feat: add warning function

Signed-off-by: andycall <dongtiangche@outlook.com>

packages/rax/src/warning.js

@@ -0,0 +1,37 @@
+let warning = () => {};
+
+if (process.env.NODE_ENV !== 'production') {
+  warning = (condition, format, ...args) => {
+    if (format === undefined) {
+      throw new Error(
+        '`warningWithoutStack(condition, format, ...args)` requires a warning ' +
+        'message argument',
+      );
+    }
+    if (args.length > 8) {
+      // Check before the condition to catch violations early.
+      throw new Error(
+        'warningWithoutStack() currently supports at most 8 arguments.',
+      );
+    }
+    if (condition) {
+      return;
+    }
+    if (typeof console !== 'undefined') {
+      const argsWithFormat = args.map(item => '' + item);
+      argsWithFormat.unshift('Warning: ' + format);
+
+      Function.prototype.apply.call(console.error, console, argsWithFormat);
+    }
+    try {
+      // This error was thrown as a convenience so that you can use this stack
+      // to find the callsite that caused this warning to fire.
+      let argIndex = 0;
+      const message =
+        'Warning: ' + format.replace(/%s/g, () => args[argIndex++]);
+      throw new Error(message);
+    } catch (x) {}
+  };
+}
+
+export default warning;