From a99892389efefd9a1ba3f5a79ba0c35d08f6ac0a Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Fri, 15 May 2026 20:20:59 +0000
Subject: [PATCH] test: Add standalone test for mermaid invalid USERNAME
 validation

Added `test/_global/mermaid_invalid_user.sh` to explicitly test the error path in `src/mermaid/install.sh` when an invalid `USERNAME` format is provided. This test script runs the install script directly with a bad username and asserts the script fails with the expected error output.

Co-authored-by: MiguelRodo <23501332+MiguelRodo@users.noreply.github.com>
---
 test/_global/mermaid_invalid_user.sh | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100755 test/_global/mermaid_invalid_user.sh

diff --git a/test/_global/mermaid_invalid_user.sh b/test/_global/mermaid_invalid_user.sh
new file mode 100755
index 0000000..99dd7be
--- /dev/null
+++ b/test/_global/mermaid_invalid_user.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+set -e
+
+# SCRIPT_DIR is the directory of this script
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+INSTALL_SCRIPT="$SCRIPT_DIR/../../src/mermaid/install.sh"
+
+echo "Testing invalid USERNAME..."
+output=$(USERNAME="-invalid" bash "$INSTALL_SCRIPT" 2>&1 || true)
+
+if echo "$output" | grep -q "Error: Invalid USERNAME"; then
+    echo "✅ Success: Caught invalid username"
+    exit 0
+else
+    echo "❌ Fail: Did not catch invalid username"
+    echo "Output was: $output"
+    exit 1
+fi