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#![warn(missing_docs)]
#![deny(warnings)]
use failure::Fail;
use lambda_runtime_core::{start_with_config, EnvConfigProvider, HandlerError, LambdaErrorExt};
use serde;
use serde_json;
use std::fmt::Display;
use tokio::runtime::Runtime as TokioRuntime;
pub use lambda_runtime_core::Context;
pub mod error {
pub use lambda_runtime_core::{HandlerError, LambdaErrorExt, LambdaResultExt};
}
pub trait Handler<Event, Output, EventError> {
fn run(&mut self, event: Event, ctx: Context) -> Result<Output, EventError>;
}
impl<Function, Event, Output, EventError> Handler<Event, Output, EventError> for Function
where
Function: FnMut(Event, Context) -> Result<Output, EventError>,
EventError: Fail + LambdaErrorExt + Display + Send + Sync,
{
fn run(&mut self, event: Event, ctx: Context) -> Result<Output, EventError> {
(*self)(event, ctx)
}
}
fn wrap<Event, Output, EventError>(
mut h: impl Handler<Event, Output, EventError>,
) -> impl FnMut(Vec<u8>, Context) -> Result<Vec<u8>, HandlerError>
where
Event: serde::de::DeserializeOwned,
Output: serde::Serialize,
EventError: Fail + LambdaErrorExt + Display + Send + Sync,
{
move |ev, ctx| {
let event: Event = serde_json::from_slice(&ev)?;
match h.run(event, ctx) {
Ok(out) => {
let out_bytes = serde_json::to_vec(&out)?;
Ok(out_bytes)
}
Err(e) => Err(HandlerError::new(e)),
}
}
}
pub fn start<Event, Output, EventError>(f: impl Handler<Event, Output, EventError>, runtime: Option<TokioRuntime>)
where
Event: serde::de::DeserializeOwned,
Output: serde::Serialize,
EventError: Fail + LambdaErrorExt + Display + Send + Sync,
{
let wrapped = wrap(f);
start_with_config(wrapped, &EnvConfigProvider::default(), runtime)
}
#[macro_export]
macro_rules! lambda {
($handler:ident) => {
$crate::start($handler, None)
};
($handler:ident, $runtime:expr) => {
$crate::start($handler, Some($runtime))
};
($handler:expr) => {
$crate::start($handler, None)
};
($handler:expr, $runtime:expr) => {
$crate::start($handler, Some($runtime))
};
}
#[cfg(test)]
pub(crate) mod tests {
use super::*;
use lambda_runtime_core::Context;
use serde_derive::{Deserialize, Serialize};
use serde_json;
fn test_context() -> Context {
Context {
memory_limit_in_mb: 128,
function_name: "test_func".to_string(),
function_version: "$LATEST".to_string(),
invoked_function_arn: "arn:aws:lambda".to_string(),
aws_request_id: "123".to_string(),
xray_trace_id: Some("123".to_string()),
log_stream_name: "logStream".to_string(),
log_group_name: "logGroup".to_string(),
client_context: Option::default(),
identity: Option::default(),
deadline: 0,
}
}
#[derive(Serialize, Deserialize)]
struct Input {
name: String,
}
#[derive(Serialize, Deserialize)]
struct Output {
msg: String,
}
#[test]
fn runtime_invokes_handler() {
let handler_ok = |_e: Input, _c: Context| -> Result<Output, HandlerError> {
Ok(Output {
msg: "hello".to_owned(),
})
};
let mut wrapped_ok = wrap(handler_ok);
let input = Input {
name: "test".to_owned(),
};
let output = wrapped_ok.run(
serde_json::to_vec(&input).expect("Could not convert input to Vec"),
test_context(),
);
assert_eq!(
output.is_err(),
false,
"Handler threw an unexpected error: {}",
output.err().unwrap()
);
let output_obj: Output = serde_json::from_slice(&output.ok().unwrap()).expect("Could not serialize output");
assert_eq!(
output_obj.msg,
"hello".to_owned(),
"Unexpected output message: {}",
output_obj.msg
);
}
#[test]
fn runtime_captures_error() {
let handler_ok = |e: Input, _c: Context| -> Result<Output, HandlerError> {
let _age = e.name.parse::<u8>()?;
Ok(Output {
msg: "hello".to_owned(),
})
};
let mut wrapped_ok = wrap(handler_ok);
let input = Input {
name: "test".to_owned(),
};
let output = wrapped_ok.run(
serde_json::to_vec(&input).expect("Could not convert input to Vec"),
test_context(),
);
assert_eq!(output.is_err(), true, "Handler did not throw an error");
let err = output.err().unwrap();
assert_eq!(
err.error_type(),
"std::num::ParseIntError",
"Unexpected error_type: {}",
err.error_type()
);
}
}