function_must_use_added.ron

SemverQuery(
    id: "function_must_use_added",
    human_readable_name: "function #[must_use] added",
    description: "A function has been marked with #[must_use].",
    required_update: Minor,
    lint_level: Deny,

    // TODO: Change the reference link to point to the cargo semver reference
    //       once it has a section on attribute #[must_use].
    reference_link: Some("https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute"),
    query: r#"
    {
        CrateDiff {
            current {
                item {
                    ... on Function {
                        visibility_limit @filter(op: "=", value: ["$public"])
                        name @output

                        importable_path {
                            path @tag @output
                            public_api @filter(op: "=", value: ["$true"])
                        }

                        attribute {
                            new_attr: raw_attribute @output
                            content {
                                base @filter(op: "=", value: ["$must_use"])
                            }
                        }

                        span_: span @optional {
                            filename @output
                            begin_line @output
                        }
                    }
                }
            }
            baseline {
                item {
                    ... on Function {
                        visibility_limit @filter(op: "=", value: ["$public"]) @output

                        importable_path {
                            path @filter(op: "=", value: ["%path"])
                            public_api @filter(op: "=", value: ["$true"])
                        }

                        attribute @fold @transform(op: "count") @filter(op: "=", value: ["$zero"]) {
                            content {
                                base @filter(op: "=", value: ["$must_use"])
                            }
                        }
                    }
                }
            }
        }
    }"#,
    arguments: {
        "public": "public",
        "must_use": "must_use",
        "true": true,
        "zero": 0,
    },
    error_message: "A function is now #[must_use]. Downstream crates that did not use its return value will get a compiler lint.",
    per_result_error_template: Some("function {{join \"::\" path}} in {{span_filename}}:{{span_begin_line}}"),
)