safely handle missing parameters

src/vtab/function.rs

@@ -65,8 +65,18 @@ impl BindInfo {
     ///  * `index`: The index of the parameter to get
     ///
     /// returns: The value of the parameter
+    ///
+    /// # Panics
+    /// If requested parameter is out of range for function definition
     pub fn get_parameter(&self, param_index: u64) -> Value {
-        unsafe { Value::from(duckdb_bind_get_parameter(self.ptr, param_index)) }
+        unsafe {
+            let ptr = duckdb_bind_get_parameter(self.ptr, param_index);
+            if ptr.is_null() {
+                panic!("{} is out of range for function definition", param_index);
+            } else {
+                Value::from(ptr)
+            }
+        }
     }
 
     /// Retrieves the named parameter with the given name.
@@ -75,10 +85,15 @@ impl BindInfo {
     /// * `name`: The name of the parameter to get
     ///
     /// returns: The value of the parameter
-    pub fn get_named_parameter(&self, name: &str) -> Value {
+    pub fn get_named_parameter(&self, name: &str) -> Option<Value> {
         unsafe {
             let name = &CString::new(name).unwrap();
-            Value::from(duckdb_bind_get_named_parameter(self.ptr, name.as_ptr()))
+            let ptr = duckdb_bind_get_named_parameter(self.ptr, name.as_ptr());
+            if ptr.is_null() {
+                None
+            } else {
+                Some(Value::from(ptr))
+            }
         }
     }
 

src/vtab/mod.rs

@@ -238,10 +238,6 @@ mod test {
         fn parameters() -> Option<Vec<LogicalType>> {
             Some(vec![LogicalType::new(LogicalTypeId::Varchar)])
         }
-
-        fn named_parameters() -> Option<Vec<(std::string::String, logical_type::LogicalType)>> {
-            Some(vec![("name".to_string(), LogicalType::new(LogicalTypeId::Varchar))])
-        }
     }
 
     struct HelloWithNamedVTab {}
@@ -251,7 +247,8 @@ mod test {
 
         fn bind(bind: &BindInfo, data: *mut HelloBindData) -> Result<(), Box<dyn Error>> {
             bind.add_result_column("column0", LogicalType::new(LogicalTypeId::Varchar));
-            let param = bind.get_named_parameter("name").to_string();
+            let param = bind.get_named_parameter("name").unwrap().to_string();
+            assert!(bind.get_named_parameter("unknown_name").is_none());
             unsafe {
                 (*data).name = CString::new(param).unwrap().into_raw();
             }