SemverQuery(
id: "enum_discriminants_undefined_non_exhaustive_variant",
human_readable_name: "enum's variants no longer have defined discriminants due to a non-exhaustive variant",
description: "A public enum's variants no longer have well-defined discriminants value due to a non-exhaustive variant.",
reference: Some("A public enum's variants no longer have well-defined discriminants due to a non-exhaustive variant. This breaks downstream code that accessed the discriminant via a numeric cast like `as isize`."),
required_update: Major,
lint_level: Deny,
reference_link: Some("https://doc.rust-lang.org/reference/items/enumerations.html#assigning-discriminant-values"),
query: r#"
{
CrateDiff {
baseline {
item {
... on Enum {
visibility_limit @filter(op: "=", value: ["$public"]) @output
enum_name: name @output @tag
attribute @fold @transform(op: "count") @filter(op: "=", value: ["$zero"]) {
content {
base @filter(op: "=", value: ["$repr"])
}
}
importable_path {
path @output @tag
public_api @filter(op: "=", value: ["$true"])
}
variant @fold @transform(op: "count") @filter(op: ">", value: ["$zero"]) {
discriminant {
value
}
}
variant @fold @transform(op: "count") @filter(op: "=", value: ["$zero"]) {
__typename @filter(op: "!=", value: ["$plain_variant"])
}
variant @fold @transform(op: "count") @filter(op: "=", value: ["$zero"]) {
attrs @filter(op: "contains", value: ["$non_exhaustive"])
}
}
}
}
current {
item {
... on Enum {
visibility_limit @filter(op: "=", value: ["$public"])
name @filter(op: "=", value: ["%enum_name"])
importable_path {
path @filter(op: "=", value: ["%path"])
public_api @filter(op: "=", value: ["$true"])
}
variant @fold @transform(op: "count") @filter(op: "=", value: ["$zero"]) {
__typename @filter(op: "!=", value: ["$plain_variant"])
}
variant @fold @transform(op: "count") @filter(op: ">", value: ["$zero"]) {
attrs @filter(op: "contains", value: ["$non_exhaustive"])
}
span_: span @optional {
filename @output
begin_line @output
end_line @output
}
}
}
}
}
}"#,
arguments: {
"public": "public",
"repr": "repr",
"non_exhaustive": "#[non_exhaustive]",
"plain_variant": "PlainVariant",
"zero": 0,
"true": true,
},
error_message: "An enum's variants no longer have well-defined discriminant values due to a non-exhaustive variant in the enum. This breaks downstream code that accesses discriminants via a numeric cast like `as isize`.",
per_result_error_template: Some("enum {{enum_name}} in {{span_filename}}:{{span_begin_line}}"),
)