coeffects and capabilities (#142)

* feat: add contexts to the methods/funtions

* chore: empty string patch

* chore: test the coeffects functions and change coeffects property to keyset from string

Author: dienesl

composer.json

@@ -3,7 +3,7 @@
     "description": "Hack Codegen is a library for programmatically generating Hack code",
     "keywords": ["code generation", "Hack"],
     "require": {
-        "hhvm": "^4.80",
+        "hhvm": "^4.93",
         "hhvm/hhvm-autoload": "^2.0|^3.0",
         "hhvm/hsl": "^4.0"
     },

src/CodegenFunctionish.hack

@@ -22,6 +22,7 @@ abstract class CodegenFunctionish implements ICodeBuilderRenderer {
   protected string $name;
   protected ?string $body = null;
   protected ?string $docBlock = null;
+  protected ?keyset<string> $contexts = null;
   protected ?string $returnType = null;
   private ?string $fixme = null;
   protected bool $isAsync = false;
@@ -53,6 +54,28 @@ abstract class CodegenFunctionish implements ICodeBuilderRenderer {
     return $this;
   }
 
+  public function addContext(
+    string $context,
+  ): this {
+    if($this->contexts === null) {
+      $this->contexts = keyset<string>[$context];
+    } else {
+      $this->contexts[] = $context;
+    }
+
+    return $this;
+  }
+
+  public function addContexts(
+    Traversable<string> $contexts,
+  ): this {
+    foreach($contexts as $context) {
+      $this->addContext($context);
+    }
+
+    return $this;
+  }
+
   public function setReturnType(string $type): this {
     return $this->setReturnTypef('%s', $type);
   }
@@ -129,6 +152,10 @@ abstract class CodegenFunctionish implements ICodeBuilderRenderer {
     return $this->parameters;
   }
 
+  public function getContexts(): ?keyset<string> {
+    return $this->contexts;
+  }
+
   public function getReturnType(): ?string {
     return $this->returnType;
   }
@@ -151,6 +178,7 @@ abstract class CodegenFunctionish implements ICodeBuilderRenderer {
     $builder = (new HackBuilder($this->config))
       ->add($keywords)
       ->addf('%s(%s)', $this->name, Str\join($this->parameters, ', '))
+      ->addIf($this->contexts !== null, '[' . Str\join($this->contexts ?? keyset[], ', ') . ']')
       ->addIf($this->returnType !== null, ': '.($this->returnType ?? ''));
 
     $code = $builder->getCode();
@@ -183,6 +211,7 @@ abstract class CodegenFunctionish implements ICodeBuilderRenderer {
         ->addLines($parameter_lines)
         ->unindent()
         ->add(')')
+        ->addIf($this->contexts !== null, '[' . Str\join($this->contexts ?? keyset[], ', ') . ']')
         ->addIf($this->returnType !== null, ': '.($this->returnType ?? ''));
 
       return $multi_line_builder->getCode();

tests/CodegenFunctionTest.codegen

@@ -61,6 +61,11 @@ public function getExpensiveNotLikeParent() {
 public async function genExpensiveNotLikeParent() {
 }
 
+!@#$%codegentest:testContexts
+function withContexts()[io]: void {
+  echo 'hello world';
+}
+
 !@#$%codegentest:testParams
 function getName(string $name) {
   return $name . $name;

tests/CodegenFunctionTest.hack

@@ -24,6 +24,17 @@ final class CodegenFunctionTest extends CodegenBaseTest {
     expect_with_context(static::class, $code)->toBeUnchanged();
   }
 
+  public function testContexts(): void {
+    $code = $this
+      ->getCodegenFactory()
+      ->codegenFunction('withContexts')
+      ->addContext('io')
+      ->setReturnType('void')
+      ->setBody('echo \'hello world\';')
+      ->render();
+    expect_with_context(static::class, $code)->toBeUnchanged();
+  }
+
   public function testParams(): void {
     $code = $this
       ->getCodegenFactory()