Enum WasmError 

pub enum WasmError {
    LoadFailed {
        path: PathBuf,
        source: Error,
        suggestion: Option<String>,
    },
    FunctionNotFound {
        function: String,
        module: String,
        suggestion: Option<String>,
    },
    GuestError {
        code: i32,
        message: Option<String>,
    },
    SerializationFailed(String),
    MemoryAccessFailed {
        reason: String,
    },
}

Errors related to loading and executing WASM plugins

Only available when the wasm-plugins feature is enabled. These errors occur when loading a .wasm module, validating its mandatory exports, or invoking a guest function across the host/guest boundary. See WASM_PLUGIN_INTERFACE.md for the full ABI contract.

Variants

LoadFailed

The .wasm module could not be loaded or instantiated

Example

use dynamic_cli::error::WasmError;
use std::path::PathBuf;

let error = WasmError::LoadFailed {
    path: PathBuf::from("plugin.wasm"),
    source: anyhow::anyhow!("invalid magic number"),
    suggestion: Some("Verify the file is a valid WASM binary.".to_string()),
};
let msg = format!("{}", error);
assert!(msg.contains("plugin.wasm"));

Fields

path: PathBuf

source: Error

suggestion: Option<String>

Actionable hint surfaced to the user (not part of the Display string)

FunctionNotFound

A mandatory or mapped export is missing from the module

Mandatory exports are memory, dcli_alloc, dcli_dealloc, and the mapped business function. See WASM_PLUGIN_INTERFACE.md.

Example

use dynamic_cli::error::WasmError;

let error = WasmError::FunctionNotFound {
    function: "dcli_dealloc".to_string(),
    module: "plugin.wasm".to_string(),
    suggestion: Some(
        "Export `dcli_dealloc(ptr: i32, size: i32)` from the WASM module.".to_string()
    ),
};
let msg = format!("{}", error);
assert!(msg.contains("dcli_dealloc"));

Fields

function: String

module: String

suggestion: Option<String>

Actionable hint surfaced to the user (not part of the Display string)

GuestError

The guest function returned a non-zero error code

message is populated from dcli_last_error_message() when the module exports it; otherwise None.

Example

use dynamic_cli::error::WasmError;

let error = WasmError::GuestError {
    code: 1,
    message: Some("invalid argument".to_string()),
};
let msg = format!("{}", error);
assert!(msg.contains('1'));

Fields

code: i32

message: Option<String>

Detailed message from dcli_last_error_message(), if exported

SerializationFailed(String)

Failed to serialize handler arguments before crossing the WASM boundary

Example

use dynamic_cli::error::WasmError;

let error = WasmError::SerializationFailed("unsupported map key type".to_string());
let msg = format!("{}", error);
assert!(msg.contains("unsupported map key type"));

MemoryAccessFailed

Failed to read from or write to the guest’s linear memory

Example

use dynamic_cli::error::WasmError;

let error = WasmError::MemoryAccessFailed {
    reason: "write out of bounds".to_string(),
};
let msg = format!("{}", error);
assert!(msg.contains("out of bounds"));

Fields

reason: String

Implementations

impl WasmError

pub fn missing_mandatory_export(function: &str, module: &str) -> Self

Create a FunctionNotFound error for a missing mandatory export

The suggestion names the exact signature expected for the missing export, taken from WASM_PLUGIN_INTERFACE.md.

Example

use dynamic_cli::error::WasmError;

let error = WasmError::missing_mandatory_export("dcli_alloc", "plugin.wasm");
match error {
    WasmError::FunctionNotFound { suggestion, .. } => {
        assert!(suggestion.is_some());
    }
    _ => panic!("wrong variant"),
}

pub fn guest_error_without_message(code: i32) -> Self

Create a GuestError from a raw error code, without a detailed message

Used when the module does not export dcli_last_error_message.

Example

use dynamic_cli::error::WasmError;

let error = WasmError::guest_error_without_message(2);
match error {
    WasmError::GuestError { code, message } => {
        assert_eq!(code, 2);
        assert!(message.is_none());
    }
    _ => panic!("wrong variant"),
}

Trait Implementations

impl Debug for WasmError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for WasmError

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for WasmError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<WasmError> for DynamicCliError

fn from(source: WasmError) -> Self

Converts to this type from the input type.