fix stringify_typehint() bugs (#35)

...mostly by delegating to the new ScannedTypehint::getTypeText(), but also a few other fixes, e.g. a few places were calling stringify_typehint() incorrectly.

This is the diff when running on itself: https://gist.github.com/jjergus/bcf87815d8ca29f661c60dc02be4f396 (all changes are good)

.travis.yml

@@ -2,7 +2,7 @@ sudo: required
 language: generic
 services: docker
 env:
-- HHVM_VERSION=4.14-latest
+- HHVM_VERSION=4.21-latest
 - HHVM_VERSION=latest
 - HHVM_VERSION=nightly
 install:

composer.json

@@ -7,7 +7,7 @@
     "hhvm/hsl": "^4.0",
     "facebook/fbmarkdown": "^1.0",
     "facebook/hh-clilib": "^2.1.0",
-    "facebook/definition-finder": "^2.0.0",
+    "facebook/definition-finder": "^2.12.3",
     "hhvm/hhast": "^4.14"
   },
   "require-dev": {

src/PageSections/InterfaceSynopsis.hack

@@ -143,13 +143,13 @@ final class InterfaceSynopsis extends PageSection {
 
     $ret .= $c->getShortName();
 
-    $p = $c->getParentClassName();
+    $p = $c->getParentClassInfo();
     if ($p !== null) {
-      $ret .= ' extends '._Private\ns_normalize_type($ns, $p);
+      $ret .= ' extends '._Private\stringify_typehint($ns, $p);
     }
-    if ($interfaces = $c->getInterfaceNames()) {
+    if ($interfaces = $c->getInterfaceInfo()) {
       $ret .= $interfaces
-        |> Vec\map($$, $i ==> _Private\ns_normalize_type($ns, $i))
+        |> Vec\map($$, $i ==> _Private\stringify_typehint($ns, $i))
         |> Str\join($$, ', ')
         |> ' implements '.$$;
     }

src/PageSections/TypeDeclaration.hack

@@ -40,19 +40,24 @@ final class TypeDeclaration extends PageSection {
       $code .= 'newtype ';
     }
 
-    $code .= _Private\ns_normalize_type($ns, $t->getName());
+    $code .= $t->getShortName();
 
     if ($t is ScannedType) {
-      $code .= ' = '.
-        _Private\stringify_typehint(
-          $t->getNamespaceName(),
-          $t->getAliasedType(),
-        ).
-        ';';
-    } else {
-      $code .= ';';
+      $code .= ' = ';
+      // We want custom multi-line formatting for shapes here, so not calling
+      // stringify_typehint() for those. Note that we still use the default
+      // stringify_typehint() for shapes in other places, e.g. as function
+      // arguments.
+      $code .= $t->getAliasedType()->isShape()
+        ? _Private\stringify_shape($ns, $t->getAliasedType()->getShapeFields())
+        : _Private\stringify_typehint(
+            $t->getNamespaceName(),
+            $t->getAliasedType(),
+          );
     }
 
+    $code .= ';';
+
     return Str\format("```Hack\n%s\n```", $code);
   }
 }

src/PageSections/_Private/stringify_generic.hack

@@ -23,15 +23,18 @@ function stringify_generic(
   } else {
     $base = '';
   }
-  $base .= ns_normalize_type($ns, $generic->getName());
+  $base .= $generic->getName();
 
   $constraints = $generic->getConstraints();
   if (C\is_empty($constraints)) {
     return $base;
   }
 
   return $constraints
-    |> Vec\map($$, $c ==> $c['relationship'].' '.$c['type']->getTypeText())
+    |> Vec\map(
+      $$,
+      $c ==> $c['relationship'].' '.stringify_typehint($ns, $c['type']),
+    )
     |> Str\join($$, ' ')
     |> $base.' '.$$;
 }

src/PageSections/_Private/stringify_typehint.hack

@@ -9,29 +9,18 @@
 
 namespace Facebook\HHAPIDoc\PageSections\_Private;
 
-use type Facebook\DefinitionFinder\ScannedTypehint;
-use namespace HH\Lib\{C, Str, Vec};
+use type Facebook\DefinitionFinder\{ScannedTypehint, TypeTextOptions};
 
+/**
+ * Render `$type` as concisely and unambiguously as possible in the current
+ * namespace.
+ */
 function stringify_typehint(
   string $ns,
   ScannedTypehint $type,
 ): string {
-  $s = $type->isNullable() ? '?' : '';
-  if ($type->isShape()) {
-    return $s.stringify_shape($ns, $type->getShapeFields());
-  }
-  invariant($type->getTypeName() !== 'shape', 'got a shape thats not a shape');
-  $s .= ns_normalize_type($ns, $type->getTypeName());
-
-  $generics = $type->getGenericTypes();
-  if (C\is_empty($generics)) {
-    return $s;
-  }
-
-  $s .= $generics
-    |> Vec\map($$, $sub ==> stringify_typehint($ns, $sub))
-    |> Str\join($$, ', ')
-    |> '<'.$$.'>';
-
-  return $s;
+  // This just delegates to the implementation in ScannedTypehint, but we keep
+  // this function here to ensure that we always call getTypeText() consistently
+  // with the same options.
+  return $type->getTypeText($ns, TypeTextOptions::STRIP_AUTOIMPORTED_NAMESPACE);
 }