From 3e2d616da6683f2e04d2a16c4568488df9fe3176 Mon Sep 17 00:00:00 2001
From: Ivan Goncharov <ivan.goncharov.ua@gmail.com>
Date: Tue, 30 Jul 2019 13:26:53 +0300
Subject: [PATCH] invariant: improve code that babel outputs

---
 resources/inline-invariant.js | 8 +++-----
 src/jsutils/invariant.js      | 6 +++---
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/resources/inline-invariant.js b/resources/inline-invariant.js
index c2d3a9cdd5..d0a6517985 100644
--- a/resources/inline-invariant.js
+++ b/resources/inline-invariant.js
@@ -15,9 +15,7 @@
  */
 module.exports = function inlineInvariant(context) {
   const replaceTemplate = context.template(`
-    if (!%%cond%%) {
-      invariant(0, %%args%%);
-    }
+    (%%cond%%) || invariant(0, %%args%%)
   `);
 
   return {
@@ -39,9 +37,9 @@ module.exports = function inlineInvariant(context) {
 
 function isAppropriateInvariantCall(node, parent) {
   return (
+    parent.type === 'ExpressionStatement' &&
     node.callee.type === 'Identifier' &&
     node.callee.name === 'invariant' &&
-    node.arguments.length > 0 &&
-    parent.type === 'ExpressionStatement'
+    node.arguments.length > 0
   );
 }
diff --git a/src/jsutils/invariant.js b/src/jsutils/invariant.js
index 083c6b0997..31aacd5a6a 100644
--- a/src/jsutils/invariant.js
+++ b/src/jsutils/invariant.js
@@ -1,9 +1,9 @@
 // @flow strict
 
-export default function invariant(condition: mixed, message: string) {
+/* istanbul ignore file */
+export default function invariant(condition: mixed, message?: string): void {
   const booleanCondition = Boolean(condition);
-  /* istanbul ignore else */
   if (!booleanCondition) {
-    throw new Error(message);
+    throw new Error(message || 'Unexpected invariant triggered');
   }
 }