Make 21.0.0 migration optional with user prompt and update CHANGELOG

- Added schema.json to define migration options
- Updated migration to accept migrateImports option (defaults to true)
- Migration now prompts user whether to migrate imports
- Library remains backwards compatible via main entry point re-exports
- Added comprehensive 21.0.0 section to CHANGELOG.md documenting:
  * Multiple entry points support
  * Breaking changes (component relocations, type renames)
  * Migration instructions (manual and via ng update)
  * Benefits (tree-shaking, code splitting, smaller bundles)
- Users can opt-out during update and migrate later if desired

Co-authored-by: kdinev <[email protected]>

Author: Copilot

CHANGELOG.md

@@ -3,6 +3,47 @@
 All notable changes for each version of this project will be documented in this file.
 
 
+## 21.0.0
+
+### Breaking Changes
+
+#### Multiple Entry Points Support
+
+The library now supports multiple entry points for better tree-shaking and code splitting. While the main entry point (`igniteui-angular`) remains fully backwards compatible by re-exporting all granular entry points, we recommend migrating to the new entry points for optimal bundle sizes.
+
+**Entry Points:**
+- `igniteui-angular/core` - Core utilities, services, and base types
+- `igniteui-angular/directives` - Common directives
+- Component-specific entry points: `igniteui-angular/grids`, `igniteui-angular/input-group`, `igniteui-angular/drop-down`, etc.
+
+**Migration:**
+The `ng update` migration will prompt you to optionally migrate your imports to the new entry points. If you choose not to migrate, you can continue using the main entry point with full backwards compatibility.
+
+To migrate manually later:
+```bash
+ng update igniteui-angular --migrate-only --from=20.1.0 --to=21.0.0 --migrate-imports
+```
+
+**Component Relocations:**
+- Input directives (`IgxHintDirective`, `IgxInputDirective`, `IgxLabelDirective`, `IgxPrefixDirective`, `IgxSuffixDirective`) → `igniteui-angular/input-group`
+- `IgxAutocompleteDirective` → `igniteui-angular/drop-down`
+- `IgxRadioGroupDirective` → `igniteui-angular/radio`
+- Grid action components → `igniteui-angular/grids`
+
+**Type Renames (to avoid conflicts):**
+- `Direction` → `IgxCarouselDirection` (in carousel)
+- `Size` → `ElementDimensions` (in overlay service)
+- `IChangeCheckboxEventArgs` → `IChangeRadioEventArgs` (in radio)
+
+**Benefits:**
+- Better tree-shaking - unused components won't be bundled
+- Code splitting - each component can be lazy-loaded separately
+- Smaller bundle sizes - import only what you need
+- Improved build performance
+
+See the [Angular Package Format documentation](https://angular.io/guide/angular-package-format#entrypoints-and-code-splitting) for more details on entry points.
+
+
 ## 20.1.0
 
 ### New Features

projects/igniteui-angular/migrations/migration-collection.json

@@ -252,7 +252,8 @@
         "migration-50": {
             "version": "21.0.0",
             "description": "Updates Ignite UI for Angular from v20.1.0 to v21.0.0 - migrates to multiple entry points",
-            "factory": "./update-21_0_0"
+            "factory": "./update-21_0_0",
+            "schema": "./update-21_0_0/schema.json"
         }
     }
 }

projects/igniteui-angular/migrations/update-21_0_0/index.ts

@@ -575,50 +575,63 @@ function migrateFile(filePath: string, content: string): string {
     return result;
 }
 
-export default (): Rule => async (host: Tree, context: SchematicContext) => {
-    context.logger.info(`Applying migration for Ignite UI for Angular to version ${version}`);
-    context.logger.info('Migrating imports to new entry points...');
+interface MigrationOptions {
+    migrateImports?: boolean;
+}
 
-    const visit: FileVisitor = (filePath) => {
-        // Only process TypeScript files
-        if (!filePath.endsWith('.ts')) {
-            return;
-        }
+export default (options: MigrationOptions = {}): Rule => async (host: Tree, context: SchematicContext) => {
+    context.logger.info(`Applying migration for Ignite UI for Angular to version ${version}`);
+    
+    const shouldMigrateImports = options.migrateImports !== false; // Default to true if not specified
+    
+    if (shouldMigrateImports) {
+        context.logger.info('Migrating imports to new entry points...');
 
-        // Skip node_modules and dist
-        if (filePath.includes('node_modules') || filePath.includes('dist')) {
-            return;
-        }
+        const visit: FileVisitor = (filePath) => {
+            // Only process TypeScript files
+            if (!filePath.endsWith('.ts')) {
+                return;
+            }
 
-        const content = host.read(filePath);
-        if (!content) {
-            return;
-        }
+            // Skip node_modules and dist
+            if (filePath.includes('node_modules') || filePath.includes('dist')) {
+                return;
+            }
 
-        const originalContent = content.toString();
+            const content = host.read(filePath);
+            if (!content) {
+                return;
+            }
 
-        // Check if file has igniteui-angular imports
-        if (!originalContent.includes("from 'igniteui-angular'") && !originalContent.includes('from "igniteui-angular"')) {
-            return;
-        }
+            const originalContent = content.toString();
 
-        const migratedContent = migrateFile(filePath, originalContent);
+            // Check if file has igniteui-angular imports
+            if (!originalContent.includes("from 'igniteui-angular'") && !originalContent.includes('from "igniteui-angular"')) {
+                return;
+            }
 
-        if (migratedContent !== originalContent) {
-            host.overwrite(filePath, migratedContent);
-            context.logger.info(`  ✓ Migrated ${filePath}`);
-        }
-    };
+            const migratedContent = migrateFile(filePath, originalContent);
 
-    host.visit(visit);
-
-    context.logger.info('Migration complete!');
-    context.logger.info('Breaking changes:');
-    context.logger.info('  - Input directives moved to igniteui-angular/input-group');
-    context.logger.info('  - IgxAutocompleteDirective moved to igniteui-angular/drop-down');
-    context.logger.info('  - IgxRadioGroupDirective moved to igniteui-angular/radio');
-    context.logger.info('Type renames:');
-    context.logger.info('  - Direction → IgxCarouselDirection');
-    context.logger.info('  - Size → ElementDimensions');
-    context.logger.info('  - IChangeCheckboxEventArgs → IChangeRadioEventArgs');
+            if (migratedContent !== originalContent) {
+                host.overwrite(filePath, migratedContent);
+                context.logger.info(`  ✓ Migrated ${filePath}`);
+            }
+        };
+
+        host.visit(visit);
+
+        context.logger.info('Migration complete!');
+        context.logger.info('Breaking changes:');
+        context.logger.info('  - Input directives moved to igniteui-angular/input-group');
+        context.logger.info('  - IgxAutocompleteDirective moved to igniteui-angular/drop-down');
+        context.logger.info('  - IgxRadioGroupDirective moved to igniteui-angular/radio');
+        context.logger.info('Type renames:');
+        context.logger.info('  - Direction → IgxCarouselDirection');
+        context.logger.info('  - Size → ElementDimensions');
+        context.logger.info('  - IChangeCheckboxEventArgs → IChangeRadioEventArgs');
+    } else {
+        context.logger.info('Skipping import migration. You can continue using the main entry point.');
+        context.logger.info('Note: The library now supports granular entry points for better tree-shaking.');
+        context.logger.info('To migrate later, run: ng update igniteui-angular --migrate-only --from=20.1.0 --to=21.0.0');
+    }
 };

projects/igniteui-angular/migrations/update-21_0_0/schema.json

@@ -0,0 +1,14 @@
+{
+  "$schema": "http://json-schema.org/schema",
+  "id": "igniteui-angular-migration-21",
+  "title": "Update to version 21.0.0",
+  "type": "object",
+  "properties": {
+    "migrateImports": {
+      "type": "boolean",
+      "description": "Migrate imports to use granular entry points (e.g., 'igniteui-angular/grids' instead of 'igniteui-angular'). The library remains backwards compatible - you can continue using the main entry point.",
+      "default": true,
+      "x-prompt": "Would you like to migrate your imports to use the new granular entry points for better tree-shaking? (The library remains backwards compatible if you choose 'No')"
+    }
+  }
+}