Fix missing stacks in WWW warnings (#17638)

packages/shared/consoleWithStackDev.js

@@ -26,6 +26,8 @@ export function error(format, ...args) {
 }
 
 function printWarning(level, format, args) {
+  // When changing this logic, you might want to also
+  // update consoleWithStackDev.www.js as well.
   if (__DEV__) {
     const hasExistingStack =
       args.length > 0 &&

packages/shared/forks/consoleWithStackDev.www.js

@@ -8,15 +8,43 @@
 // This refers to a WWW module.
 const warningWWW = require('warning');
 
-export function warn() {
-  // TODO: use different level for "warn".
-  const args = Array.prototype.slice.call(arguments);
-  args.unshift(false);
-  warningWWW.apply(null, args);
+export function warn(format, ...args) {
+  if (__DEV__) {
+    printWarning('warn', format, args);
+  }
 }
 
-export function error() {
-  const args = Array.prototype.slice.call(arguments);
-  args.unshift(false);
-  warningWWW.apply(null, args);
+export function error(format, ...args) {
+  if (__DEV__) {
+    printWarning('error', format, args);
+  }
+}
+
+function printWarning(level, format, args) {
+  if (__DEV__) {
+    const hasExistingStack =
+      args.length > 0 &&
+      typeof args[args.length - 1] === 'string' &&
+      args[args.length - 1].indexOf('\n    in') === 0;
+
+    if (!hasExistingStack) {
+      const React = require('react');
+      const ReactSharedInternals =
+        React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED;
+      // Defensive in case this is fired before React is initialized.
+      if (ReactSharedInternals != null) {
+        const ReactDebugCurrentFrame =
+          ReactSharedInternals.ReactDebugCurrentFrame;
+        const stack = ReactDebugCurrentFrame.getStackAddendum();
+        if (stack !== '') {
+          format += '%s';
+          args.push(stack);
+        }
+      }
+    }
+    // TODO: don't ignore level and pass it down somewhere too.
+    args.unshift(format);
+    args.unshift(false);
+    warningWWW.apply(null, args);
+  }
 }