error-reporting.md

Error reporting

• serde_yaml does not support location spans :(

• dtolnay/serde-yaml#201

• https://www.reddit.com/r/learnrust/comments/10s0luu/reporting_multiple_validation_errors_when_reading/

• https://docs.rs/format_serde_error/latest/format_serde_error/

• Storing unknown fields:

  struct Test {
      a: String,
      b: String,
      #[serde(flatten)]
      unk: Map<String, serde_yaml::Value>,
  }

• TryParse

  #[derive(Debug)]
  pub enum TryParse<T> {
      Parsed(T),
      Unparsed(ParsingError),
      NotPresent
  }
  
  impl<'de, T: DeserializeOwned> Deserialize<'de> for TryParse<T> {
      fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
          match Option::<serde_yaml::Value>::deserialize(deserializer)? {
              None => Ok(TryParse::NotPresent),
              Some(value) => match T::deserialize(&value) {
                  Ok(t) => Ok(TryParse::Parsed(t)),
                  Err(e) => Ok(TryParse::Unparsed(ParsingError {
                      value,
                      location: e.location(),
                      error: e.to_string(),
                  })),
              },
          }
      }
  }