# 0.0.145 Breaking Changes for Kizuna
###### tags: `HDK 0.0.145`

## Returning Errors
The custom guest error from string is now found in `WasmErrorInner`. Wrap the error in a `wasm_error!` macro (which also has the capability to display error line numbers).

Err(e) => return Err(wasm_error!(WasmErrorInner::Guest(String::from(e))))

Change the `error` util function from

pub fn error<T>(reason: &str) -> ExternResult<T> {
    Err(WasmError::Guest(String::from(reason)))
}

to

pub fn error<T>(reason: &str) -> ExternResult<T> {
    Err(wasm_error!(WasmErrorInner::Guest(String::from(reason))))
}

## Entry Definitions
### Entry Structures
Add this helper to entry structures

#[hdk_entry_helper]

Remove serde helper from entry structures

#[serde(rename_all = "camelCase")]

Exclude `Serialize`, `Desiarialize`, `SerializedBytes`, and `Debug` from the derive in entry structures.`Clone` and `From` can still be derived.

#[derive(Clone, From)]

Sample entry structure:

#[derive(Clone, From)]
#[hdk_entry_helper]
pub struct P2PMessage {
    pub author: AgentPubKey,
    pub receiver: AgentPubKey,
    payload: Payload,
    time_sent: Timestamp,
    reply_to: Option<EntryHash>,
}

Declaring EntryTypes

// pre 0.0.145
// in lib.rs
// entry_defs![
//     P2PMessage::entry_def(),
//     P2PMessageReceipt::entry_def(),
//     P2PFileBytes::entry_def(),
//     P2PMessagePin::entry_def()
// ];

// in contact.rs
// entry_def!(P2PMessage
//     EntryDef {
//         id: "p2pmessage".into(),
//         visibility: EntryVisibility::Private,
//         crdt_type: CrdtType,
//         required_validations: RequiredValidations::default(),
//         required_validation_type: RequiredValidationType::Element
//     }
// );

#[hdk_entry_defs]
#[unit_enum(UnitEntryTypes)]
pub enum EntryTypes {
    #[entry_def(required_validations = 5, visibility = "private")]
    P2PMessage(P2PMessage),
    ...
}

## Records and Actions
Change all instances of `Element` to `Record` and `Header` to `Action`. Might be easier to just Replace All.

Examples

Element -> Record
HeaderHash -> ActionHash

## Decode
`decode()` produces a `Result<<T>, SerializedBytesError>`. The `?` cannot be readily used as it produces a either a `<T>` or a `WasmError`. The `SerializedBytesError` cannot be directly converted to a WsmError.

Remove the `?` operator in decodes and add a match clause to filter the Result.

Sample code as used in signal decoding:

let signal_detail_result: Result<SignalDetails, SerializedBytesError> = signal.decode()?;
match signal_detail_result {
    Ok(signal_detail) => {
        emit_signal(&signal_detail)?;
        return Ok(())
    },
    Err(e) => return Err(wasm_error!(WasmErrorInner::Guest(String::from(e))))
}

## Macros
### create_entry
specify entry type taken from the `EntryTypes` enum declaration

// pre-0.0.145
// create_entry(alias.clone())?;
// return Ok(io);

match create_entry(&EntryTypes::Alias(alias.clone())) {
    Ok(_) => return Ok(io),
    Err(_) => return error("problems were encountered during creation of entry"),
}