slash,
556 hir::BinOpKind::Mul => Star,
557 hir::BinOpKind::Rem => Percent,
558 hir::BinOpKind::Shl => Shl,
559 hir::BinOpKind::Shr => Shr,
560 hir::BinOpKind::Sub => Minus,
569 | hir::BinOpKind::Or => panic!("This operator does not exist"),
573 /// Converts an `ast::BinOp` to the corresponding assigning binary operator.
574 fn astbinop2assignop(op: ast::BinOp) -> AssocOp {
575 use rustc_ast::ast::BinOpKind::{
576 Add, And, BitAnd, BitOr, BitXor, Div, Eq, Ge, Gt, Le, Lt, Mul, Ne, Or, Rem, Shl, Shr, Sub,
578 use rustc_ast::token::BinOpToken;
580 AssocOp::AssignOp(match op.node {
581 Add => BinOpToken::Plus,
582 BitAnd => BinOpToken::And,
583 BitOr => BinOpToken::Or,
584 BitXor => BinOpToken::Caret,
585 Div => BinOpToken::Slash,
586 Mul => BinOpToken::Star,
587 Rem => BinOpToken::Percent,
588 Shl => BinOpToken::Shl,
589 Shr => BinOpToken::Shr,
590 Sub => BinOpToken::Minus,
591 And | Eq | Ge | Gt | Le | Lt | Ne | Or => panic!("This operator does not exist"),
595 /// Returns the indentation before `span` if there are nothing but `[ \t]`
596 /// before it on its line.
597 fn indentation<T: LintContext>(cx: &T, span: Span) -> Option<String> {
598 let lo = cx.sess().source_map().lookup_char_pos(span.lo());
600 .get_line(lo.line - 1 /* line numbers in `Loc` are 1-based */)
602 if let Some((pos, _)) = line.char_indices().find(|&(_, c)| c != ' ' && c != '\t') {
603 // We can mix char and byte positions here because we only consider `[ \t]`.
604 if lo.col == CharPos(pos) {
605 Some(line[..pos].into())
615 /// Convenience extension trait for `DiagnosticBuilder`.
616 pub trait DiagnosticBuilderExt<T: LintContext> {
617 /// Suggests to add an attribute to an item.
619 /// Correctly handles indentation of the attribute and item.
624 /// diag.suggest_item_with_attr(cx, item, "#[derive(Default)]");
626 fn suggest_item_with_attr<D: Display + ?Sized>(
632 applicability: Applicability,
635 /// Suggest to add an item before another.
637 /// The item should not be indented (except for inner indentation).
642 /// diag.suggest_prepend_item(cx, item,
647 fn suggest_prepend_item(&mut self, cx: &T, item: Span, msg: &str, new_item: &str, applicability: Applicability);
649 /// Suggest to completely remove an item.
651 /// This will remove an item and all following whitespace until the next non-whitespace
652 /// character. This should work correctly if item is on the same indentation level as the
658 /// diag.suggest_remove_item(cx, item, "remove this")
660 fn suggest_remove_item(&mut self, cx: &T, item: Span, msg: &str, applicability: Applicability);
663 impl<T: LintContext> DiagnosticBuilderExt<T> for rustc_errors::DiagnosticBuilder<'_> {
664 fn suggest_item_with_attr<D: Display + ?Sized>(
670 applicability: Applicability,
672 if let Some(indent) = indentation(cx, item) {
673 let span = item.with_hi(item.lo());
675 self.span_suggestion(span, msg, format!("{}\n{}", attr, indent), applicability);
679 fn suggest_prepend_item(&mut self, cx: &T, item: Span, msg: &str, new_item: &str, applicability: Applicability) {
680 if let Some(indent) = indentation(cx, item) {
681 let span = item.with_hi(item.lo());
683 let mut first = true;
684 let new_item = new_item
691 format!("{}{}\n", indent, l)
694 .collect::<String>();
696 self.span_suggestion(span, msg, format!("{}\n{}", new_item, indent), applicability);
700 fn suggest_remove_item(&mut self, cx: &T, item: Span, msg: &str, applicability: Applicability) {
701 let mut remove_span = item;
702 let hi = cx.sess().source_map().next_point(remove_span).hi();
703 let fmpos = cx.sess().source_map().lookup_byte_offset(hi);
705 if let Some(ref src) = fmpos.sf.src {
706 let non_whitespace_offset = src[fmpos.pos.to_usize()..].find(|c| c != ' ' && c != '\t' && c != '\n');
708 if let Some(non_whitespace_offset) = non_whitespace_offset {
709 remove_span = remove_span
710 .with_hi(remove_span.hi() + BytePos(non_whitespace_offset.try_into().expect("offset too large")));
714 self.span_suggestion(remove_span, msg, String::new(), applicability);
722 use rustc_ast::util::parser::AssocOp;
723 use std::borrow::Cow;
725 const SUGGESTION: Sugg<'static> = Sugg::NonParen(Cow::Borrowed("function_call()"));
728 fn make_return_transform_sugg_into_a_return_call() {
729 assert_eq!("return function_call()", SUGGESTION.make_return().to_string());
733 fn blockify_transforms_sugg_into_a_block() {
734 assert_eq!("{ function_call() }", SUGGESTION.blockify().to_string());
738 fn binop_maybe_par() {
739 let sugg = Sugg::BinOp(AssocOp::Add, "(1 + 1)".into());
740 assert_eq!("(1 + 1)", sugg.maybe_par().to_string());
742 let sugg = Sugg::BinOp(AssocOp::Add, "(1 + 1) + (1 + 1)".into());
743 assert_eq!("((1 + 1) + (1 + 1))", sugg.maybe_par().to_string());