docs: add documentation for NG0401 error (#63947)

PR Close #63947

Author: alan-agius4

adev/src/content/reference/errors/NG0401.md

@@ -0,0 +1,18 @@
+# Missing Platform
+
+Angular requires a platform to be initialized. This error is thrown when `bootstrapApplication` is used on the server without providing a `BootstrapContext`.
+
+When using server-side rendering, `bootstrapApplication` requires a `BootstrapContext` to be passed as an argument.
+
+## Debugging the error
+
+To resolve this error, ensure that your `main.server.ts` file correctly passes a `BootstrapContext` to the `bootstrapApplication` function.
+
+```typescript
+import { bootstrapApplication, BootstrapContext } from '@angular/platform-browser';
+import { App } from './app/app';
+import { config } from './app/app.config.server';
+
+const bootstrap = (context: BootstrapContext) => bootstrapApplication(App, config, context);
+export default bootstrap;
+```

adev/src/content/reference/errors/overview.md

@@ -12,6 +12,7 @@
 | `NG0300`  | [Selector Collision](errors/NG0300)                                                  |
 | `NG0301`  | [Export Not Found](errors/NG0301)                                                    |
 | `NG0302`  | [Pipe Not Found](errors/NG0302)                                                      |
+| `NG0401`  | [Missing platform](errors/NG0401)                                                    |
 | `NG0403`  | [Bootstrapped NgModule doesn't specify which component to initialize](errors/NG0403) |
 | `NG0500`  | [Hydration Node Mismatch](errors/NG0500)                                             |
 | `NG0501`  | [Hydration Missing Siblings](errors/NG0501)                                          |
@@ -30,7 +31,7 @@
 | `NG01203` | [Missing value accessor](errors/NG01203)                                             |
 | `NG02200` | [Missing Iterable Differ](errors/NG02200)                                            |
 | `NG02800` | [JSONP support in HttpClient configuration](errors/NG02800)                          |
-| `NG02802` | [Headers not transferred by HttpTransferCache](errors/NG02802)                      |
+| `NG02802` | [Headers not transferred by HttpTransferCache](errors/NG02802)                       |
 | `NG05000` | [Hydration with unsupported Zone.js instance.](errors/NG05000)                       |
 | `NG05104` | [Root element was not found.](errors/NG05104)                                        |
 

goldens/public-api/core/errors.api.md

@@ -140,7 +140,7 @@ export const enum RuntimeErrorCode {
     // (undocumented)
     PLATFORM_ALREADY_DESTROYED = 404,
     // (undocumented)
-    PLATFORM_NOT_FOUND = 401,
+    PLATFORM_NOT_FOUND = -401,
     // (undocumented)
     PROVIDED_BOTH_ZONE_AND_ZONELESS = 408,
     // (undocumented)

packages/core/src/errors.ts

@@ -66,7 +66,7 @@ export const enum RuntimeErrorCode {
 
   // Bootstrap Errors
   MULTIPLE_PLATFORMS = 400,
-  PLATFORM_NOT_FOUND = 401,
+  PLATFORM_NOT_FOUND = -401,
   MISSING_REQUIRED_INJECTABLE_IN_BOOTSTRAP = 402,
   BOOTSTRAP_COMPONENTS_NOT_FOUND = -403,
   PLATFORM_ALREADY_DESTROYED = 404,