fix(ivy): support multiple exportAs (#27996)

Allows for multiple, comma-separated `exportAs` names, similarly to `ViewEngine`.

These changes fix FW-708.

PR Close #27996

packages/core/src/render3/definition.ts

@@ -151,7 +151,7 @@ export function defineComponent<T>(componentDefinition: {
    *
    * See: {@link Directive.exportAs}
    */
-  exportAs?: string;
+  exportAs?: string[];
 
   /**
    * Template function use for rendering DOM.
@@ -605,7 +605,7 @@ export const defineDirective = defineComponent as any as<T>(directiveDefinition:
    *
    * See: {@link Directive.exportAs}
    */
-  exportAs?: string;
+  exportAs?: string[];
 }) => never;
 
 /**

packages/core/src/render3/instructions.ts

@@ -1716,7 +1716,11 @@ function saveNameToExportMap(
     index: number, def: DirectiveDef<any>| ComponentDef<any>,
     exportsMap: {[key: string]: number} | null) {
   if (exportsMap) {
-    if (def.exportAs) exportsMap[def.exportAs] = index;
+    if (def.exportAs) {
+      for (let i = 0; i < def.exportAs.length; i++) {
+        exportsMap[def.exportAs[i]] = index;
+      }
+    }
     if ((def as ComponentDef<any>).template) exportsMap[''] = index;
   }
 }

packages/core/src/render3/interfaces/definition.ts

@@ -121,7 +121,7 @@ export interface DirectiveDef<T> extends BaseDef<T> {
   /**
    * Name under which the directive is exported (for use with local references in template)
    */
-  readonly exportAs: string|null;
+  readonly exportAs: string[]|null;
 
   /**
    * Factory function used to create a new directive instance.
@@ -349,4 +349,4 @@ export type PipeTypeList =
 
 // Note: This hack is necessary so we don't erroneously get a circular dependency
 // failure based on types.
-export const unusedValueExportToPlacateAjd = 1;
+export const unusedValueExportToPlacateAjd = 1;