chore: add builder errors

src/errors.rs

@@ -45,7 +45,7 @@ pub enum MpesaError {
     EncryptionError(#[from] openssl::error::ErrorStack),
     #[error("{0}")]
     Message(&'static str),
-    #[error("An error has occurred while building the request")]
+    #[error("An error has occurred while building the request: {0}")]
     BuilderError(BuilderError),
 }
 
@@ -68,9 +68,9 @@ impl fmt::Display for ApiError {
 
 #[derive(Debug, Error)]
 pub enum BuilderError {
-    #[error("Field {0} is required")]
+    #[error("Field [{0}] is required")]
     UninitializedField(&'static str),
-    #[error("Field {0} is invalid")]
+    #[error("Field [{0}] is invalid")]
     ValidationError(String),
 }
 
@@ -80,8 +80,14 @@ impl From<String> for BuilderError {
     }
 }
 
-impl From<derive_builder::UninitializedFieldError> for BuilderError {
+impl From<derive_builder::UninitializedFieldError> for MpesaError {
     fn from(e: derive_builder::UninitializedFieldError) -> Self {
-        Self::UninitializedField(e.field_name())
+        Self::BuilderError(BuilderError::UninitializedField(e.field_name()))
+    }
+}
+
+impl From<url::ParseError> for MpesaError {
+    fn from(e: url::ParseError) -> Self {
+        Self::BuilderError(BuilderError::ValidationError(e.to_string()))
     }
 }

src/services/express_request.rs

@@ -1,7 +1,7 @@
 use crate::client::{Mpesa, MpesaResult};
 use crate::constants::CommandId;
 use crate::environment::ApiEnvironment;
-use crate::errors::{BuilderError, MpesaError};
+use crate::errors::MpesaError;
 use chrono::prelude::Local;
 use derive_builder::Builder;
 use openssl::base64;
@@ -37,7 +37,7 @@ pub struct MpesaExpressRequestResponse {
 }
 
 #[derive(Builder, Debug, Clone)]
-#[builder(build_fn(error = "BuilderError"))]
+#[builder(build_fn(error = "MpesaError"))]
 pub struct MpesaExpress<'mpesa, Env: ApiEnvironment> {
     #[builder(pattern = "immutable")]
     client: &'mpesa Mpesa<Env>,

src/services/transaction_reversal.rs

@@ -7,8 +7,8 @@ use crate::ApiEnvironment;
 use crate::CommandId;
 use crate::IdentifierTypes;
 use crate::Mpesa;
+use crate::MpesaError;
 use crate::MpesaResult;
-use crate::{BuilderError, MpesaError};
 
 #[derive(Debug, Serialize)]
 #[serde(rename_all = "PascalCase")]
@@ -46,7 +46,7 @@ pub struct TransactionReversalResponse {
 }
 
 #[derive(Builder, Debug)]
-#[builder(build_fn(error = "BuilderError"))]
+#[builder(build_fn(error = "MpesaError"))]
 pub struct TransactionReversal<'mpesa, Env: ApiEnvironment> {
     #[builder(pattern = "immutable")]
     client: &'mpesa Mpesa<Env>,

tests/mpesa-rust/transaction_reversal_test.rs

@@ -71,7 +71,10 @@ async fn transaction_reversal_fails_if_no_transaction_id_is_provided() {
         .build()
         .unwrap_err();
 
-    assert_eq!(err.to_string(), "Field transaction_id is required");
+    assert_eq!(
+        err.to_string(),
+        "An error has occurred while building the request: Field [transaction_id] is required"
+    );
 }
 
 #[tokio::test]
@@ -88,7 +91,7 @@ async fn transaction_reversal_fails_if_no_amount_is_provided() {
         .expect(0)
         .mount(&server)
         .await;
-    if let Err(e) = client
+    let err = client
         .transaction_reversal()
         .initiator("testapi496")
         .try_result_url("https://testdomain.com/ok")
@@ -98,17 +101,9 @@ async fn transaction_reversal_fails_if_no_amount_is_provided() {
         .transaction_id("OEI2AK4Q16")
         .receiver_party("600111")
         .build()
-        .unwrap()
-        .send()
-        .await
-    {
-        let MpesaError::Message(msg) = e else {
-            panic!("Expected MpesaError::Message, but found {}", e);
-        };
-        assert_eq!(msg, "amount is required")
-    } else {
-        panic!("Expected error");
-    }
+        .unwrap_err();
+
+    assert_eq!(err.to_string(), "Field amount is required");
 }
 
 #[tokio::test]