planning

node_modules/@react-dnd/invariant/src/index.ts

@@ -0,0 +1,39 @@
+/**
+ * Use invariant() to assert state which your program assumes to be true.
+ *
+ * Provide sprintf-style format (only %s is supported) and arguments
+ * to provide information about what broke and what you were
+ * expecting.
+ *
+ * The invariant message will be stripped in production, but the invariant
+ * will remain to ensure logic does not differ in production.
+ */
+
+export function invariant(condition: any, format: string, ...args: any[]) {
+  if (process.env.NODE_ENV !== 'production') {
+    if (format === undefined) {
+      throw new Error('invariant requires an error message argument');
+    }
+  }
+
+  if (!condition) {
+    let error;
+    if (format === undefined) {
+      error = new Error(
+        'Minified exception occurred; use the non-minified dev environment ' +
+          'for the full error message and additional helpful warnings.'
+      );
+    } else {
+      let argIndex = 0;
+      error = new Error(
+        format.replace(/%s/g, function() {
+          return args[argIndex++];
+        })
+      );
+      error.name = 'Invariant Violation';
+    }
+
+    (error as any).framesToPop = 1; // we don't care about invariant's own frame
+    throw error;
+  }
+}