Add HHClientLinter

src/Linters/HHClientLintError.hack

@@ -0,0 +1,55 @@
+/*
+ *  Copyright (c) 2017-present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the MIT license found in the
+ *  LICENSE file in the root directory of this source tree.
+ *
+ */
+
+namespace Facebook\HHAST;
+
+enum ArcanistLintSeverityEnum: string as string {
+  ADVICE = 'advice';
+  AUTOFIX = 'autofix';
+  WARNING = 'warning';
+  ERROR = 'error';
+  DISABLED = 'disabled';
+}
+
+final class HHClientLintError extends LintError {
+
+  const type TJSONError = shape(
+    'descr' => string,
+    'severity' => ArcanistLintSeverityEnum,
+    'path' => string,
+    'line' => int,
+    'start' => int,
+    'end' => int,
+    'code' => int,
+    'bypass_changed_lines' => bool,
+    'original' => string,
+    'replacement' => string,
+  );
+
+  public function __construct(
+    HHClientLinter $linter,
+    private this::TJSONError $error,
+  ) {
+    parent::__construct($linter, $error['descr']);
+  }
+
+  <<__Override>>
+  public function getPosition(): (int, int) {
+    return tuple($this->error['line'], $this->error['end']);
+  }
+
+  <<__Override>>
+  public function getRange(): ((int, int), (int, int)) {
+    return tuple(
+      tuple($this->error['line'], $this->error['start']),
+      tuple($this->error['line'], $this->error['end']),
+    );
+  }
+
+}

src/Linters/HHClientLinter.hack

@@ -0,0 +1,52 @@
+/*
+ *  Copyright (c) 2017-present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the MIT license found in the
+ *  LICENSE file in the root directory of this source tree.
+ *
+ */
+
+namespace Facebook\HHAST;
+
+use type Facebook\HHAST\{BaseLinter};
+use namespace Facebook\TypeAssert;
+use namespace HH\Lib\{C, Vec};
+
+/**
+ * A linter as a proxy invoking `hh_client --lint`.
+ */
+final class HHClientLinter extends BaseLinter {
+
+  const type TConfig = shape();
+
+  const type TJSONResult = shape(
+    'errors' => vec<HHClientLintError::TJSONError>,
+    'version' => string,
+  );
+
+  <<__Override>>
+  public async function getLintErrorsAsync(
+  ): Awaitable<vec<HHClientLintError>> {
+    $lines = await __Private\execute_async(
+      'hh_client',
+      '--lint',
+      $this->getFile()->getPath(),
+      '--json',
+      '--from',
+      'hhast',
+    );
+    $hh_client_lint_result = TypeAssert\matches<this::TJSONResult>(
+      \json_decode(
+        C\firstx($lines),
+        /* assoc = */ true,
+        /* depth = */ 512,
+        \JSON_FB_HACK_ARRAYS,
+      ),
+    );
+    return Vec\map(
+      $hh_client_lint_result['errors'],
+      $error ==> new HHClientLintError($this, $error),
+    );
+  }
+}

tests/HHClientLinterTest.hack

@@ -0,0 +1,58 @@
+/*
+ *  Copyright (c) 2017-present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the MIT license found in the
+ *  LICENSE file in the root directory of this source tree.
+ *
+ */
+
+namespace Facebook\HHAST;
+use namespace HH\Lib\Str;
+
+final class HHClientLinterTest extends TestCase {
+  use LinterTestTrait;
+
+  /**
+   * The temporary directory to include testing source files to lint.
+   *
+   * Note that the temporary directory must be under the current directory,
+   * otherwise hh_client will not work.
+   */
+  const string TMP_DIR = __DIR__.'/../.var/tmp/hhast/HHClientLinterTest';
+
+  public function getCleanExamples(): vec<(string)> {
+    return vec[
+      tuple("<?hh\nclass Foo {}"),
+    ];
+  }
+
+  protected function getLinter(string $file): BaseLinter {
+    $ext = Str\strip_suffix($file, '.in')
+      |> Str\ends_with($$, '.php')
+      |> $$ ? 'php' : 'hack';
+    $hh_client_tmp_file =
+      self::TMP_DIR.'/'.\bin2hex(\random_bytes(16)).'.'.$ext;
+    \copy($file, $hh_client_tmp_file);
+    return HHClientLinter::fromPath($hh_client_tmp_file);
+  }
+
+  <<__Override>>
+  public static async function beforeFirstTestAsync(): Awaitable<void> {
+    $mode = 0777;
+    $recursive = true;
+    \mkdir(self::TMP_DIR, $mode, $recursive);
+  }
+
+  <<__Override>>
+  public static async function afterLastTestAsync(): Awaitable<void> {
+    foreach (\scandir(self::TMP_DIR) as $file) {
+      $path_file = self::TMP_DIR.'/'.$file;
+      if (\is_file($path_file)) {
+        \unlink($path_file);
+      }
+    }
+    \rmdir(self::TMP_DIR);
+  }
+
+}

tests/examples/HHClientLinter/invalid_null_check.hack.expect

@@ -0,0 +1,7 @@
+[
+    {
+        "blame": null,
+        "blame_pretty": null,
+        "description": "Invalid null check: This expression will always return `false`.\nA value of type `int` can never be null."
+    }
+]

tests/examples/HHClientLinter/invalid_null_check.hack.in

@@ -0,0 +1,17 @@
+<?hh // strict
+
+/**
+ * Copyright (c) 2016, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ */
+
+function invalid_null_check(): void {
+  $cannot_be_null = 42;
+  if ($cannot_be_null is null) {
+    throw new Exception();
+  }
+}