Merge pull request #66 from slackhq/ih_top_level_ref_aliases

Alias top-level refs

Author: ianhoffman

src/Codegen/Codegen.php

@@ -16,6 +16,7 @@
 };
 
 final class Codegen implements IBuilder {
+  use Factory;
 
   const type TValidatorRefsUniqueConfig = shape(
     /* The root path where all of the schemas live */
@@ -139,7 +140,7 @@ private function __construct(private dict<arraykey, mixed> $schema, private self
       $this->file->setNamespace($validatorConfig['namespace']);
     }
 
-    $context = new Context(
+    $this->ctx = new Context(
       $this->config,
       $this->cg,
       $this->getJsonSchemaCodegenConfig(),
@@ -148,7 +149,7 @@ private function __construct(private dict<arraykey, mixed> $schema, private self
       $this->file,
     );
     $typed_schema = type_assert_type($this->schema, TSchema::class);
-    $this->builder = new SchemaBuilder($context, '', $typed_schema, $this->class);
+    $this->builder = new SchemaBuilder($this->ctx, '', $typed_schema, $this->class);
 
     $this->sanitizeString = $validatorConfig['sanitize_string'] ?? null;
   }
@@ -258,8 +259,10 @@ public function build(): this {
     $this->builder->build();
 
     if ($this->builder->isUniqueRef()) {
-      // No need to do anything, we're building a top-level ref.
-      return $this;
+      // Add a type aliasing the referenced type
+      $this->file->addBeforeType(
+        $this->getHackCodegenFactory()->codegenType($this->getType())->setType($this->builder->getType()),
+      );
     }
 
     $this->class = $this->class
@@ -282,7 +285,12 @@ public function build(): this {
 
   private function getCodegenClassProcessMethod(): CodegenMethod {
     $hb = new HackBuilder($this->getHackCodegenConfig());
-    $hb->addMultilineCall('return self::check', vec['$this->input', '$this->pointer']);
+    if ($this->builder->isUniqueRef()) {
+      $obj = $this->builder->getClassName();
+    } else {
+      $obj = 'self';
+    }
+    $hb->addMultilineCall(Str\format('return %s::check', $obj), vec['$this->input', '$this->pointer']);
 
     return $this->cg
       ->codegenMethod('process')
@@ -301,11 +309,20 @@ public function getFile(): CodegenFile {
   }
 
   public function getClassName(): string {
-    return $this->builder->getClassName();
+    // Whether or not we're generating a unique ref,
+    // we'll always end up outputting a new class.
+    return $this->generateClassName($this->class->getName());
   }
 
   public function getType(): string {
-    return $this->builder->getType();
+    if ($this->builder->isUniqueRef()) {
+      // Generating an alias to a unique ref.
+      // Don't re-use the referenced type's name; instead,
+      // generate a new type pointing to it.
+      return $this->generateTypeName($this->getClassName());
+    } else {
+      return $this->builder->getType();
+    }
   }
 
   public function isArrayKeyType(): bool {

tests/TopLevelRefValidatorTest.hack

@@ -0,0 +1,43 @@
+namespace Slack\Hack\JsonSchema\Tests;
+
+use type Slack\Hack\JsonSchema\Tests\Generated\TopLevelRefValidator;
+
+final class TopLevelRefValidatorTest extends BaseCodegenTestCase {
+
+  <<__Override>>
+  public static async function beforeFirstTestAsync(): Awaitable<void> {
+    $ret = self::getBuilder(
+      'top-level-ref.json',
+      'TopLevelRefValidator',
+      shape(
+        'refs' => shape(
+          'unique' => shape(
+            'source_root' => __DIR__,
+            'output_root' => __DIR__.'/examples/codegen',
+          ),
+        ),
+      ),
+    );
+    $ret['codegen']->build();
+    require_once($ret['path']);
+  }
+
+  public function testTopLevelRef(): void {
+    $cases = vec[
+      shape(
+        'input' => darray['integer' => 1000],
+        'output' => darray['integer' => 1000],
+        'valid' => true,
+      ),
+      shape(
+        'input' => darray['integer' => 0],
+        'output' => darray['integer' => 0],
+        'valid' => true,
+      ),
+      shape('input' => darray['integer' => '1000'], 'valid' => false),
+      shape('input' => darray['integer' => 1000.00], 'valid' => false),
+    ];
+
+    $this->expectCases($cases, $input ==> new TopLevelRefValidator($input));
+  }
+}