Turn KeyDecodingError enum into struct with source err as trait object

Signed-off-by: Patrik Stas <patrik.stas@absa.africa>

did_core/did_doc/src/schema/types/jsonwebkey.rs

@@ -1,9 +1,9 @@
 use std::{
     collections::HashMap,
+    error::Error,
     fmt::{self, Display, Formatter},
     str::FromStr,
 };
-use std::error::Error;
 
 use serde::{Deserialize, Serialize};
 use serde_json::Value;

did_core/did_doc/src/schema/verification_method/error.rs

@@ -1,48 +1,92 @@
+use std::{
+    error::Error,
+    fmt,
+    fmt::{Display, Formatter},
+};
+
 use thiserror::Error;
-use crate::schema::types::jsonwebkey::JsonWebKeyError;
 
-use crate::schema::types::multibase::MultibaseWrapperError;
+use crate::schema::types::{jsonwebkey::JsonWebKeyError, multibase::MultibaseWrapperError};
 
 #[derive(Debug, Error)]
-pub enum KeyDecodingError {
-    #[error("Json decoding error: ${0}")]
-    JsonError(serde_json::Error),
-    #[error("Pem decoding error: ${0}")]
-    PemError(pem::PemError),
-    #[error("Unsupported key error: ${0}")]
-    UnsupportedPublicKeyField(&'static str),
-    #[error("Base 58 decoding error: ${0}")]
-    Base58DecodeError(bs58::decode::Error),
-    #[error("Base 64 decoding error: ${0}")]
-    Base64DecodeError(base64::DecodeError),
-    #[error("Hex decoding error: ${0}")]
-    HexDecodeError(hex::FromHexError),
-    #[error("Jwk decoding error: ${0}")]
-    JwkDecodeError(JsonWebKeyError),
-    #[error("Multibase decoding error ${0}")]
-    MultibaseError(MultibaseWrapperError),
+pub struct KeyDecodingError {
+    reason: &'static str,
+    #[source]
+    source: Option<Box<dyn Error + Sync + Send>>,
+}
+
+impl KeyDecodingError {
+    pub fn new(reason: &'static str) -> Self {
+        KeyDecodingError {
+            reason,
+            source: None,
+        }
+    }
+}
+
+impl Display for KeyDecodingError {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        match &self.source {
+            Some(source) => write!(
+                f,
+                "KeyDecodingError, reason: {}, source: {}",
+                self.reason, source
+            ),
+            None => write!(f, "KeyDecodingError, reason: {}", self.reason),
+        }
+    }
 }
 
 impl From<pem::PemError> for KeyDecodingError {
     fn from(error: pem::PemError) -> Self {
-        KeyDecodingError::PemError(error)
+        KeyDecodingError {
+            reason: "Failed to decode PEM",
+            source: Some(Box::new(error)),
+        }
     }
 }
 
 impl From<bs58::decode::Error> for KeyDecodingError {
     fn from(error: bs58::decode::Error) -> Self {
-        KeyDecodingError::Base58DecodeError(error)
+        KeyDecodingError {
+            reason: "Failed to decode base58",
+            source: Some(Box::new(error)),
+        }
     }
 }
 
 impl From<base64::DecodeError> for KeyDecodingError {
     fn from(error: base64::DecodeError) -> Self {
-        KeyDecodingError::Base64DecodeError(error)
+        KeyDecodingError {
+            reason: "Failed to decode base64",
+            source: Some(Box::new(error)),
+        }
     }
 }
 
 impl From<hex::FromHexError> for KeyDecodingError {
     fn from(error: hex::FromHexError) -> Self {
-        KeyDecodingError::HexDecodeError(error)
+        KeyDecodingError {
+            reason: "Failed to decode hex value",
+            source: Some(Box::new(error)),
+        }
+    }
+}
+
+impl From<MultibaseWrapperError> for KeyDecodingError {
+    fn from(error: MultibaseWrapperError) -> Self {
+        KeyDecodingError {
+            reason: "Failed to decode multibase value",
+            source: Some(Box::new(error)),
+        }
+    }
+}
+
+impl From<JsonWebKeyError> for KeyDecodingError {
+    fn from(error: JsonWebKeyError) -> Self {
+        KeyDecodingError {
+            reason: "Failed to decode JWK",
+            source: Some(Box::new(error)),
+        }
     }
 }

did_core/did_doc/src/schema/verification_method/public_key.rs

@@ -34,13 +34,10 @@ impl PublicKeyField {
             PublicKeyField::Multibase {
                 public_key_multibase,
             } => {
-                let multibase = Multibase::from_str(public_key_multibase)
-                    .map_err(KeyDecodingError::MultibaseError)?;
+                let multibase = Multibase::from_str(public_key_multibase)?;
                 Ok(multibase.as_ref().to_vec())
             }
-            PublicKeyField::Jwk { public_key_jwk } => Ok(public_key_jwk
-                .to_vec()
-                .map_err(KeyDecodingError::JwkDecodeError)?),
+            PublicKeyField::Jwk { public_key_jwk } => Ok(public_key_jwk.to_vec()?),
             PublicKeyField::Base58 { public_key_base58 } => {
                 Ok(bs58::decode(public_key_base58).into_vec()?)
             }
@@ -51,9 +48,9 @@ impl PublicKeyField {
             PublicKeyField::Pem { public_key_pem } => {
                 Ok(pem::parse(public_key_pem.as_bytes())?.contents().to_vec())
             }
-            PublicKeyField::Pgp { public_key_pgp: _ } => {
-                Err(KeyDecodingError::UnsupportedPublicKeyField("publicKeyPgp"))
-            }
+            PublicKeyField::Pgp { public_key_pgp: _ } => Err(KeyDecodingError::new(
+                "PGP public key decoding not supported",
+            )),
         }
     }
 
@@ -65,6 +62,8 @@ impl PublicKeyField {
 
 #[cfg(test)]
 mod tests {
+    use std::error::Error;
+
     use super::*;
 
     static PUBLIC_KEY_MULTIBASE: &str = "z6LSbysY2xFMRpGMhb7tFTLMpeuPRaqaWM1yECx2AtzE3KCc";
@@ -124,12 +123,13 @@ mod tests {
         let public_key_field = PublicKeyField::Base58 {
             public_key_base58: "abcdefghijkl".to_string(),
         };
-        let err = public_key_field.key_decoded().unwrap_err();
-        assert!(
-            matches!(err, KeyDecodingError::Base58DecodeError(_)),
-            "Expected Base58DecodeError, got {:?}",
-            err
-        );
+        let err = public_key_field.key_decoded().expect_err("Expected error");
+        println!("Error: {}", err);
+        assert!(err
+            .source()
+            .expect("Error was expected to has source set up.")
+            .is::<bs58::decode::Error>());
+        assert!(err.to_string().contains("Failed to decode base58"));
     }
 
     #[test]
@@ -138,10 +138,11 @@ mod tests {
             public_key_pem: "abcdefghijkl".to_string(),
         };
         let err = public_key_field.key_decoded().unwrap_err();
-        assert!(
-            matches!(err, KeyDecodingError::PemError(_)),
-            "Expected PemError, got {:?}",
-            err
-        );
+        println!("Error: {}", err);
+        assert!(err
+            .source()
+            .expect("Error was expected to has source set up.")
+            .is::<pem::PemError>());
+        assert!(err.to_string().contains("Failed to decode PEM"));
     }
 }