Adds an assertion assertEOSErrorIncludesMessage that will assert th…

…e error message for an expected `eosio_assert_message_exception` includes the given description.

src/utils.ts

@@ -141,6 +141,42 @@ export const assertEOSError = async (
 	assert.fail(`Expected ${description} but operation completed successfully.`);
 };
 
+/**
+ * Asserts EOS throws an error and validates the error output name matches the
+ * expected 'eosio_assert_message_exception' and the error message includes `description`
+ * @author Dallas Johnson <github.com/dallasjohnson>
+ * @param operation Operation promise
+ * @param description Output message description
+ */
+export const assertEOSErrorIncludesMessage = async (operation: Promise<any>, message: string) => {
+	const eosErrorName = 'eosio_assert_message_exception';
+	// Execute operation and handle exceptions
+	try {
+		await operation;
+	} catch (error) {
+		let errorMessage = error.json.error.details[0].message;
+		if (error.json && error.json.error && error.json.error.name && errorMessage) {
+			// Compare error and fail if the error doesn't match the expected
+			assert(
+				error.json.error.name === eosErrorName,
+				`Expected ${eosErrorName}, got ${error.json.error.name} instead.`
+			);
+			assert(
+				errorMessage.includes(message),
+				`Expected to include ${message}, got ${errorMessage} instead.`
+			);
+			return;
+		} else {
+			// Fail if error not thrown by EOS
+			assert.fail(
+				`Expected EOS error ${eosErrorName}, but got ${JSON.stringify(error, null, 4)} instead.`
+			);
+		}
+	}
+	// Fail if no exception thrown
+	assert.fail(`Expected ${eosErrorName} but operation completed successfully.`);
+};
+
 /**
  * Asserts operation throws an `eosio_assert_message_exception` error
  * @author Kevin Brown <github.com/thekevinbrown>