46 lines
1.6 KiB
Rust
46 lines
1.6 KiB
Rust
use super::FOR_LOOPS_OVER_FALLIBLES;
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use crate::utils::{is_type_diagnostic_item, snippet, span_lint_and_help};
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use rustc_hir::{Expr, Pat};
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use rustc_lint::LateContext;
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use rustc_span::symbol::sym;
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/// Checks for `for` loops over `Option`s and `Result`s.
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pub(super) fn check(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>) {
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let ty = cx.typeck_results().expr_ty(arg);
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if is_type_diagnostic_item(cx, ty, sym::option_type) {
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span_lint_and_help(
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cx,
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FOR_LOOPS_OVER_FALLIBLES,
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arg.span,
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&format!(
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"for loop over `{0}`, which is an `Option`. This is more readably written as an \
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`if let` statement",
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snippet(cx, arg.span, "_")
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),
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None,
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&format!(
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"consider replacing `for {0} in {1}` with `if let Some({0}) = {1}`",
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snippet(cx, pat.span, "_"),
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snippet(cx, arg.span, "_")
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),
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);
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} else if is_type_diagnostic_item(cx, ty, sym::result_type) {
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span_lint_and_help(
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cx,
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FOR_LOOPS_OVER_FALLIBLES,
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arg.span,
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&format!(
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"for loop over `{0}`, which is a `Result`. This is more readably written as an \
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`if let` statement",
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snippet(cx, arg.span, "_")
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),
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None,
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&format!(
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"consider replacing `for {0} in {1}` with `if let Ok({0}) = {1}`",
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snippet(cx, pat.span, "_"),
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snippet(cx, arg.span, "_")
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),
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);
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}
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}
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