diff options
| -rw-r--r-- | clippy_lints/src/methods/read_line_without_trim.rs | 93 |
1 files changed, 62 insertions, 31 deletions
diff --git a/clippy_lints/src/methods/read_line_without_trim.rs b/clippy_lints/src/methods/read_line_without_trim.rs index 3b903ec5cdb..f4b4f73af56 100644 --- a/clippy_lints/src/methods/read_line_without_trim.rs +++ b/clippy_lints/src/methods/read_line_without_trim.rs @@ -5,9 +5,10 @@ use clippy_utils::source::snippet; use clippy_utils::ty::is_type_diagnostic_item; use clippy_utils::visitors::for_each_local_use_after_expr; use clippy_utils::{get_parent_expr, match_def_path}; +use rustc_ast::LitKind; use rustc_errors::Applicability; use rustc_hir::def::Res; -use rustc_hir::{Expr, ExprKind, QPath}; +use rustc_hir::{BinOpKind, Expr, ExprKind, QPath}; use rustc_lint::LateContext; use rustc_middle::ty::{self, Ty}; use rustc_span::sym; @@ -30,37 +31,67 @@ pub fn check(cx: &LateContext<'_>, call: &Expr<'_>, recv: &Expr<'_>, arg: &Expr< // now let's check if the first use of the string passed to `::read_line()` is // parsed into a type that will always fail if it has a trailing newline. for_each_local_use_after_expr(cx, local_id, call.hir_id, |expr| { - if let Some(parent) = get_parent_expr(cx, expr) - && let ExprKind::MethodCall(segment, .., span) = parent.kind - && segment.ident.name == sym!(parse) - && let parse_result_ty = cx.typeck_results().expr_ty(parent) - && is_type_diagnostic_item(cx, parse_result_ty, sym::Result) - && let ty::Adt(_, args) = parse_result_ty.kind() - && let Some(ok_ty) = args[0].as_type() - && parse_fails_on_trailing_newline(ok_ty) - { - let local_snippet = snippet(cx, expr.span, "<expr>"); - span_lint_and_then( - cx, - READ_LINE_WITHOUT_TRIM, - span, - "calling `.parse()` without trimming the trailing newline character", - |diag| { - diag.span_note( - call.span, - "call to `.read_line()` here, \ - which leaves a trailing newline character in the buffer, \ - which in turn will cause `.parse()` to fail", - ); + if let Some(parent) = get_parent_expr(cx, expr) { + if let ExprKind::MethodCall(segment, .., span) = parent.kind + && segment.ident.name == sym!(parse) + && let parse_result_ty = cx.typeck_results().expr_ty(parent) + && is_type_diagnostic_item(cx, parse_result_ty, sym::Result) + && let ty::Adt(_, substs) = parse_result_ty.kind() + && let Some(ok_ty) = substs[0].as_type() + && parse_fails_on_trailing_newline(ok_ty) + { + let local_snippet: std::borrow::Cow<'_, str> = snippet(cx, expr.span, "<expr>"); + span_lint_and_then( + cx, + READ_LINE_WITHOUT_TRIM, + span, + "calling `.parse()` without trimming the trailing newline character", + |diag| { + diag.span_note( + call.span, + "call to `.read_line()` here, \ + which leaves a trailing newline character in the buffer, \ + which in turn will cause `.parse()` to fail", + ); - diag.span_suggestion( - expr.span, - "try", - format!("{local_snippet}.trim_end()"), - Applicability::MachineApplicable, - ); - }, - ); + diag.span_suggestion( + expr.span, + "try", + format!("{local_snippet}.trim_end()"), + Applicability::MachineApplicable, + ); + }, + ); + } else if let ExprKind::Binary(binop, _, right) = parent.kind + && let BinOpKind::Eq = binop.node + && let ExprKind::Lit(lit) = right.kind + && let LitKind::Str(sym, _) = lit.node + && !sym.as_str().ends_with('\n') + { + span_lint_and_then( + cx, + READ_LINE_WITHOUT_TRIM, + parent.span, + "comparing a string literal without trimming the trailing newline character", + |diag| { + let local_snippet = snippet(cx, expr.span, "<expr>"); + + diag.span_note( + call.span, + "call to `.read_line()` here, \ + which leaves a trailing newline character in the buffer, \ + which in turn will cause the comparison to always fail", + ); + + diag.span_suggestion( + expr.span, + "try", + format!("{local_snippet}.trim_end()"), + Applicability::MachineApplicable, + ); + }, + ); + } } // only consider the first use to prevent this scenario: |