chore: warn on shadowSupportMode 'any' (#3972)

packages/@lwc/engine-core/src/framework/def.ts

@@ -32,7 +32,7 @@ import {
     resolveCircularModuleDependency,
 } from '../shared/circular-module-dependencies';
 
-import { logError } from '../shared/logger';
+import { logError, logWarn } from '../shared/logger';
 import { instrumentDef } from './runtime-instrumentation';
 import { EmptyObject } from './utils';
 import { getComponentRegisteredTemplate } from './component';
@@ -122,6 +122,7 @@ function createComponentDef(Ctor: LightningElementConstructor): ComponentDef {
 
         if (
             !isUndefined(ctorShadowSupportMode) &&
+            ctorShadowSupportMode !== ShadowSupportMode.Any &&
             ctorShadowSupportMode !== ShadowSupportMode.Default &&
             ctorShadowSupportMode !== ShadowSupportMode.Native
         ) {
@@ -130,6 +131,13 @@ function createComponentDef(Ctor: LightningElementConstructor): ComponentDef {
             );
         }
 
+        // TODO [#3971]: Completely remove shadowSupportMode "any"
+        if (ctorShadowSupportMode === ShadowSupportMode.Any) {
+            logWarn(
+                `Invalid value 'any' for static property shadowSupportMode. 'any' is deprecated and will be removed in a future release--use 'native' instead.`
+            );
+        }
+
         if (
             !isUndefined(ctorRenderMode) &&
             ctorRenderMode !== 'light' &&

packages/@lwc/engine-core/src/framework/vm.ts

@@ -94,6 +94,7 @@ export const enum ShadowMode {
 }
 
 export const enum ShadowSupportMode {
+    Any = 'any',
     Default = 'reset',
     Native = 'native',
 }

packages/@lwc/integration-karma/test/mixed-shadow-mode/LightningElement.shadowSupportMode/index.spec.js

@@ -1,6 +1,8 @@
 import { createElement } from 'lwc';
 import { isNativeShadowRootInstance, isSyntheticShadowRootInstance } from 'test-utils';
 
+import Any from 'x/any';
+import Any2 from 'x/any2';
 import Invalid from 'x/invalid';
 import Valid from 'x/valid';
 import NativeOnly from 'x/native';
@@ -15,7 +17,23 @@ describe('shadowSupportMode static property', () => {
     it('should not throw for valid values', () => {
         expect(() => {
             createElement('x-valid', { is: Valid });
-        }).not.toThrowError();
+        }).not.toLogErrorDev();
+    });
+
+    // TODO [#3971]: Completely remove shadowSupportMode "any"
+    it('should warn for deprecated value "any"', () => {
+        // eslint-disable-next-line jest/valid-expect
+        expect(() => {
+            createElement('x-any', { is: Any });
+        }).toLogWarningDev(/Invalid value 'any' for static property shadowSupportMode/);
+
+        if (process.env.SYNTHETIC_SHADOW_ENABLED && !process.env.MIXED_SHADOW) {
+            let elm;
+            expect(() => {
+                elm = createElement('x-any2', { is: Any2 });
+            }).toLogWarningDev(/Invalid value 'any' for static property shadowSupportMode/);
+            expect(isSyntheticShadowRootInstance(elm.shadowRoot)).toBe(true);
+        }
     });
 });
 

packages/@lwc/integration-karma/test/mixed-shadow-mode/LightningElement.shadowSupportMode/x/any/any.js

@@ -0,0 +1,5 @@
+import { LightningElement } from 'lwc';
+
+export default class extends LightningElement {
+    static shadowSupportMode = 'any';
+}

packages/@lwc/integration-karma/test/mixed-shadow-mode/LightningElement.shadowSupportMode/x/any2/any2.js

@@ -0,0 +1,5 @@
+import { LightningElement } from 'lwc';
+
+export default class extends LightningElement {
+    static shadowSupportMode = 'any';
+}