Merge pull request #60 from 0xProject/error-decorator

Add initial error handling decorator implementation

1 files changed, 35 insertions, 0 deletions

diff --git a/src/utils/decorators.ts b/src/utils/decorators.ts
new file mode 100644
index 000000000..a25f2cff5
--- /dev/null
+++ b/src/utils/decorators.ts
@@ -0,0 +1,35 @@
+import * as _ from 'lodash';
+import {constants} from './constants';
+import {AsyncMethod, ZeroExError} from '../types';
+
+export const decorators = {
+    /**
+     * Source: https://stackoverflow.com/a/29837695/3546986
+     */
+    contractCallErrorHandler(target: object,
+                             key: string|symbol,
+                             descriptor: TypedPropertyDescriptor<AsyncMethod>,
+    ): TypedPropertyDescriptor<AsyncMethod> {
+        const originalMethod = (descriptor.value as AsyncMethod);
+
+        // Do not use arrow syntax here. Use a function expression in
+        // order to use the correct value of `this` in this method
+        // tslint:disable-next-line:only-arrow-functions
+        descriptor.value =  async function(...args: any[]) {
+            try {
+                const result = await originalMethod.apply(this, args);
+                return result;
+            } catch (error) {
+                if (_.includes(error.message, constants.INVALID_JUMP_PATTERN)) {
+                    throw new Error(ZeroExError.INVALID_JUMP);
+                }
+                if (_.includes(error.message, constants.OUT_OF_GAS_PATTERN)) {
+                    throw new Error(ZeroExError.OUT_OF_GAS);
+                }
+                throw error;
+            }
+        };
+
+        return descriptor;
+    },
+};