Some general cleanup: (#46)

* Some general cleanup:

 - AutoloadMap.hack
  This type should be in sync with HH\autoload_set_paths(),
    but this function has an incorrect hhi.
    I'll make a PR to hhvm, trying to get this fixed.
 - ConfigurationLoader.hack
  Remove an HH_FIXME by making self::fromData accept a
    wider type.
  Use the null constructor on ImmVector instead of a varray.
 - HHClientFallbackHandler.hack
  Require is allowed from inside a function.
    This might have been a parse error in the past.
    disallow_top_level_requires .hhconfig
    option availability suggests that this is now preferred.
 - Merger.hack
  Use a darray typehint where an array typehint was used.
 - Writer.hack
  Prefer inst_meth over calling a varray as a callable.
 - ComposerImporter.hack
  Use darray/varray typehints where appropriate.
  Stop relying on falsey array promotion.
 - FactParseScanner.hack
  Remove an HH_FIXME, since HH\facts_parse does
    have an HHI these days.
  Use ImmVector::toValuesArray() to prefer varray use.

* Prefer darray(x) over x->toArray()

src/AutoloadMap.hack

@@ -12,10 +12,15 @@ namespace Facebook\AutoloadMap;
 /** The main shape of an autoload map.
  *
  * Must match `\HH\autoload_set_paths()`
+ * However, this is nolonger accurate.
+ * The parameter of autoload_set_paths is a
+ * `KeyedContainer<string, KeyedContainer<string, string>>`.
+ * This does sadly not allow for the fallback key,
+ * which is a (function(string, string): bool).
  */
 type AutoloadMap = shape(
-  'class' => array<string, string>,
-  'function' => array<string, string>,
-  'type' => array<string, string>,
-  'constant' => array<string, string>,
+  'class' => darray<string, string>,
+  'function' => darray<string, string>,
+  'type' => darray<string, string>,
+  'constant' => darray<string, string>,
 );

src/ConfigurationLoader.hack

@@ -30,23 +30,19 @@ abstract final class ConfigurationLoader {
   public static function fromJSON(string $json, string $path): Config {
     $decoded = \json_decode($json, /* as array = */ true);
     invariant(
-      \is_array($decoded),
+      $decoded is KeyedContainer<_, _>,
       'Expected configuration file to contain a JSON object, got %s',
       \gettype($decoded),
     );
-    //hackfmt-ignore (else the comment applies to both arguments)
-    return self::fromData(
-        /* HH_IGNORE_ERROR[4110] */ $decoded, 
-        $path
-    );
+    return self::fromData($decoded, $path);
   }
 
   /** Load configuration from decoded data.
    *
    * @param $path arbitrary string - used to create clearer error messages
    */
   public static function fromData(
-    array<string, mixed> $data,
+    KeyedContainer<arraykey, mixed> $data,
     string $path,
   ): Config {
     $failure_handler = TypeAssert\is_nullable_string(
@@ -62,8 +58,7 @@ abstract final class ConfigurationLoader {
         TypeAssert\is_nullable_array_of_strings(
           $data['devRoots'] ?? null,
           'devRoots',
-        ) ??
-          varray[],
+        ),
       ),
       'autoloadFilesBehavior' => TypeAssert\is_nullable_enum(
         AutoloadFilesBehavior::class,
@@ -85,8 +80,7 @@ abstract final class ConfigurationLoader {
         TypeAssert\is_nullable_array_of_strings(
           $data['extraFiles'] ?? null,
           'extraFiles',
-        ) ??
-          varray[],
+        ),
       ),
       'parser' => TypeAssert\is_nullable_enum(
         Parser::class,

src/HHClientFallbackHandler.hack

@@ -95,7 +95,7 @@ class HHClientFallbackHandler extends FailureHandler {
     $this->map = $map;
     $map['failure'] = inst_meth($this, 'handleFailure');
     \HH\autoload_set_paths(
-      /* HH_IGNORE_ERROR[4110] shape as array */ $map,
+      /* HH_IGNORE_ERROR[4110] incorrect hhi */ $map,
       Generated\root(),
     );
 
@@ -230,7 +230,7 @@ class HHClientFallbackHandler extends FailureHandler {
       return null;
     }
 
-    $data = \json_decode($last, /* arrays = */ true);
+    $data = \json_decode($last, /* assoc = */ true);
     if (!\is_array($data)) {
       return null;
     }
@@ -247,7 +247,6 @@ class HHClientFallbackHandler extends FailureHandler {
   }
 
   private function requireFile(string $path): void {
-    /* HH_IGNORE_ERROR[1002] */
-    require ($path);
+    require $path;
   }
 }

src/Merger.hack

@@ -31,8 +31,8 @@ abstract final class Merger {
   }
 
   private static function mergeImpl(
-    Iterable<array<string, string>> $maps,
-  ): array<string, string> {
+    Traversable<darray<string, string>> $maps,
+  ): darray<string, string> {
     $out = darray[];
     foreach ($maps as $map) {
       foreach ($map as $def => $file) {

src/Writer.hack

@@ -152,8 +152,8 @@ final class Writer {
       $add_failure_handler = \sprintf(
         "if (%s::isEnabled()) {\n".
         "  \$handler = new %s();\n".
-        "  \$map['failure'] = varray[\$handler, 'handleFailure'];\n".
-        "  \HH\autoload_set_paths(/* HH_FIXME[4110] */ \$map, Generated\\root());\n".
+        "  \$map['failure'] = inst_meth(\$handler, 'handleFailure');\n".
+        "  \HH\autoload_set_paths(/* HH_FIXME[4110] incorrect hhi */ \$map, Generated\\root());\n".
         "  \$handler->initialize();\n".
         "}",
         $failure_handler,
@@ -236,7 +236,7 @@ function initialize(): void {
   _Private\bootstrap();
   \$map = Generated\\map();
 
-  \HH\autoload_set_paths(/* HH_FIXME[4110] */ \$map, Generated\\root());
+  \HH\autoload_set_paths(/* HH_FIXME[4110] incorrect hhi */ \$map, Generated\\root());
   foreach (\spl_autoload_functions() ?: varray[] as \$autoloader) {
     \spl_autoload_unregister(\$autoloader);
   }

src/builders/ComposerImporter.hack

@@ -26,7 +26,7 @@ final class ComposerImporter implements Builder {
     }
     $this->root = \dirname($path);
     $composer_json = \file_get_contents($path);
-    $composer_config = \json_decode($composer_json, /* as array = */ true);
+    $composer_config = \json_decode($composer_json, /* assoc = */ true);
     $composer_autoload = idx($composer_config, 'autoload');
     if ($composer_autoload === null) {
       return;
@@ -145,13 +145,15 @@ final class ComposerImporter implements Builder {
 
   private static function normalizePSRRoots(
     array<string, mixed> $roots,
-  ): array<string, array<string>> {
+  ): darray<string, varray<string>> {
     $out = darray[];
     foreach ($roots as $k => $v) {
       if ($v is string) {
+        $out[$k] ??= varray[];
         $out[$k][] = $v;
       } else if (\is_array($v)) {
         foreach ($v as $w) {
+          $out[$k] ??= varray[];
           $out[$k][] = $w;
         }
       }

src/builders/FactParseScanner.hack

@@ -105,11 +105,9 @@ final class FactParseScanner implements Builder {
   }
 
   public function getAutoloadMap(): AutoloadMap {
-    /* HH_FIXME[2049] no HHI for \HH\facts_parse */
-    /* HH_FIXME[4107] no HHI for \HH|facts_parse */
     $facts = \HH\facts_parse(
       $this->root,
-      $this->paths->toArray(),
+      $this->paths->toValuesArray(),
       /* force_hh = */ false,
       /* multithreaded = */ true,
     );

src/filters/BasePSRFilter.hack

@@ -69,7 +69,7 @@ abstract class BasePSRFilter implements Builder {
     );
 
     return shape(
-      'class' => $classes->toArray(),
+      'class' => darray($classes),
       'function' => darray[],
       'type' => darray[],
       'constant' => darray[],