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match_wildcard_for_single_variants: don't produce bad suggestion

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This fixes a bug where match_wildcard_for_single_variants produced a
bad suggestion where besides the missing variant, one or more hidden
variants were left.

This also adds tests to the ui-tests match_wildcard_for_single_variants
and wildcard_enum_match_arm to make sure that the correct suggestion is
produced.
This commit is contained in:
flip1995 2021-07-01 12:35:16 +02:00
parent 0ffba7a684
commit fae7a09eea
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GPG key ID: 1CA0DF2AF59D68A5
6 changed files with 52 additions and 3 deletions
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5
clippy_lints/src/matches.rs
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@ -1033,6 +1033,7 @@ fn check_wild_enum_match(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>])
// Accumulate the variants which should be put in place of the wildcard because they're not
// already covered.
let has_hidden = adt_def.variants.iter().any(|x| is_hidden(cx, x));
let mut missing_variants: Vec<_> = adt_def.variants.iter().filter(|x| !is_hidden(cx, x)).collect();
let mut path_prefix = CommonPrefixSearcher::None;
@ -1118,7 +1119,7 @@ fn check_wild_enum_match(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>])
match missing_variants.as_slice() {
[] => (),
[x] if !adt_def.is_variant_list_non_exhaustive() => span_lint_and_sugg(
[x] if !adt_def.is_variant_list_non_exhaustive() && !has_hidden => span_lint_and_sugg(
cx,
MATCH_WILDCARD_FOR_SINGLE_VARIANTS,
wildcard_span,
@ -1129,7 +1130,7 @@ fn check_wild_enum_match(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>])
),
variants => {
let mut suggestions: Vec<_> = variants.iter().copied().map(format_suggestion).collect();
let message = if adt_def.is_variant_list_non_exhaustive() {
let message = if adt_def.is_variant_list_non_exhaustive() || has_hidden {
suggestions.push("_".into());
"wildcard matches known variants and will also match future added variants"
} else {