Implement multiple entry points for igniteui-angular (#16326)

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Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: kdinev <[email protected]>
Co-authored-by: Konstantin Dinev <[email protected]>
Co-authored-by: Konstantin Dinev <[email protected]>
Co-authored-by: wnvko <[email protected]>
Co-authored-by: Galina Edinakova <[email protected]>
Co-authored-by: damyanpetev <[email protected]>
Co-authored-by: Radoslav Karaivanov <[email protected]>

Author: 6 people

CHANGELOG.md

@@ -3,6 +3,50 @@
 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.
+- Grid-specific entry points for tree-shakable imports:
+  - `igniteui-angular/grids/core` - Shared grid infrastructure (columns, toolbar, filtering, sorting, etc.)
+  - `igniteui-angular/grids/grid` - Standard grid component (`IgxGridComponent`)
+  - `igniteui-angular/grids/tree-grid` - Tree grid component (`IgxTreeGridComponent`)
+  - `igniteui-angular/grids/hierarchical-grid` - Hierarchical grid component (`IgxHierarchicalGridComponent`, `IgxRowIslandComponent`)
+  - `igniteui-angular/grids/pivot-grid` - Pivot grid component (`IgxPivotGridComponent`, `IgxPivotDataSelectorComponent`)
+
+**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`
+
+**Type Renames (to avoid conflicts):**
+- `Direction` → `CarouselAnimationDirection` (in carousel)
+
+**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

README.md

@@ -166,7 +166,7 @@
     },
     "igniteui-angular": {
       "root": "projects/igniteui-angular",
-      "sourceRoot": "projects/igniteui-angular/src",
+      "sourceRoot": "projects/igniteui-angular",
       "projectType": "library",
       "prefix": "lib",
       "architect": {
@@ -204,7 +204,11 @@
               ]
             },
             "tsConfig": "projects/igniteui-angular/tsconfig.spec.json",
-            "karmaConfig": "projects/igniteui-angular/karma.conf.js"
+            "karmaConfig": "projects/igniteui-angular/karma.conf.js",
+            "exclude": [
+                "migrations",
+                "schematics"
+            ]
           }
         },
         "lint": {
@@ -399,6 +403,7 @@
             "outputPath": "dist/bundle-test",
             "index": "projects/bundle-test/src/index.html",
             "browser": "projects/bundle-test/src/main.ts",
+            "server": "projects/bundle-test/src/main.server.ts",
             "polyfills": [
               "zone.js"
             ],
@@ -414,19 +419,25 @@
                 "node_modules"
               ]
             },
-            "server": "projects/bundle-test/src/main.server.ts",
             "ssr": {
               "entry": "projects/bundle-test/server.ts"
             }
           },
           "configurations": {
             "production": {
+              "statsJson": true,
               "budgets": [
                 {
                   "type": "initial",
                   "maximumWarning": "500kb",
                   "maximumError": "1mb"
                 },
+                {
+                  "type": "bundle",
+                  "name": "grid-component",
+                  "maximumWarning": "500kb",
+                  "maximumError": "1mb"
+                },
                 {
                   "type": "anyComponentStyle",
                   "maximumWarning": "2kb",