Don't generate <?php any more

Removes need for HHI.

This was previously blocked due to being unable to execute Hack code
if there were type errors.

With this, there /may/ be type errors until after the autoload map is
generated.

README.md

@@ -28,8 +28,8 @@ Usage
 
 1. Add an `hh_autoload.json` file (see section below) and optionally remove your configuration from composer.json
 2. `composer require hhvm/hhvm-autoload`
-3. Replace any references to `vendor/autoload.php` with  `vendor/hh_autoload.php`
-4. If you are using PHPUnit, you will need to add `vendor/hh_autoload.php` to your `bootstrap.php`, or to `phpunit.xml` as a `bootstrap` file if you don't already have one. This is because PHPUnit automatically loads `vendor/autoload.php`, but is not aware of `vendor/hh_autoload.php`
+3. Replace any references to `vendor/autoload.php` with  `vendor/hh_autoload.hh`
+4. If you are using PHPUnit, you will need to add `vendor/hh_autoload.hh` to your `bootstrap.php`, or to `phpunit.xml` as a `bootstrap` file if you don't already have one. This is because PHPUnit automatically loads `vendor/autoload.php`, but is not aware of `vendor/hh_autoload.hh`
 5. To re-generate the map, run `vendor/bin/hh-autoload`, `composer dump-autoload`, or any other command that generates the map
 
 Configuration (`hh_autoload.json`)
@@ -47,9 +47,9 @@ This will look for autoloadable definitions in `src/`, and also look in `vendor/
 
 The following settings are optional:
 
- - `"extraFiles": ["file1.php"]` - files that should not be autoloaded, but should be `require()`ed by `vendor/hh_autoload.php`. This should be needed much less frequently than under Composer
- - `"includeVendor": false` - do not include `vendor/` definitions in `vendor/hh_autoload.php`
- - `"autoloadFilesBehavior": "scan"|"exec"` - whether autoload `files` from vendor should be `scan`ned for definitions, or `exec`uted by `vendor/hh_autoload.php` - `scan` is the default, and generally favorable, but `exec` is needed if you have dependencies that need code to be executed on startup. `scan` is sufficient if your dependencies just use `files` because they need to define things that aren't classes, which is usually the case.
+ - `"extraFiles": ["file1.php"]` - files that should not be autoloaded, but should be `require()`ed by `vendor/hh_autoload.hh`. This should be needed much less frequently than under Composer
+ - `"includeVendor": false` - do not include `vendor/` definitions in `vendor/hh_autoload.hh`
+ - `"autoloadFilesBehavior": "scan"|"exec"` - whether autoload `files` from vendor should be `scan`ned for definitions, or `exec`uted by `vendor/hh_autoload.hh` - `scan` is the default, and generally favorable, but `exec` is needed if you have dependencies that need code to be executed on startup. `scan` is sufficient if your dependencies just use `files` because they need to define things that aren't classes, which is usually the case.
  - `"devRoots": [ "path/", ...]` - additional roots to only include in dev mode, not when installed as a dependency.
  - `"relativeAutoloadRoot": false` - do not use a path relative to `__DIR__` for autoloading. Instead, use the path to the folder containing `hh_autoload.json` when building the autoload map.
  - `"failureHandler:" classname<Facebook\AutoloadMap\FailureHandler>` - use the specified class to handle definitions that aren't the Map. Your handler will not be invoked for functions or constants
@@ -121,7 +121,7 @@ How It Works
  - This is used to generate something similar to a classmap, except including other kinds of definitions
  - The map is provided to HHVM with [`HH\autoload_set_paths()`](https://docs.hhvm.com/hack/reference/function/HH.autoload_set_paths/)
 
-The [Composer plugin API](https://getcomposer.org/doc/articles/plugins.md) allows it to re-generate the `vendor/hh_autoload.php` file automatically whenever Composer itself regenerates `vendor/autoload.php`
+The [Composer plugin API](https://getcomposer.org/doc/articles/plugins.md) allows it to re-generate the `vendor/hh_autoload.hh` file automatically whenever Composer itself regenerates `vendor/autoload.php`
 
 Contributing
 ============

bin/hh-autoload

@@ -91,7 +91,7 @@ final class GenerateScript {
       ? ($importer->getConfig()['devFailureHandler'] ?? null)
       : ($importer->getConfig()['failureHandler'] ?? null);
 
-    $file = getcwd().'/vendor/hh_autoload.php';
+    $file = getcwd().'/vendor/hh_autoload.hh';
     (new Writer())
       ->setBuilder($importer)
       ->setRoot(getcwd())

src/ComposerPlugin.php

@@ -79,7 +79,7 @@ public function onPostAutoloadDump(Event $event) {
       ->setRelativeAutoloadRoot($importer->getConfig()['relativeAutoloadRoot'])
       ->setFailureHandler($handler)
       ->setIsDev($event->isDevMode())
-      ->writeToFile($this->vendor.'/hh_autoload.php');
+      ->writeToFile($this->vendor.'/hh_autoload.hh');
   }
 
   private function debugMessage(\HH\string $message) {

src/Writer.php

@@ -163,27 +163,33 @@ function ($sub_map): mixed {
       true,
     );
 
-    $map = \var_export($map, true);
+    $map = \var_export($map, true)
+      |> \str_replace('array (', 'darray[', $$)
+      |> \str_replace(')', ']', $$);
+    $autoload_map_typedef = \var_export(__DIR__.'/AutoloadMap.php', true);
     $code = <<<EOF
-<?php
+<?hh
 
 /// Generated file, do not edit by hand ///
 
 namespace Facebook\AutoloadMap\Generated;
 
-function build_id() {
+require_once($autoload_map_typedef);
+
+function build_id(): string {
   return $build_id;
 }
 
-function root() {
+function root(): string {
   return $root;
 }
 
-function is_dev() {
+function is_dev(): bool {
   return $is_dev;
 }
 
-function map() {
+function map(): \Facebook\AutoloadMap\AutoloadMap {
+  /* HH_IGNORE_ERROR[4110] invalid return type */
   return $map;
 }
 
@@ -203,6 +209,14 @@ function map() {
       $code,
     );
 
+    $legacy_file =
+      \dirname($destination_file).'/'.\basename($destination_file, '.hh').'.php';
+    $relative_file = \basename($destination_file);
+    \file_put_contents(
+      $legacy_file,
+      "<?hh\nrequire_once(__DIR__.'/$relative_file');\n",
+    );
+
     return $this;
   }