thrift/compiler/generate/templates/rust/lib/errors.mustache

{{!

  Copyright (c) Facebook, Inc. and its affiliates.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

}}
    {{#service:interactions}}{{>lib/errors}}
    {{/service:interactions}}
    /// Errors for {{service:name}} functions.
    pub mod {{service:snake}} {

        {{#service:rust_exceptions}}
        pub trait As{{#rust_exception:type}}{{type:rust_name}}{{/rust_exception:type}} {
            fn as_{{#rust_exception:type}}{{type:rust_name_snake}}{{/rust_exception:type}}(&self) -> Option<&{{#rust_exception:type}}{{>lib/type}}{{/rust_exception:type}}>;
        }

        impl As{{#rust_exception:type}}{{type:rust_name}}{{/rust_exception:type}} for ::anyhow::Error {
            fn as_{{#rust_exception:type}}{{type:rust_name_snake}}{{/rust_exception:type}}(&self) -> Option<&{{#rust_exception:type}}{{>lib/type}}{{/rust_exception:type}}> {
                for cause in self.chain() {
                {{#rust_exception:functions}}
                {{#rust_exception_function:function}}
                    if let Some({{function:upcamel}}Error::{{#rust_exception_function:field}}{{field:rust_name}}{{/rust_exception_function:field}}(e)) = cause.downcast_ref::<{{function:upcamel}}Error>() {
                        return Some(e);
                    }
                {{/rust_exception_function:function}}
                {{/rust_exception:functions}}
                }
                None
            }
        }

        {{/service:rust_exceptions}}
        {{#service:rustFunctions}}
        {{^function:starts_interaction?}}
        {{#function:exceptions?}}
        /// Errors for {{function:rust_name}} (client side).
        #[derive(Debug, ::thiserror::Error)]
        pub enum {{function:upcamel}}Error {
            {{#function:exceptions}}
            #[error("{{service:name}}::{{function:rust_name}} failed with {0:?}")]
            {{field:rust_name}}({{#field:type}}{{>lib/type}}{{/field:type}}),
            {{/function:exceptions}}
            #[error("Application exception: {0:?}")]
            ApplicationException(::fbthrift::types::ApplicationException),
            #[error("{0}")]
            ThriftError(::anyhow::Error),
        }

        {{#function:uniqueExceptions}}
        impl ::std::convert::From<{{#field:type}}{{>lib/type}}{{/field:type}}> for {{function:upcamel}}Error {
            fn from(e: {{#field:type}}{{>lib/type}}{{/field:type}}) -> Self {
                {{function:upcamel}}Error::{{field:rust_name}}(e)
            }
        }

        impl As{{#field:type}}{{type:rust_name}}{{/field:type}} for {{function:upcamel}}Error {
            fn as_{{#field:type}}{{type:rust_name_snake}}{{/field:type}}(&self) -> Option<&{{#field:type}}{{>lib/type}}{{/field:type}}> {
                match self {
                    {{function:upcamel}}Error::{{field:rust_name}}(inner) => Some(inner),
                    _ => None,
                }
            }
        }

        {{/function:uniqueExceptions}}
        impl ::std::convert::From<::anyhow::Error> for {{function:upcamel}}Error {
            fn from(err: ::anyhow::Error) -> Self {
                {{function:upcamel}}Error::ThriftError(err)
            }
        }

        impl ::std::convert::From<::fbthrift::ApplicationException> for {{function:upcamel}}Error {
            fn from(ae: ::fbthrift::ApplicationException) -> Self {
                {{function:upcamel}}Error::ApplicationException(ae)
            }
        }
        {{/function:exceptions?}}
        {{^function:exceptions?}}
        pub type {{function:upcamel}}Error = ::fbthrift::NonthrowingFunctionError;

        {{/function:exceptions?}}
        {{^function:returns_stream?}}
        impl ::std::convert::From<{{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn> for
            ::std::result::Result<{{#function:return_type}}{{>lib/type}}{{/function:return_type}}, {{function:upcamel}}Error>
        {
            fn from(e: {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn) -> Self {
                match e {
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn::Success(res) =>
                        ::std::result::Result::Ok(res),
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn::ApplicationException(aexn) =>
                        ::std::result::Result::Err({{function:upcamel}}Error::ApplicationException(aexn)),
                    {{#function:exceptions}}
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn::{{field:rust_name}}(exn) =>
                        ::std::result::Result::Err({{function:upcamel}}Error::{{field:rust_name}}(exn)),
                    {{/function:exceptions}}
                }
            }
        }

        {{/function:returns_stream?}}{{!
        }}{{#function:returns_stream?}}{{!
        }}{{#function:stream_has_first_response?}}
        impl ::std::convert::From<{{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn> for
            ::std::result::Result<{{>lib/function_stream_first_response_type}}, {{function:upcamel}}Error>
        {
            fn from(e: {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn) -> Self {
                match e {
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn::Success(res) =>
                        ::std::result::Result::Ok(res),
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn::ApplicationException(aexn) =>
                        ::std::result::Result::Err({{function:upcamel}}Error::ApplicationException(aexn)),
                    {{#function:exceptions}}
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn::{{field:rust_name}}(exn) =>
                        ::std::result::Result::Err({{function:upcamel}}Error::{{field:rust_name}}(exn)),
                    {{/function:exceptions}}
                }
            }
        }

        {{/function:stream_has_first_response?}}{{!
        }}{{#function:stream_exceptions?}}
        #[derive(Debug, ::thiserror::Error)]
        pub enum {{function:upcamel}}StreamError {
            {{#function:stream_exceptions}}
            #[error("{{service:name}}::{{function:rust_name}} stream failed with {0:?}")]
            {{field:rust_name}}({{#field:type}}{{>lib/type}}{{/field:type}}),
            {{/function:stream_exceptions}}
            #[error("Application exception: {0:?}")]
            ApplicationException(::fbthrift::types::ApplicationException),
            #[error("{0}")]
            ThriftError(::anyhow::Error),
        }

        {{#function:uniqueStreamExceptions}}
        impl ::std::convert::From<{{#field:type}}{{>lib/type}}{{/field:type}}> for {{function:upcamel}}StreamError {
            fn from(e: {{#field:type}}{{>lib/type}}{{/field:type}}) -> Self {
                {{function:upcamel}}StreamError::{{field:rust_name}}(e)
            }
        }

        {{/function:uniqueStreamExceptions}}
        impl ::std::convert::From<::anyhow::Error> for {{function:upcamel}}StreamError {
            fn from(err: ::anyhow::Error) -> Self {
                {{function:upcamel}}StreamError::ThriftError(err)
            }
        }

        impl ::std::convert::From<::fbthrift::ApplicationException> for {{function:upcamel}}StreamError {
            fn from(ae: ::fbthrift::ApplicationException) -> Self {
                {{function:upcamel}}StreamError::ApplicationException(ae)
            }
        }

        {{/function:stream_exceptions?}}
        {{^function:stream_exceptions?}}
        pub type {{function:upcamel}}StreamError = ::fbthrift::NonthrowingFunctionError;

        {{/function:stream_exceptions?}}
        impl ::std::convert::From<{{program:crate}}::services::{{service:snake}}::{{function:upcamel}}StreamExn> for
            ::std::result::Result<{{>lib/function_stream_elem_type}}, {{function:upcamel}}StreamError>
        {
            fn from(e: {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}StreamExn) -> Self {
                match e {
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}StreamExn::Success(res) =>
                        ::std::result::Result::Ok(res),
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}StreamExn::ApplicationException(aexn) =>
                        ::std::result::Result::Err({{function:upcamel}}StreamError::ApplicationException(aexn)),
                    {{#function:stream_exceptions}}
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}StreamExn::{{field:rust_name}}(exn) =>
                        ::std::result::Result::Err({{function:upcamel}}StreamError::{{field:rust_name}}(exn)),
                    {{/function:stream_exceptions}}
                }
            }
        }

        {{/function:returns_stream?}}
        {{/function:starts_interaction?}}
        {{/service:rustFunctions}}
    }

{{!newline}}