Add --disable-on-change option

src/Psalm/Checker/ProjectChecker.php

@@ -145,6 +145,11 @@ class ProjectChecker
      */
     public $only_replace_php_types_with_non_docblock_types = false;
 
+    /**
+     * @var ?int
+     */
+    public $onchange_line_limit;
+
     const TYPE_CONSOLE = 'console';
     const TYPE_PYLINT = 'pylint';
     const TYPE_JSON = 'json';

src/Psalm/LanguageServer/LanguageServer.php

@@ -168,7 +168,8 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
                 if ($this->textDocument === null) {
                     $this->textDocument = new TextDocument(
                         $this,
-                        $this->project_checker->codebase
+                        $this->project_checker->codebase,
+                        $this->project_checker->onchange_line_limit
                     );
                 }
 

src/Psalm/LanguageServer/Server/TextDocument.php

@@ -61,12 +61,17 @@ class TextDocument
      */
     protected $codebase;
 
+    /** @var ?int */
+    protected $onchange_line_limit;
+
     public function __construct(
         LanguageServer $server,
-        Codebase $codebase
+        Codebase $codebase,
+        ?int $onchange_line_limit
     ) {
         $this->server = $server;
         $this->codebase = $codebase;
+        $this->onchange_line_limit = $onchange_line_limit;
     }
 
     /**
@@ -130,6 +135,19 @@ class TextDocument
 
         $time = microtime(true);
         $this->codebase->addTemporaryFileChanges($file_path, $contentChanges);
+
+        if ($this->onchange_line_limit !== null) {
+            if ($this->onchange_line_limit === 0) {
+                return;
+            }
+
+            $c = $this->codebase->getFileContents($file_path);
+
+            if (substr_count($c, "\n") > $this->onchange_line_limit) {
+                return;
+            }
+        }
+
         $this->server->analyzePath($file_path);
         $this->server->emitIssues($textDocument->uri);
         $diff = microtime(true) - $time;

src/psalm-language-server.php

@@ -24,6 +24,7 @@ $valid_long_options = [
     'use-ini-defaults',
     'version',
     'tcp:',
+    'disable-on-change::'
 ];
 
 $args = array_slice($argv, 1);
@@ -38,7 +39,10 @@ array_map(
         if (substr($arg, 0, 2) === '--' && $arg !== '--') {
             $arg_name = preg_replace('/=.*$/', '', substr($arg, 2));
 
-            if (!in_array($arg_name, $valid_long_options) && !in_array($arg_name . ':', $valid_long_options)) {
+            if (!in_array($arg_name, $valid_long_options)
+                && !in_array($arg_name . ':', $valid_long_options)
+                && !in_array($arg_name . '::', $valid_long_options)
+            ) {
                 echo 'Unrecognised argument "--' . $arg_name . '"' . PHP_EOL
                     . 'Type --help to see a list of supported arguments'. PHP_EOL;
                 exit(1);
@@ -112,6 +116,9 @@ Options:
     --tcp=url
         Use TCP mode (by default Psalm uses STDIO)
 
+    --disable-on-change[=line-number-threshold]
+        If added, the language server will not respond to onChange events.
+        You can also specify a line count over which Psalm will not run on-change events.
 HELP;
 
     exit;
@@ -214,6 +221,13 @@ $project_checker = new ProjectChecker(
     $providers
 );
 
+error_log(var_export($options, true));
+
+if (isset($options['disable-on-change'])) {
+    error_log('disabling on change');
+    $project_checker->onchange_line_limit = (int) $options['disable-on-change'];
+}
+
 $config->visitComposerAutoloadFiles($project_checker);
 
 if ($find_dead_code) {

tests/FileUpdates/TemporaryUpdateTest.php

@@ -678,6 +678,33 @@ class TemporaryUpdateTest extends \Psalm\Tests\TestCase
                 ],
                 'error_positions' => [[], [197]],
             ],
+            'addUseShouldValidate' => [
+                [
+                    [
+                        getcwd() . DIRECTORY_SEPARATOR . 'A.php' => '<?php
+                            namespace Foo;
+
+                            class A {
+                                public function foo() : void {
+                                    throw new Exception();
+                                }
+                            }',
+                    ],
+                    [
+                        getcwd() . DIRECTORY_SEPARATOR . 'A.php' => '<?php
+                            namespace Foo;
+
+                            use Exception;
+
+                            class A {
+                                public function foo() : void {
+                                    throw new Exception();
+                                }
+                            }',
+                    ],
+                ],
+                'error_positions' => [[197], []],
+            ],
         ];
     }
 }