new(test): test cases about wrong threshold drop config value

Signed-off-by: Leonardo Di Donato <leodidonato@gmail.com>

test/confs/drops_threshold_neg.yaml

@@ -0,0 +1,12 @@
+syscall_event_drops:
+  threshold: -1
+  actions:
+    - ignore
+  rate: .03333
+  max_burst: 10
+  simulate_drops: true
+
+stdout_output:
+  enabled: true
+
+log_stderr: true

test/confs/drops_threshold_oor.yaml

@@ -0,0 +1,12 @@
+syscall_event_drops:
+  threshold: 1.1
+  actions:
+    - ignore
+  rate: .03333
+  max_burst: 10
+  simulate_drops: true
+
+stdout_output:
+  enabled: true
+
+log_stderr: true

test/falco_tests.yaml

@@ -1236,6 +1236,24 @@ trace_files: !mux
     stderr_contains:
       - "syscall event drop action \"log\" does not make sense with the \"ignore\" action"
 
+  monitor_syscall_drops_threshold_oor:
+    exit_status: 1
+    rules_file:
+      - rules/single_rule.yaml
+    conf_file: confs/drops_threshold_oor.yaml
+    trace_file: trace_files/ping_sendto.scap
+    stderr_contains:
+      - "syscall event drops threshold must be a double in the range"
+
+  monitor_syscall_drops_threshold_neg:
+    exit_status: 1
+    rules_file:
+      - rules/single_rule.yaml
+    conf_file: confs/drops_threshold_neg.yaml
+    trace_file: trace_files/ping_sendto.scap
+    stderr_contains:
+      - "syscall event drops threshold must be a double in the range"
+
   monitor_syscall_drops_log:
     exit_status: 0
     rules_file: