example/hello/src/lib.rs

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

extern crate serde_json;

use serde_derive::{Deserialize, Serialize};
use serde_json::{Error, Value};

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
struct Input {
    #[serde(default = "stranger")]
    name: String,
}

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
struct Output {
    greeting: String,
}

fn stranger() -> String {
    "stranger".to_string()
}

pub fn main(args: Value) -> Result<Value, Error> {
    let input: Input = serde_json::from_value(args)?;
    let output = Output {
        greeting: format!("Hello, {}", input.name),
    };
    serde_json::to_value(output)
}