fix: generic helper to map nested prop defs to data

Co-authored-by: Miroslav Bajtoš <mbajtoss@gmail.com>

lib/mongodb.js

@@ -1996,23 +1996,97 @@ function optimizedFindOrCreate(model, filter, data, options, callback) {
 }
 
 /**
- * Convert the decimal properties from string to decimal.
+ * Convert decimal properties from string to decimal.
  * Only supported after mongodb 3.4
  *
  * @param {Object} data The data that might contain a decimal property
  * @param {Object} props The model property definitions
  */
 function convertDecimalProps(data, props) {
-  if (debug.enabled) debug('convertDecimalProps props: ', util.inspect(props));
-  for (const p in props) {
-    const prop = props[p];
-    const isDecimal = data[p] && prop && prop.mongodb &&
-      prop.mongodb.dataType &&
-      prop.mongodb.dataType.toLowerCase() === 'decimal128';
-    if (isDecimal) {
-      data[p] = Decimal128.fromString(data[p]);
-      debug('convertDecimalProps decimal value: ', data[p]);
+  visitAllProperties(data, props, coerceDecimalProperties);
+
+  /**
+ *
+ * @param {*} data Plain Data Object for the matching property definition(s)
+ * @param {*} propDefMap Property definition(s) which include information about property type
+ * @param {*} visitor A callback function which takes a property value and
+ * definition to apply custom property coercion
+ */
+  function visitAllProperties(data, propDefMap, visitor) {
+    if (data === null) return;
+    const props = new Set(Object.keys(data).concat(Object.keys(propDefMap)));
+    for (const p of props) {
+      const value = data[p];
+      const def = propDefMap[p];
+      if (checkNested(def)) {
+        if (Array.isArray(def.type)) {
+          if (value === null || value.length === 0) return;
+          for (const it of value) {
+            visitAllProperties(it, def.type[0].definition.properties, visitor);
+          }
+        } else {
+          visitAllProperties(value, def.type.definition.properties, visitor);
+        }
+      } else {
+        data[p] = visitor(value, def);
+      }
+    }
+  }
+
+  /**
+   *
+   * @param {*} value Property value to coerce into a Decimal128 value
+   * @param {*} def Property definition to check if property is MongoDB
+   * decima type
+   */
+  function coerceDecimalProperties(value, def) {
+    if (checkDecimalProp(def)) {
+      if (Array.isArray(value)) {
+        return value.map(val => Decimal128.fromString(val));
+      } else {
+        return Decimal128.fromString(value);
+      }
+    } else {
+      return value;
     }
   }
+
+  /**
+ * A utility function which checks for nested property definitions
+ *
+ * @param {*} propDefinition Property definition which contains metadata for the
+ * property type
+ */
+  function checkNested(propDefinition) {
+    if (!propDefinition || !propDefinition.type) {
+      return false;
+    }
+    if (Array.isArray(propDefinition.type)) {
+      if (!propDefinition.type[0].definition) {
+        return false;
+      } else {
+        if (propDefinition.type[0].definition.properties) return true;
+      }
+    } else {
+      if (!propDefinition.type.definition) {
+        return false;
+      } else {
+        if (propDefinition.type.definition.properties) return true;
+      }
+    }
+  }
+
+  /**
+ * A utility function which checks if a certain property definition is
+ * decimal128 type
+ * @param {*} propertyDef A property definition containing metadata about property type
+ */
+  function checkDecimalProp(propertyDef) {
+    return propertyDef && propertyDef.mongodb &&
+  propertyDef.mongodb.dataType &&
+  propertyDef.mongodb.dataType.toLowerCase() === 'decimal128';
+  }
+
   return data;
 }
+