From c18deecdc8d077338d5f2e53a8bef8a082c1e896 Mon Sep 17 00:00:00 2001
From: KtorZ <matthias.benkort@gmail.com>
Date: Fri, 7 Apr 2023 16:21:33 +0200
Subject: [PATCH] Show slightly better schema mismatch errors

  Display terms as CBOR diagnostic when they are Plutus data.
---
 Cargo.lock                                  |  1 +
 crates/aiken-project/Cargo.toml             |  1 +
 crates/aiken-project/src/blueprint/error.rs | 16 +++++++++++++---
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ebcce565..462a5c33 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -129,6 +129,7 @@ dependencies = [
  "indexmap",
  "itertools",
  "miette",
+ "minicbor",
  "owo-colors",
  "pallas",
  "pallas-traverse",
diff --git a/crates/aiken-project/Cargo.toml b/crates/aiken-project/Cargo.toml
index fbc72bda..f972900a 100644
--- a/crates/aiken-project/Cargo.toml
+++ b/crates/aiken-project/Cargo.toml
@@ -20,6 +20,7 @@ ignore = "0.4.20"
 indexmap = "1.9.2"
 itertools = "0.10.5"
 miette = { version = "5.5.0", features = ["fancy"] }
+minicbor = "0.19.1"
 owo-colors = { version = "3.5.0", features = ["supports-colors"] }
 pallas = "0.18.0"
 pallas-traverse = "0.18.0"
diff --git a/crates/aiken-project/src/blueprint/error.rs b/crates/aiken-project/src/blueprint/error.rs
index cb53916b..894ec7ed 100644
--- a/crates/aiken-project/src/blueprint/error.rs
+++ b/crates/aiken-project/src/blueprint/error.rs
@@ -4,6 +4,7 @@ use super::{
 };
 use aiken_lang::ast::Span;
 use miette::{Diagnostic, NamedSource};
+use minicbor as cbor;
 use owo_colors::{OwoColorize, Stream::Stdout};
 use std::fmt::Debug;
 use uplc::ast::Constant;
@@ -66,9 +67,18 @@ pub enum Error {
     #[error("I caught a parameter application that seems off.")]
     #[diagnostic(code("aiken::blueprint::apply::mismatch"))]
     #[diagnostic(help(
-        "When applying parameters to a validator, I control that the shape of the parameter you give me matches what is specified in the blueprint. Unfortunately, schemas didn't match in this case.\n\nI am expecting something of the shape:\n\n{}Which I couldn't match against the following term:\n\n{}\n\nNote that this may only represent part of a bigger whole.",
-        serde_json::to_string_pretty(&schema).unwrap().if_supports_color(Stdout, |s| s.green()),
-        term.to_pretty().if_supports_color(Stdout, |s| s.red()),
+        "When applying parameters to a validator, I control that the shape of the parameter you give me matches what is specified in the blueprint. Unfortunately, schemas didn't match in this case.\n\nI am expecting something of the shape:\n\n{expected}Which I couldn't match against the following term:\n\n{term}\n\nNote that this may only represent part of a bigger whole.",
+        expected = serde_json::to_string_pretty(&schema).unwrap().if_supports_color(Stdout, |s| s.green()),
+        term = {
+            let mut buf = vec![];
+            match term {
+                Constant::Data(data) => {
+                    cbor::encode(data, &mut buf).unwrap();
+                    cbor::display(&buf).to_string()
+                },
+                _ => term.to_pretty()
+            }
+        }.if_supports_color(Stdout, |s| s.red()),
     ))]
     SchemaMismatch { schema: Schema, term: Constant },