fix: Custom properties should be available on thrown errors

Author: nzakas

src/object-schema.js

@@ -112,53 +112,22 @@ class MissingDependentKeysError extends Error {
 /**
  * Wrapper error for errors occuring during a merge or validate operation.
  */
-class WrapperError extends Error {
+class WrapperError {
 
     /**
      * Creates a new instance.
      * @param {string} key The object key causing the error. 
      * @param {Error} source The source error. 
      */
     constructor(key, source) {
-        super(`Key "${key}": ` + source.message);
-
-        /**
-         * The original source error.
-         * @type {Error}
-         */
-        this.source = source;
-    }
-
-    /**
-     * The stack from the original error.
-     * @returns {string}
-     */
-    get stack() {
-        return this.source.stack;
-    }
-
-    /**
-     * The line number from the original error.
-     * @returns {number}
-     */
-    get lineNumber() {
-        return this.source.lineNumber;
-    }
-
-    /**
-     * The column number from the original error.
-     * @returns {number}
-     */
-    get columnNumber() {
-        return this.source.columnNumber;
-    }
-
-    /**
-     * The filename from the original error.
-     * @returns {string}
-     */
-    get fileName() {
-        return this.source.fileName;
+        return Object.create(source, {
+            message: {
+                value: `Key "${key}": ` + source.message,
+                configurable: true,
+                writable: true,
+                enumerable: true
+            }
+        });
     }
 }
 

tests/object-schema.js

@@ -130,6 +130,34 @@ describe("ObjectSchema", () => {
 
         });
 
+        it("should throw an error with custom properties when merge() throws an error with custom properties", () => {
+            let schema = new ObjectSchema({
+                foo: {
+                    merge() {
+                        throw {
+                            get message() {
+                                return "Boom!";
+                            },
+                            booya: true
+                        };
+                    },
+                    validate() {}
+                }
+            });
+
+            let errorThrown = false;
+
+            try {
+                schema.merge({ foo: true }, { foo: true });
+            } catch (ex) {
+                errorThrown = true;
+                assert.isTrue(ex.booya);
+            }
+
+            assert.isTrue(errorThrown);
+        
+        });
+
         it("should call the merge() strategy for one key when called", () => {
 
             schema = new ObjectSchema({