From b0ea1871513cea7c70196b0ab369b7630e6d1034 Mon Sep 17 00:00:00 2001
From: Kasey White <kwhitemsg@gmail.com>
Date: Thu, 29 Dec 2022 18:20:13 -0500
Subject: [PATCH] better data deserialization errors and test hint now runs
 even being in a sequence

---
 crates/aiken-lang/src/ast.rs       | 49 ++++++++++++++++++++++++------
 crates/uplc/src/machine/error.rs   |  4 +--
 crates/uplc/src/machine/runtime.rs | 25 ++++++++++++---
 3 files changed, 62 insertions(+), 16 deletions(-)

diff --git a/crates/aiken-lang/src/ast.rs b/crates/aiken-lang/src/ast.rs
index 86b559fa..2d59a8c7 100644
--- a/crates/aiken-lang/src/ast.rs
+++ b/crates/aiken-lang/src/ast.rs
@@ -87,16 +87,47 @@ pub type UntypedTypeAlias = TypeAlias<()>;
 
 impl TypedFunction {
     pub fn test_hint(&self) -> Option<(BinOp, Box<TypedExpr>, Box<TypedExpr>)> {
-        match &self.body {
-            TypedExpr::BinOp {
-                name,
-                tipo,
-                left,
-                right,
-                ..
-            } if tipo == &bool() => Some((*name, left.clone(), right.clone())),
-            _ => None,
+        do_test_hint(&self.body)
+    }
+}
+
+pub fn do_test_hint(body: &TypedExpr) -> Option<(BinOp, Box<TypedExpr>, Box<TypedExpr>)> {
+    match body {
+        TypedExpr::BinOp {
+            name,
+            tipo,
+            left,
+            right,
+            ..
+        } if tipo == &bool() => Some((*name, left.clone(), right.clone())),
+        TypedExpr::Sequence { expressions, .. } | TypedExpr::Pipeline { expressions, .. } => {
+            if let Some((binop, left, right)) = do_test_hint(&expressions[expressions.len() - 1]) {
+                let mut new_left_expressions = expressions.clone();
+                new_left_expressions.pop();
+                new_left_expressions.push(*left);
+
+                let mut new_right_expressions = expressions.clone();
+                new_right_expressions.pop();
+                new_right_expressions.push(*right);
+
+                Some((
+                    binop,
+                    TypedExpr::Sequence {
+                        expressions: new_left_expressions,
+                        location: Span::empty(),
+                    }
+                    .into(),
+                    TypedExpr::Sequence {
+                        expressions: new_right_expressions,
+                        location: Span::empty(),
+                    }
+                    .into(),
+                ))
+            } else {
+                None
+            }
         }
+        _ => None,
     }
 }
 
diff --git a/crates/uplc/src/machine/error.rs b/crates/uplc/src/machine/error.rs
index d9de5344..7132db2c 100644
--- a/crates/uplc/src/machine/error.rs
+++ b/crates/uplc/src/machine/error.rs
@@ -44,8 +44,8 @@ pub enum Error {
     UnexpectedEd25519PublicKeyLength(usize),
     #[error("Ed25519S Signature should be 64 bytes but it was {0}")]
     UnexpectedEd25519SignatureLength(usize),
-    #[error("Failed to deserialise PlutusData:\n\n{0:#?}")]
-    DeserialisationError(Value),
+    #[error("Failed to deserialise PlutusData using {0}:\n\n{1:#?}")]
+    DeserialisationError(String, Value),
     #[error("Integer overflow")]
     OverflowError,
 }
diff --git a/crates/uplc/src/machine/runtime.rs b/crates/uplc/src/machine/runtime.rs
index a89a0c2d..b2eb90c2 100644
--- a/crates/uplc/src/machine/runtime.rs
+++ b/crates/uplc/src/machine/runtime.rs
@@ -769,7 +769,10 @@ impl DefaultFunction {
                         )),
                     )))
                 }
-                v => Err(Error::DeserialisationError(v.clone())),
+                v => Err(Error::DeserialisationError(
+                    "UnConstrData".to_string(),
+                    v.clone(),
+                )),
             },
             DefaultFunction::UnMapData => match &args[0] {
                 Value::Con(Constant::Data(PlutusData::Map(m))) => {
@@ -788,7 +791,10 @@ impl DefaultFunction {
                             .collect(),
                     )))
                 }
-                v => Err(Error::DeserialisationError(v.clone())),
+                v => Err(Error::DeserialisationError(
+                    "UnMapData".to_string(),
+                    v.clone(),
+                )),
             },
             DefaultFunction::UnListData => match &args[0] {
                 Value::Con(Constant::Data(PlutusData::Array(l))) => {
@@ -800,7 +806,10 @@ impl DefaultFunction {
                             .collect(),
                     )))
                 }
-                v => Err(Error::DeserialisationError(v.clone())),
+                v => Err(Error::DeserialisationError(
+                    "UnListData".to_string(),
+                    v.clone(),
+                )),
             },
             DefaultFunction::UnIData => match &args[0] {
                 Value::Con(Constant::Data(PlutusData::BigInt(b))) => {
@@ -812,13 +821,19 @@ impl DefaultFunction {
                         unreachable!()
                     }
                 }
-                v => Err(Error::DeserialisationError(v.clone())),
+                v => Err(Error::DeserialisationError(
+                    "UnIData".to_string(),
+                    v.clone(),
+                )),
             },
             DefaultFunction::UnBData => match &args[0] {
                 Value::Con(Constant::Data(PlutusData::BoundedBytes(b))) => {
                     Ok(Value::Con(Constant::ByteString(b.to_vec())))
                 }
-                v => Err(Error::DeserialisationError(v.clone())),
+                v => Err(Error::DeserialisationError(
+                    "UnBData".to_string(),
+                    v.clone(),
+                )),
             },
             DefaultFunction::EqualsData => match (&args[0], &args[1]) {
                 (Value::Con(Constant::Data(d1)), Value::Con(Constant::Data(d2))) => {