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//! Declare error types.
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use std::path::PathBuf;
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use tor_basic_utils::PathExt as _;
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use tor_error::{ErrorKind, HasKind};
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/// An error related to an option passed to Arti via a configuration
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/// builder.
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//
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// API NOTE: When possible, we should expose this error type rather than
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// wrapping it in `TorError`. It can provide specific information about  what
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// part of the configuration was invalid.
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//
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// This is part of the public API.
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#[derive(Debug, Clone, thiserror::Error)]
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#[non_exhaustive]
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pub enum ConfigBuildError {
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    /// A mandatory field was not present.
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    #[error("Field was not provided: {field}")]
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    MissingField {
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        /// The name of the missing field.
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        field: String,
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    },
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    /// A single field had a value that proved to be unusable.
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    #[error("Value of {field} was incorrect: {problem}")]
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    Invalid {
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        /// The name of the invalid field
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        field: String,
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        /// A description of the problem.
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        problem: String,
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    },
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    /// Multiple fields are inconsistent.
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    #[error("Fields {fields:?} are inconsistent: {problem}")]
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    Inconsistent {
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        /// The names of the inconsistent fields
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        fields: Vec<String>,
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        /// The problem that makes them inconsistent
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        problem: String,
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    },
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    /// The requested configuration is not supported in this build
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    #[error("Field {field:?} specifies a configuration not supported in this build: {problem}")]
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    // TODO should we report the cargo feature, if applicable?  And if so, of `arti`
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    // or of the underlying crate?  This seems like a can of worms.
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    NoCompileTimeSupport {
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        /// The names of the (primary) field requesting the unsupported configuration
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        field: String,
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        /// The description of the problem
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        problem: String,
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    },
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}
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impl From<derive_builder::UninitializedFieldError> for ConfigBuildError {
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    fn from(val: derive_builder::UninitializedFieldError) -> Self {
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        ConfigBuildError::MissingField {
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            field: val.field_name().to_string(),
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        }
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    }
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}
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impl From<derive_builder::SubfieldBuildError<ConfigBuildError>> for ConfigBuildError {
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    fn from(e: derive_builder::SubfieldBuildError<ConfigBuildError>) -> Self {
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        let (field, problem) = e.into_parts();
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        problem.within(field)
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    }
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}
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impl ConfigBuildError {
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    /// Return a new ConfigBuildError that prefixes its field name with
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    /// `prefix` and a dot.
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    #[must_use]
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    pub fn within(&self, prefix: &str) -> Self {
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        use ConfigBuildError::*;
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        let addprefix = |field: &str| format!("{}.{}", prefix, field);
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        match self {
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            MissingField { field } => MissingField {
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                field: addprefix(field),
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            },
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            Invalid { field, problem } => Invalid {
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                field: addprefix(field),
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                problem: problem.clone(),
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            },
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            Inconsistent { fields, problem } => Inconsistent {
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                fields: fields.iter().map(|f| addprefix(f)).collect(),
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                problem: problem.clone(),
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            },
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            NoCompileTimeSupport { field, problem } => NoCompileTimeSupport {
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                field: addprefix(field),
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                problem: problem.clone(),
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            },
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        }
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    }
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}
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impl HasKind for ConfigBuildError {
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    fn kind(&self) -> ErrorKind {
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        ErrorKind::InvalidConfig
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    }
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}
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/// An error caused when attempting to reconfigure an existing Arti client, or one of its modules.
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#[derive(Debug, Clone, thiserror::Error)]
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#[non_exhaustive]
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pub enum ReconfigureError {
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    /// Tried to change a field that cannot change on a running client.
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    #[error("Cannot change {field} on a running client.")]
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    CannotChange {
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        /// The field (or fields) that we tried to change.
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        field: String,
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    },
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    /// The requested configuration is not supported in this situation
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    ///
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    /// Something, probably discovered at runtime, is not compatible with
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    /// the specified configuration.
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    ///
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    /// This ought *not* to be returned when the configuration is simply not supported
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    /// by this build of arti -
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    /// that should be reported at config build type as `ConfigBuildError::Unsupported`.
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    #[error("Configuration not supported in this situation: {0}")]
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    UnsupportedSituation(String),
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    /// There was a programming error somewhere in our code, or the calling code.
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    #[error("Programming error")]
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    Bug(#[from] tor_error::Bug),
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}
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impl HasKind for ReconfigureError {
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    fn kind(&self) -> ErrorKind {
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        ErrorKind::InvalidConfigTransition
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    }
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}
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/// An error that occurs while trying to read and process our configuration.
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#[derive(Debug, Clone, thiserror::Error)]
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#[non_exhaustive]
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pub enum ConfigError {
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    /// We encoundered a problem checking file permissions (for example, no such file)
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    #[error("Problem accessing configuration file(s)")]
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    FileAccess(#[source] fs_mistrust::Error),
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    /// We encoundered a problem checking file permissions (for example, no such file)
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    ///
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    /// This variant name is misleading - see the docs for [`fs_mistrust::Error`].
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    /// Please use [`ConfigError::FileAccess`] instead.
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    #[deprecated = "use ConfigError::FileAccess instead"]
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    #[error("Problem accessing configuration file(s)")]
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    Permissions(#[source] fs_mistrust::Error),
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    /// Our underlying configuration library gave an error while loading our
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    /// configuration.
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    #[error("Couldn't load configuration")]
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    Load(#[source] ConfigLoadError),
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    /// Encountered an IO error with a configuration file or directory.
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    ///
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    /// Note that some IO errors may be reported as `Load` errors,
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    /// due to limitations of the underlying library.
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    #[error("IoError while {} {}", action, path.display_lossy())]
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    Io {
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        /// The action while we were trying to perform
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        action: &'static str,
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        /// The path we were trying to do it to.
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        path: PathBuf,
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        /// The underlying problem
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        #[source]
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        err: std::sync::Arc<std::io::Error>,
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    },
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}
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/// Wrapper for our an error type from our underlying configuration library.
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#[derive(Debug, Clone)]
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pub struct ConfigLoadError(figment::Error);
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impl ConfigError {
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    /// Wrap `err` as a ConfigError.
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    ///
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    /// This is not a From implementation, since we don't want to expose our
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    /// underlying configuration library.
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    pub(crate) fn from_cfg_err(err: figment::Error) -> Self {
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        // TODO: It would be lovely to extract IO errors from figment::Error
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        // and report them as Error::Io.  Unfortunately, it doesn't seem
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        // possible to do that given the design of figment::Error.
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        ConfigError::Load(ConfigLoadError(err))
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    }
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}
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impl std::fmt::Display for ConfigLoadError {
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    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
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        let s = self.0.to_string();
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        write!(f, "{}", s)?;
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        if s.contains("invalid escape") || s.contains("invalid hex escape") {
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            write!(f, "   (If you wanted to include a literal \\ character, you need to escape it by writing two in a row: \\\\)")?;
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        }
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        Ok(())
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    }
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}
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impl std::error::Error for ConfigLoadError {
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    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
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        Some(&self.0)
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    }
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}
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#[cfg(test)]
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mod test {
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    // @@ begin test lint list maintained by maint/add_warning @@
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    #![allow(clippy::bool_assert_comparison)]
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    #![allow(clippy::clone_on_copy)]
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    #![allow(clippy::dbg_macro)]
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    #![allow(clippy::mixed_attributes_style)]
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    #![allow(clippy::print_stderr)]
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    #![allow(clippy::print_stdout)]
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    #![allow(clippy::single_char_pattern)]
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    #![allow(clippy::unwrap_used)]
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    #![allow(clippy::unchecked_duration_subtraction)]
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    #![allow(clippy::useless_vec)]
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    #![allow(clippy::needless_pass_by_value)]
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    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
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    use super::*;
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    #[test]
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    fn within() {
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        let e1 = ConfigBuildError::MissingField {
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            field: "lettuce".to_owned(),
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        };
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        let e2 = ConfigBuildError::Invalid {
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            field: "tomato".to_owned(),
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            problem: "too crunchy".to_owned(),
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        };
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        let e3 = ConfigBuildError::Inconsistent {
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            fields: vec!["mayo".to_owned(), "avocado".to_owned()],
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            problem: "pick one".to_owned(),
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        };
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        assert_eq!(
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            &e1.within("sandwich").to_string(),
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            "Field was not provided: sandwich.lettuce"
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        );
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        assert_eq!(
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            &e2.within("sandwich").to_string(),
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            "Value of sandwich.tomato was incorrect: too crunchy"
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        );
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        assert_eq!(
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            &e3.within("sandwich").to_string(),
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            r#"Fields ["sandwich.mayo", "sandwich.avocado"] are inconsistent: pick one"#
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        );
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    }
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    #[derive(derive_builder::Builder, Debug, Clone)]
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    #[builder(build_fn(error = "ConfigBuildError"))]
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    #[allow(dead_code)]
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    struct Cephalopod {
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        // arms have suction cups for their whole length
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        arms: u8,
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        // Tentacles have suction cups at the ends
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        tentacles: u8,
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    }
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    #[test]
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    fn build_err() {
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        let squid = CephalopodBuilder::default().arms(8).tentacles(2).build();
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        let octopus = CephalopodBuilder::default().arms(8).build();
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        assert!(squid.is_ok());
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        let squid = squid.unwrap();
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        assert_eq!(squid.arms, 8);
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        assert_eq!(squid.tentacles, 2);
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        assert!(octopus.is_err());
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        assert_eq!(
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            &octopus.unwrap_err().to_string(),
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            "Field was not provided: tentacles"
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        );
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    }
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    #[derive(derive_builder::Builder, Debug)]
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    #[builder(build_fn(error = "ConfigBuildError"))]
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    #[allow(dead_code)]
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    struct Pet {
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        #[builder(sub_builder)]
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        best_friend: Cephalopod,
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    }
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    #[test]
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    fn build_subfield_err() {
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        let mut petb = PetBuilder::default();
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        petb.best_friend().tentacles(3);
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        let pet = petb.build();
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        assert_eq!(
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            pet.unwrap_err().to_string(),
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            "Field was not provided: best_friend.arms"
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        );
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    }
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}