planning

node_modules/apollo-utilities/src/util/warnOnce.ts

@@ -0,0 +1,24 @@
+import { isProduction, isTest } from './environment';
+
+const haveWarned = Object.create({});
+
+/**
+ * Print a warning only once in development.
+ * In production no warnings are printed.
+ * In test all warnings are printed.
+ *
+ * @param msg The warning message
+ * @param type warn or error (will call console.warn or console.error)
+ */
+export function warnOnceInDevelopment(msg: string, type = 'warn') {
+  if (!isProduction() && !haveWarned[msg]) {
+    if (!isTest()) {
+      haveWarned[msg] = true;
+    }
+    if (type === 'error') {
+      console.error(msg);
+    } else {
+      console.warn(msg);
+    }
+  }
+}