Refactor error handling

alan-turing-institute · Sep 6, 2024 · 62f9db9 · 62f9db9
1 parent ac352c8
commit 62f9db9
Show file tree

Hide file tree

Showing 3 changed files with 22 additions and 4 deletions.
diff --git a/trustchain-api/src/api.rs b/trustchain-api/src/api.rs
@@ -311,12 +311,18 @@ pub trait TrustchainDataAPI {
         let expected_hash = credential
             .credential_subject
             .to_single()
-            .unwrap() // TODO: handle error with ?
+            .ok_or(DataCredentialError::ManyCredentialSubject(
+                credential.credential_subject.clone(),
+            ))?
             .property_set
             .as_ref()
-            .unwrap() // TODO: handle error with ?
+            .ok_or(DataCredentialError::MissingAttribute(
+                "property_set".to_string(),
+            ))?
             .get(DATA_ATTRIBUTE)
-            .unwrap() // TODO: handle error with ?
+            .ok_or(DataCredentialError::MissingAttribute(
+                DATA_ATTRIBUTE.to_string(),
+            ))?
             .as_str()
             .expect("dataset attribute is a str");
 

diff --git a/trustchain-cli/src/bin/main.rs b/trustchain-cli/src/bin/main.rs
@@ -362,6 +362,12 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
                         Err(DataCredentialError::MismatchedHashDigests(_, _)) => {
                             println!("Digest... ❌ (mismatched data hash digests)");
                         }
+                        Err(DataCredentialError::MissingAttribute(att)) => {
+                            println!("Invalid credential... ❌ (missing attribute: \"{att}\")");
+                        }
+                        Err(DataCredentialError::ManyCredentialSubject(subjects)) => {
+                            println!("Invalid credential... ❌ (only one subject permitted, multiple subjects found: {subjects:?})");
+                        }
                         Ok(_) => {
                             println!("Proof.... ✅");
                             println!("Issuer... ✅");

diff --git a/trustchain-core/src/vc.rs b/trustchain-core/src/vc.rs
@@ -1,6 +1,6 @@
 //! Verifiable credential functionality for Trustchain.
 use crate::verifier::VerifierError;
-use ssi::vc::VerificationResult;
+use ssi::vc::{CredentialSubject, OneOrMany, VerificationResult};
 use thiserror::Error;
 
 /// An error relating to verifiable credentials and presentations.
@@ -35,6 +35,12 @@ pub enum DataCredentialError {
     /// Hash digests do not match.
     #[error("Hash digests do not match. Expected: {0}. Actual: {1}.")]
     MismatchedHashDigests(String, String),
+    /// Multiple credential subjects
+    #[error("Multiple credential subjects: {0:?}")]
+    ManyCredentialSubject(OneOrMany<CredentialSubject>),
+    /// Missing attribute
+    #[error("Missing attribute: {0}")]
+    MissingAttribute(String),
 }
 
 impl From<CredentialError> for DataCredentialError {