From 7d816f54a6df356e14bf0bee1d8a19fe1d2d3c5b Mon Sep 17 00:00:00 2001
From: Alexandre Plateau <lexplt.dev@gmail.com>
Date: Mon, 6 May 2024 19:27:08 +0200
Subject: [PATCH] feat(error): adding proper error messages to str:format when
 fmtlib fails to format

---
 src/arkreactor/Builtins/String.cpp               | 16 +++++++++++++++-
 tests/errors/callable/fmt_arg_not_found.ark      |  1 +
 tests/errors/callable/fmt_arg_not_found.expected |  1 +
 3 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 tests/errors/callable/fmt_arg_not_found.ark
 create mode 100644 tests/errors/callable/fmt_arg_not_found.expected

diff --git a/src/arkreactor/Builtins/String.cpp b/src/arkreactor/Builtins/String.cpp
index d9b37f1cd..ec9dae7a2 100644
--- a/src/arkreactor/Builtins/String.cpp
+++ b/src/arkreactor/Builtins/String.cpp
@@ -3,6 +3,7 @@
 #include <utf8.hpp>
 #include <fmt/args.h>
 #include <fmt/core.h>
+#include <fmt/format.h>
 
 #include <Ark/TypeChecker.hpp>
 #include <Ark/VM/VM.hpp>
@@ -51,7 +52,20 @@ namespace Ark::internal::Builtins::String
                 store.push_back(it->toString(*vm));
         }
 
-        return Value(fmt::vformat(n[0].stringRef(), store));
+        try
+        {
+            return Value(fmt::vformat(n[0].stringRef(), store));
+        }
+        catch (fmt::format_error& e)
+        {
+            throw std::runtime_error(
+                fmt::format("str:format: can not format \"{}\" ({} argument{} provided) because of {}",
+                            n[0].stringRef(),
+                            n.size() - 1,
+                            // if we have more than one argument (not counting the string to format), plural form
+                            n.size() > 2 ? "s" : "",
+                            e.what()));
+        }
     }
 
     /**
diff --git a/tests/errors/callable/fmt_arg_not_found.ark b/tests/errors/callable/fmt_arg_not_found.ark
new file mode 100644
index 000000000..6beb8dbf6
--- /dev/null
+++ b/tests/errors/callable/fmt_arg_not_found.ark
@@ -0,0 +1 @@
+(str:format "Hello {}, I'm {}" "World")
diff --git a/tests/errors/callable/fmt_arg_not_found.expected b/tests/errors/callable/fmt_arg_not_found.expected
new file mode 100644
index 000000000..e736837c1
--- /dev/null
+++ b/tests/errors/callable/fmt_arg_not_found.expected
@@ -0,0 +1 @@
+str:format: can not format "Hello {}, I'm {}" (1 argument provided) because of argument not found