serde_trim:: serde deserialize_with string trim

Support trim

• String
• Vec<String>
• Option<String>

how to use

fn main() {
    #[derive(Deserialize)]
    struct Foo {
        #[serde(deserialize_with = "string_trim")]
        name: String,
    }
    let json = r#"{"name":" "}"#;
    let foo = serde_json::from_str::<Foo>(json).unwrap();
    assert_eq!(foo.name, "");

    #[derive(Deserialize)]
    struct OptionFoo {
        #[serde(deserialize_with = "option_string_trim")]
        name: Option<String>,
    }
    let json = r#"{"name":" "}"#;
    let foo = serde_json::from_str::<OptionFoo>(json).unwrap();
    assert_eq!(foo.name, None);

    #[derive(Deserialize)]
    struct OptionBar {
        #[serde(default, deserialize_with = "option_string_trim")]
        name: Option<String>,
        addr: String,
    }
    let json = r#"{"addr":"ABC"}"#;
    let foo = serde_json::from_str::<OptionBar>(json).unwrap();
    assert_eq!(foo.name, None);
    assert_eq!(foo.addr, "ABC");

    #[derive(Deserialize)]
    struct VecFoo {
        #[serde(deserialize_with = "vec_string_trim")]
        name: Vec<String>,
    }
    let json = r#"{"name":["   ","foo","b ar","hello ","  rust"]}"#;
    let foo = serde_json::from_str::<VecFoo>(json).unwrap();
    assert_eq!(foo.name, vec!["", "foo", "b ar", "hello", "rust"]);
}