emberjs · NullVoxPopuli · Feb 24, 2026 · Feb 25, 2026 · Feb 25, 2026 · Feb 25, 2026
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -276,9 +276,7 @@ There are helpers for many of these functions, which will resolve this for you:
 If your tests can't or aren't covered by a helper, one common solution is the use of `DEBUG` flag. Wrapping the debug-only dependent test in a check of this flag will cause that test to not be run in the prod test suite:
 
 ```javascript
-import { DEBUG } from '@glimmer/env';
-
-if (DEBUG) {
+if (import.meta.env?.DEV ?? true) {
   // Development-only test goes here
 }
 ```

diff --git a/package.json b/package.json
@@ -390,4 +390,4 @@
     }
   },
   "packageManager": "pnpm@10.5.0"
-}
+}
diff --git a/packages/@ember/-internals/container/lib/container.ts b/packages/@ember/-internals/container/lib/container.ts
@@ -9,7 +9,7 @@ import type {
 import { setOwner } from '@ember/-internals/owner';
 import { dictionary } from '@ember/-internals/utils';
 import { assert } from '@ember/debug';
-import { DEBUG } from '@glimmer/env';
+
 import type { DebugRegistry } from './registry';
 import type Registry from './registry';
 
@@ -24,7 +24,7 @@ declare const gc: undefined | (() => void);
 
 let leakTracking: LeakTracking;
 let containers: WeakSet<Container>;
-if (DEBUG) {
+if (import.meta.env?.DEV) {
   // requires v8
   // chrome --js-flags="--allow-natives-syntax --expose-gc"
   // node --allow-natives-syntax --expose-gc
@@ -92,7 +92,7 @@ export default class Container {
     this.isDestroyed = false;
     this.isDestroying = false;
 
-    if (DEBUG) {
+    if (import.meta.env?.DEV) {
       this.validationCache = dictionary(options.validationCache || null);
       if (containers !== undefined) {
         containers.add(this);
@@ -232,7 +232,7 @@ export default class Container {
   }
 }
 
-if (DEBUG) {
+if (import.meta.env?.DEV) {
   Container._leakTracking = leakTracking!;
 }
 
@@ -312,13 +312,13 @@ function factoryFor(
     return;
   }
 
-  if (DEBUG && factory && typeof factory._onLookup === 'function') {
+  if (import.meta.env?.DEV && factory && typeof factory._onLookup === 'function') {
     factory._onLookup(fullName);
   }
 
   let manager = new InternalFactoryManager(container, factory, fullName, normalizedName);
 
-  if (DEBUG) {
+  if (import.meta.env?.DEV) {
     manager = wrapManagerInDeprecationProxy(manager);
   }
 
@@ -541,7 +541,7 @@ export class InternalFactoryManager<
     setOwner(props, container.owner!);
     setFactoryFor(props, this);
 
-    if (DEBUG) {
+    if (import.meta.env?.DEV) {
       let lazyInjections;
       let validationCache = this.container.validationCache;
       // Ensure that all lazy injections are valid at instantiation time

diff --git a/packages/@ember/-internals/container/lib/registry.ts b/packages/@ember/-internals/container/lib/registry.ts
@@ -10,7 +10,7 @@ import type {
 import { dictionary, intern } from '@ember/-internals/utils';
 import { assert } from '@ember/debug';
 import type { set } from '@ember/object';
-import { DEBUG } from '@glimmer/env';
+
 import type { ContainerOptions, LazyInjection } from './container';
 import Container from './container';
 
@@ -468,7 +468,7 @@ export declare class DebugRegistry extends Registry {
   validateInjections(injections: Injection[]): void;
 }
 
-if (DEBUG) {
+if (import.meta.env?.DEV) {
   const proto = Registry.prototype as DebugRegistry;
   proto.normalizeInjectionsHash = function (hash: { [key: string]: LazyInjection }) {
     let injections: Injection[] = [];

diff --git a/packages/@ember/-internals/container/tests/container_test.js b/packages/@ember/-internals/container/tests/container_test.js
@@ -1,6 +1,6 @@
 import { getOwner } from '@ember/-internals/owner';
 import Service from '@ember/service';
-import { DEBUG } from '@glimmer/env';
+
 import { Registry } from '..';
 import { factory, moduleFor, AbstractTestCase, runTask } from 'internal-test-helpers';
 
@@ -447,7 +447,7 @@ moduleFor(
     }
 
     ['@test Lazy injection validations are cached'](assert) {
-      if (!DEBUG) {
+      if (!import.meta.env?.DEV) {
         assert.expect(0);
         return;
       }

diff --git a/packages/@ember/-internals/environment/lib/env.ts b/packages/@ember/-internals/environment/lib/env.ts
@@ -1,4 +1,3 @@
-import { DEBUG } from '@glimmer/env';
 import global from './global';
 
 /**
@@ -91,7 +90,7 @@ export const ENV = {
     @default false
     @private
   */
-  _DEBUG_RENDER_TREE: DEBUG,
+  _DEBUG_RENDER_TREE: import.meta.env?.DEV,
 
   /**
    Whether to force all deprecations to be enabled. This is used internally by
@@ -200,7 +199,7 @@ export const ENV = {
     }
   }
 
-  if (DEBUG) {
+  if (import.meta.env?.DEV) {
     ENV._DEBUG_RENDER_TREE = true;
   }
 })(global.EmberENV);

diff --git a/packages/@ember/-internals/glimmer/lib/component-managers/curly.ts b/packages/@ember/-internals/glimmer/lib/component-managers/curly.ts
@@ -9,7 +9,7 @@ import { addChildView, setElementView, setViewElement } from '@ember/-internals/
 import type { Nullable } from '@ember/-internals/utility-types';
 import { assert, debugFreeze } from '@ember/debug';
 import { _instrumentStart } from '@ember/instrumentation';
-import { DEBUG } from '@glimmer/env';
+
 import type {
   Bounds,
   CapturedArguments,
@@ -337,7 +337,7 @@ export default class CurlyComponentManager
       bucket.classRef = args.named.get('class');
     }
 
-    if (DEBUG) {
+    if (import.meta.env?.DEV) {
       processComponentInitializationAssertions(component, props);
     }
 

diff --git a/packages/@ember/-internals/glimmer/lib/component-managers/root.ts b/packages/@ember/-internals/glimmer/lib/component-managers/root.ts
@@ -1,7 +1,7 @@
 import { getFactoryFor } from '@ember/-internals/container';
 import { assert } from '@ember/debug';
 import { _instrumentStart } from '@ember/instrumentation';
-import { DEBUG } from '@glimmer/env';
+
 import type {
   ComponentDefinition,
   Environment,
@@ -57,7 +57,7 @@ class RootComponentManager extends CurlyComponentManager {
       }
     }
 
-    if (DEBUG) {
+    if (import.meta.env?.DEV) {
       processComponentInitializationAssertions(component, {});
     }
 

diff --git a/packages/@ember/-internals/glimmer/lib/component-managers/route-template.ts b/packages/@ember/-internals/glimmer/lib/component-managers/route-template.ts
@@ -14,7 +14,7 @@ import type {
   WithCustomDebugRenderTree,
 } from '@glimmer/interfaces';
 import type { Nullable } from '@ember/-internals/utility-types';
-import { DEBUG } from '@glimmer/env';
+
 import { capabilityFlagsFrom } from '@glimmer/manager';
 import type { Reference } from '@glimmer/reference';
 import { createDebugAliasRef, valueForRef } from '@glimmer/reference';
@@ -61,7 +61,7 @@ class RouteTemplateManager
   ): RouteTemplateInstanceState {
     let self = args.named.get('controller');
 
-    if (DEBUG) {
+    if (import.meta.env?.DEV) {
       self = createDebugAliasRef!('this', self);
     }
 

diff --git a/packages/@ember/-internals/glimmer/lib/component.ts b/packages/@ember/-internals/glimmer/lib/component.ts
@@ -19,7 +19,7 @@ import {
 } from '@ember/-internals/views';
 import { guidFor } from '@ember/-internals/utils';
 import { assert } from '@ember/debug';
-import { DEBUG } from '@glimmer/env';
+
 import type { Environment, Template, TemplateFactory } from '@glimmer/interfaces';
 import { setInternalComponentManager } from '@glimmer/manager';
 import { isUpdatableRef, updateRef } from '@glimmer/reference';
@@ -939,7 +939,12 @@ class Component<S = unknown>
       }
     }
 
-    if (DEBUG && eventDispatcher && this.renderer._isInteractive && this.tagName === '') {
+    if (
+      import.meta.env?.DEV &&
+      eventDispatcher &&
+      this.renderer._isInteractive &&
+      this.tagName === ''
+    ) {
       let eventNames = [];
       let events = eventDispatcher.finalEventNameMapping;
 

diff --git a/packages/@ember/-internals/glimmer/lib/components/link-to.ts b/packages/@ember/-internals/glimmer/lib/components/link-to.ts
@@ -7,7 +7,7 @@ import type EngineInstance from '@ember/engine/instance';
 import { flaggedInstrument } from '@ember/instrumentation';
 import { action } from '@ember/object';
 import { service } from '@ember/service';
-import { DEBUG } from '@glimmer/env';
+
 import type { Maybe } from '@glimmer/interfaces';
 import type { Nullable } from '@ember/-internals/utility-types';
 import { consumeTag, createCache, getValue, tagFor, untrack } from '@glimmer/validator';
@@ -344,7 +344,7 @@ class _LinkTo extends InternalComponent {
     // TODO: can we narrow this down to QP changes only?
     consumeTag(tagFor(routing, 'currentState'));
 
-    if (DEBUG) {
+    if (import.meta.env?.DEV) {
       try {
         return routing.generateURL(route, models, query);
       } catch (e) {

diff --git a/packages/@ember/-internals/glimmer/lib/environment.ts b/packages/@ember/-internals/glimmer/lib/environment.ts
@@ -6,7 +6,7 @@ import { constructStyleDeprecationMessage } from '@ember/-internals/views';
 import { assert, deprecate, warn } from '@ember/debug';
 import type { DeprecationOptions } from '@ember/debug';
 import { schedule, _backburner } from '@ember/runloop';
-import { DEBUG } from '@glimmer/env';
+
 import setGlobalContext from '@glimmer/global-context';
 import type { EnvironmentDelegate } from '@glimmer/runtime';
 import { debug } from '@glimmer/validator';
@@ -57,7 +57,7 @@ setGlobalContext({
   },
 
   assert(test: unknown, msg: string, options?: { id: string }) {
-    if (DEBUG) {
+    if (import.meta.env?.DEV) {
       let id = options?.id;
 
       let override = VM_ASSERTION_OVERRIDES.filter((o) => o.id === id)[0];
@@ -67,7 +67,7 @@ setGlobalContext({
   },
 
   deprecate(msg: string, test: unknown, options: { id: string }) {
-    if (DEBUG) {
+    if (import.meta.env?.DEV) {
       let { id } = options;
 
       if (id === 'argument-less-helper-paren-less-invocation') {
@@ -91,7 +91,7 @@ setGlobalContext({
   },
 });
 
-if (DEBUG) {
+if (import.meta.env?.DEV) {
   debug?.setTrackingTransactionEnv?.({
     debugMessage(obj, keyName) {
       let dirtyString = keyName

diff --git a/packages/@ember/-internals/glimmer/lib/helpers/-in-element-null-check.ts b/packages/@ember/-internals/glimmer/lib/helpers/-in-element-null-check.ts
@@ -1,12 +1,12 @@
 import { assert } from '@ember/debug';
-import { DEBUG } from '@glimmer/env';
+
 import type { CapturedArguments, Helper } from '@glimmer/interfaces';
 import { createComputeRef, valueForRef } from '@glimmer/reference';
 import { internalHelper } from './internal-helper';
 
 let helper: Helper;
 
-if (DEBUG) {
+if (import.meta.env?.DEV) {
   helper = (args: CapturedArguments) => {
     const inner = args.positional[0];
     assert('expected at least one positional arg', inner);

diff --git a/packages/@ember/-internals/glimmer/lib/helpers/-resolve.ts b/packages/@ember/-internals/glimmer/lib/helpers/-resolve.ts
@@ -3,7 +3,7 @@
 */
 import type { FullName, InternalOwner } from '@ember/-internals/owner';
 import { assert } from '@ember/debug';
-import { DEBUG } from '@glimmer/env';
+
 import type { CapturedArguments } from '@glimmer/interfaces';
 import { createConstRef, isConstRef, valueForRef } from '@glimmer/reference';
 import { internalHelper } from './internal-helper';
@@ -30,7 +30,7 @@ export default internalHelper(
       ((s: string): s is FullName => s.split(':').length === 2)(fullName)
     );
 
-    if (DEBUG) {
+    if (import.meta.env?.DEV) {
       let [type, name] = fullName.split(':');
 
       assert(

diff --git a/packages/@ember/-internals/glimmer/lib/renderer.ts b/packages/@ember/-internals/glimmer/lib/renderer.ts
@@ -13,7 +13,7 @@ import {
   isDestroying,
   registerDestructor,
 } from '@glimmer/destroyable';
-import { DEBUG } from '@glimmer/env';
+
 import type {
   Bounds,
   Cursor,
@@ -108,7 +108,7 @@ const NO_OP = () => {};
 // during render. This prevents infinite revalidation type loops from occuring,
 // and ensures that errors are not swallowed by subsequent follow on failures.
 function errorLoopTransaction(fn: () => void) {
-  if (DEBUG) {
+  if (import.meta.env?.DEV) {
     return () => {
       let didError = true;
 

diff --git a/packages/@ember/-internals/glimmer/lib/resolver.ts b/packages/@ember/-internals/glimmer/lib/resolver.ts
@@ -2,7 +2,7 @@ import type { InternalFactory, InternalOwner } from '@ember/-internals/owner';
 import { isFactory } from '@ember/-internals/owner';
 import { assert } from '@ember/debug';
 import { _instrumentStart } from '@ember/instrumentation';
-import { DEBUG } from '@glimmer/env';
+
 import type {
   ClassicResolver,
   HelperDefinitionState,
@@ -111,7 +111,7 @@ export const BUILTIN_HELPERS: Record<string, object> = {
   'unique-id': uniqueId,
 };
 
-if (DEBUG) {
+if (import.meta.env?.DEV) {
   BUILTIN_HELPERS['-disallow-dynamic-resolution'] = disallowDynamicResolution;
 } else {
   // Bug: this may be a quirk of our test setup?
@@ -171,8 +171,8 @@ export default class ResolverImpl implements ClassicResolver<InternalOwner> {
       // than the raw value (`factoryFor(...).class`). This is because injections are already
       // bound in the factoryFor result, including type-based injections
 
-      if (DEBUG) {
-        // In DEBUG we need to only set the associated value once, otherwise
+      if (import.meta.env?.DEV) {
+        // In import.meta.env?.DEV we need to only set the associated value once, otherwise
         // we'll trigger an assertion
         if (!CLASSIC_HELPER_MANAGER_ASSOCIATED.has(factory)) {
           CLASSIC_HELPER_MANAGER_ASSOCIATED.add(factory);

diff --git a/packages/@ember/-internals/glimmer/lib/syntax/mount.ts b/packages/@ember/-internals/glimmer/lib/syntax/mount.ts
@@ -3,7 +3,7 @@
 */
 import type { InternalOwner } from '@ember/-internals/owner';
 import { assert } from '@ember/debug';
-import { DEBUG } from '@glimmer/env';
+
 import type { Nullable } from '@ember/-internals/utility-types';
 import type { CapturedArguments, CurriedComponent } from '@glimmer/interfaces';
 import type { Reference } from '@glimmer/reference';
@@ -64,7 +64,7 @@ export const mountHelper = internalHelper(
       args.positional.length === 1
     );
 
-    if (DEBUG && args.named) {
+    if (import.meta.env?.DEV && args.named) {
       let keys = Object.keys(args.named);
       let extra = keys.filter((k) => k !== 'model');
 

diff --git a/packages/@ember/-internals/glimmer/lib/syntax/outlet.ts b/packages/@ember/-internals/glimmer/lib/syntax/outlet.ts
@@ -1,6 +1,6 @@
 import type { InternalOwner } from '@ember/-internals/owner';
 import { assert } from '@ember/debug';
-import { DEBUG } from '@glimmer/env';
+
 import type {
   CapturedArguments,
   CurriedComponent,
@@ -100,7 +100,7 @@ export const outletHelper = internalHelper(
           if (hasInternalComponentManager(template)) {
             component = template;
           } else {
-            if (DEBUG) {
+            if (import.meta.env?.DEV) {
               // We don't appear to have a standard way or a brand to check, but for the
               // purpose of avoiding obvious user errors, this probably gets you close
               // enough.
@@ -163,7 +163,7 @@ export const outletHelper = internalHelper(
             return model;
           });
 
-          if (DEBUG) {
+          if (import.meta.env?.DEV) {
             named['model'] = createDebugAliasRef!('@model', named['model']);
           }
-Original file line number
+Diff line change
@@ Expand Up / @@ -390,4 +390,4 @@ @@
         }
       },
       "packageManager": "pnpm@10.5.0"
-    }
+    }