From fa7cf3c33f17e9d7e518ef09efcb4f423af78ad0 Mon Sep 17 00:00:00 2001
From: jlangch <juerg.lang@ggaweb.ch>
Date: Sat, 30 Mar 2024 15:46:58 +0100
Subject: [PATCH] added support for tracing exceptions in `trace/trace-var`

---
 ChangeLog.md                                  |  1 +
 .../modules/ModuleTracingSection.java         |  2 +-
 .../com/github/jlangch/venice/trace.venice    | 25 ++++++++++++++++---
 3 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 82e65bdae..8a2f2d91e 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -13,6 +13,7 @@ All notable changes to this project will be documented in this file.
 - function `io/file-normalize-utf`
 - thread type support to the function `thread` to allow spawning daemon or user 
   threads
+- support for tracing exceptions in `trace/trace-var`
 
 
 
diff --git a/src/main/java/com/github/jlangch/venice/impl/docgen/cheatsheet/modules/ModuleTracingSection.java b/src/main/java/com/github/jlangch/venice/impl/docgen/cheatsheet/modules/ModuleTracingSection.java
index 69446f6a0..62b544e67 100644
--- a/src/main/java/com/github/jlangch/venice/impl/docgen/cheatsheet/modules/ModuleTracingSection.java
+++ b/src/main/java/com/github/jlangch/venice/impl/docgen/cheatsheet/modules/ModuleTracingSection.java
@@ -45,7 +45,7 @@ public DocSection section() {
         final DocSection trace = new DocSection("Tracing", id());
         all.addSection(trace);
         trace.addItem(diBuilder.getDocItem("trace/trace"));
-        trace.addItem(diBuilder.getDocItem("trace/trace-var"));
+        trace.addItem(diBuilder.getDocItem("trace/trace-var", true, true));
         trace.addItem(diBuilder.getDocItem("trace/untrace-var"));
 
         final DocSection test = new DocSection("Test", id());
diff --git a/src/main/resources/com/github/jlangch/venice/trace.venice b/src/main/resources/com/github/jlangch/venice/trace.venice
index 83f018d36..c6109ee1b 100644
--- a/src/main/resources/com/github/jlangch/venice/trace.venice
+++ b/src/main/resources/com/github/jlangch/venice/trace.venice
@@ -54,9 +54,13 @@
   (let [id (gensym "t")]
     (tracer id (str (trace-indent) (pr-str (cons name args))))
     (binding [*trace-depth* (inc *trace-depth*)]
-      (let [result (apply f args)]
-        (tracer id (str (trace-indent) "=> " (pr-str result)))
-        result))))
+      (try
+        (let [result (apply f args)]
+          (tracer id (str (trace-indent) "=> " (pr-str result)))
+          result)
+        (catch :Exception e
+          (tracer id (str (trace-indent) "=> " (pr-str e)))
+          (throw e))))))
 
 
 (defn
@@ -150,7 +154,7 @@
           (t/trace-var +)
 
           (+ 1 2))
-        """
+        """,
         """
         (do
           (load-module :trace ['trace :as 't])
@@ -163,6 +167,19 @@
           (t/trace-var foo)
           (t/trace-var bar)
 
+          (bar 5))
+        """,
+        """
+        (do
+          (load-module :trace ['trace :as 't])
+
+          (defn foo [x] (/ x 0)) ;; division by zero!
+          (defn bar [x] (foo x))
+
+          (t/trace-var /)
+          (t/trace-var foo)
+          (t/trace-var bar)
+
           (bar 5))
         """ )
      :see-also '(