From 5ba63620dc478bcdeb0e0feabc9990ac523c7643 Mon Sep 17 00:00:00 2001
From: Philip Top <phlptp@gmail.com>
Date: Wed, 5 Jan 2022 12:36:15 -0800
Subject: [PATCH] fix: update the range error output  (#690)

* update the range error output to be able to be used by more types, and better printouts in some situations.

* style: pre-commit.ci fixes

* add test

* style: pre-commit.ci fixes

* fix the test

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
 include/CLI/Validators.hpp | 10 ++++++----
 tests/AppTest.cpp          | 17 +++++++++++++++++
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/include/CLI/Validators.hpp b/include/CLI/Validators.hpp
index ba3cbe3c..63422cb7 100644
--- a/include/CLI/Validators.hpp
+++ b/include/CLI/Validators.hpp
@@ -480,10 +480,12 @@ class Range : public Validator {
         func_ = [min_val, max_val](std::string &input) {
             T val;
             bool converted = detail::lexical_cast(input, val);
-            if((!converted) || (val < min_val || val > max_val))
-                return std::string("Value ") + input + " not in range " + std::to_string(min_val) + " to " +
-                       std::to_string(max_val);
-
+            if((!converted) || (val < min_val || val > max_val)) {
+                std::stringstream out;
+                out << "Value " << input << " not in range [";
+                out << min_val << " - " << max_val << "]";
+                return out.str();
+            }
             return std::string{};
         };
     }
diff --git a/tests/AppTest.cpp b/tests/AppTest.cpp
index 3e39a7c9..9268925f 100644
--- a/tests/AppTest.cpp
+++ b/tests/AppTest.cpp
@@ -1858,6 +1858,23 @@ TEST_CASE_METHOD(TApp, "RangeDouble", "[app]") {
     run();
 }
 
+TEST_CASE_METHOD(TApp, "NonNegative", "[app]") {
+
+    std::string res;
+    /// Note that this must be a double in Range, too
+    app.add_option("--one", res)->check(CLI::NonNegativeNumber);
+
+    args = {"--one=crazy"};
+    try {
+        // this should throw
+        run();
+        CHECK(false);
+    } catch(const CLI::ValidationError &e) {
+        std::string emess = e.what();
+        CHECK(emess.size() < 70U);
+    }
+}
+
 TEST_CASE_METHOD(TApp, "typeCheck", "[app]") {
 
     /// Note that this must be a double in Range, too