Show trace logs as part of the test output when any.

```
  ┍━ test ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
  │ PASS [mem: 6370, cpu: 2591822] trace_1
  │ ↳ is negative
  │ ↳ is non-negative
  ┕━━━━━━━━━ 1 tests | 1 passed | 0 failed
  ```

crates/cli/src/lib.rs

@@ -171,6 +171,7 @@ fn fmt_test(eval_info: &EvalInfo, max_mem: usize, max_cpu: usize, styled: bool)
         success,
         script,
         spent_budget,
+        logs,
         ..
     } = eval_info;
 
@@ -178,17 +179,38 @@ fn fmt_test(eval_info: &EvalInfo, max_mem: usize, max_cpu: usize, styled: bool)
     let mem_pad = pretty::pad_left(mem.to_string(), max_mem, " ");
     let cpu_pad = pretty::pad_left(cpu.to_string(), max_cpu, " ");
 
-    format!(
+    let test = format!(
-        "{} [mem: {}, cpu: {}] {}",
+        "{status} [mem: {mem_unit}, cpu: {cpu_unit}] {module}",
-        if *success {
+        status = if *success {
             pretty::style_if(styled, "PASS".to_string(), |s| s.bold().green().to_string())
         } else {
             pretty::style_if(styled, "FAIL".to_string(), |s| s.bold().red().to_string())
         },
-        pretty::style_if(styled, mem_pad, |s| s.bright_white().to_string()),
+        mem_unit = pretty::style_if(styled, mem_pad, |s| s.bright_white().to_string()),
-        pretty::style_if(styled, cpu_pad, |s| s.bright_white().to_string()),
+        cpu_unit = pretty::style_if(styled, cpu_pad, |s| s.bright_white().to_string()),
-        pretty::style_if(styled, script.name.clone(), |s| s.bright_blue().to_string()),
+        module = pretty::style_if(styled, script.name.clone(), |s| s.bright_blue().to_string()),
+    );
+
+    let logs = if logs.is_empty() {
+        String::new()
+    } else {
+        logs.iter()
+            .map(|line| {
+                format!(
+                    "{arrow} {styled_line}",
+                    arrow = "↳".bright_yellow(),
+                    styled_line = line.bright_black()
                 )
+            })
+            .collect::<Vec<_>>()
+            .join("\n")
+    };
+
+    if logs.is_empty() {
+        test
+    } else {
+        [test, logs].join("\n")
+    }
 }
 
 fn fmt_test_summary(tests: &Vec<&EvalInfo>, styled: bool) -> String {

crates/project/src/lib.rs

@@ -714,23 +714,25 @@ where
             }
 
             match script.program.eval(initial_budget) {
-                (Ok(result), remaining_budget, _) => {
+                (Ok(result), remaining_budget, logs) => {
                     let eval_info = EvalInfo {
                         success: result != Term::Error
                             && result != Term::Constant(Constant::Bool(false)),
                         script,
                         spent_budget: initial_budget - remaining_budget,
                         output: Some(result),
+                        logs,
                     };
 
                     results.push(eval_info);
                 }
-                (Err(..), remaining_budget, _) => {
+                (Err(..), remaining_budget, logs) => {
                     let eval_info = EvalInfo {
                         success: false,
                         script,
                         spent_budget: initial_budget - remaining_budget,
                         output: None,
+                        logs,
                     };
 
                     results.push(eval_info);

crates/project/src/script.rs

@@ -43,4 +43,5 @@ pub struct EvalInfo {
     pub script: Script,
     pub spent_budget: ExBudget,
     pub output: Option<Term<NamedDeBruijn>>,
+    pub logs: Vec<String>,
 }

examples/acceptance_tests/032/lib/test.ak

@@ -1,5 +1,14 @@
 use aiken/builtin
 
-test trace_1() {
+fn is_negative(i : Int) -> Bool {
-  builtin.trace("foo", True)
+  if i < 0 {
+    builtin.trace("is negative", True)
+  } else {
+    builtin.trace("is non-negative", False)
+  }
+}
+
+
+test trace_1() {
+  is_negative(-14) && !is_negative(42)
 }