86 lines
3.1 KiB
Rust
86 lines
3.1 KiB
Rust
use clippy_utils::diagnostics::span_lint_and_help;
|
|
use if_chain::if_chain;
|
|
use rustc_ast::ast::LitKind;
|
|
use rustc_hir::{Expr, ExprKind, PathSegment};
|
|
use rustc_lint::{LateContext, LateLintPass};
|
|
use rustc_middle::ty;
|
|
use rustc_session::{declare_lint_pass, declare_tool_lint};
|
|
use rustc_span::{source_map::Spanned, symbol::sym, Span};
|
|
|
|
declare_clippy_lint! {
|
|
/// **What it does:**
|
|
/// Checks for calls to `ends_with` with possible file extensions
|
|
/// and suggests to use a case-insensitive approach instead.
|
|
///
|
|
/// **Why is this bad?**
|
|
/// `ends_with` is case-sensitive and may not detect files with a valid extension.
|
|
///
|
|
/// **Known problems:** None.
|
|
///
|
|
/// **Example:**
|
|
///
|
|
/// ```rust
|
|
/// fn is_rust_file(filename: &str) -> bool {
|
|
/// filename.ends_with(".rs")
|
|
/// }
|
|
/// ```
|
|
/// Use instead:
|
|
/// ```rust
|
|
/// fn is_rust_file(filename: &str) -> bool {
|
|
/// filename.rsplit('.').next().map(|ext| ext.eq_ignore_ascii_case("rs")) == Some(true)
|
|
/// }
|
|
/// ```
|
|
pub CASE_SENSITIVE_FILE_EXTENSION_COMPARISONS,
|
|
pedantic,
|
|
"Checks for calls to ends_with with case-sensitive file extensions"
|
|
}
|
|
|
|
declare_lint_pass!(CaseSensitiveFileExtensionComparisons => [CASE_SENSITIVE_FILE_EXTENSION_COMPARISONS]);
|
|
|
|
fn check_case_sensitive_file_extension_comparison(ctx: &LateContext<'_>, expr: &Expr<'_>) -> Option<Span> {
|
|
if_chain! {
|
|
if let ExprKind::MethodCall(PathSegment { ident, .. }, _, [obj, extension, ..], span) = expr.kind;
|
|
if ident.as_str() == "ends_with";
|
|
if let ExprKind::Lit(Spanned { node: LitKind::Str(ext_literal, ..), ..}) = extension.kind;
|
|
if (2..=6).contains(&ext_literal.as_str().len());
|
|
if ext_literal.as_str().starts_with('.');
|
|
if ext_literal.as_str().chars().skip(1).all(|c| c.is_uppercase() || c.is_digit(10))
|
|
|| ext_literal.as_str().chars().skip(1).all(|c| c.is_lowercase() || c.is_digit(10));
|
|
then {
|
|
let mut ty = ctx.typeck_results().expr_ty(obj);
|
|
ty = match ty.kind() {
|
|
ty::Ref(_, ty, ..) => ty,
|
|
_ => ty
|
|
};
|
|
|
|
match ty.kind() {
|
|
ty::Str => {
|
|
return Some(span);
|
|
},
|
|
ty::Adt(&ty::AdtDef { did, .. }, _) => {
|
|
if ctx.tcx.is_diagnostic_item(sym::string_type, did) {
|
|
return Some(span);
|
|
}
|
|
},
|
|
_ => { return None; }
|
|
}
|
|
}
|
|
}
|
|
None
|
|
}
|
|
|
|
impl LateLintPass<'tcx> for CaseSensitiveFileExtensionComparisons {
|
|
fn check_expr(&mut self, ctx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
|
|
if let Some(span) = check_case_sensitive_file_extension_comparison(ctx, expr) {
|
|
span_lint_and_help(
|
|
ctx,
|
|
CASE_SENSITIVE_FILE_EXTENSION_COMPARISONS,
|
|
span,
|
|
"case-sensitive file extension comparison",
|
|
None,
|
|
"consider using a case-insensitive comparison instead",
|
|
);
|
|
}
|
|
}
|
|
}
|