Add support for method/property completion

fixtures/completion.php

@@ -0,0 +1,4 @@
+<?php
+
+$obj = new TestClass;
+$obj->t

src/DefinitionResolver.php

@@ -327,7 +327,7 @@ class DefinitionResolver
      * @param \PhpParser\Node\Expr $expr
      * @return \phpDocumentor\Type
      */
-    private function resolveExpressionNodeToType(Node\Expr $expr): Type
+    public function resolveExpressionNodeToType(Node\Expr $expr): Type
     {
         if ($expr instanceof Node\Expr\Variable) {
             if ($expr->name === 'this') {

src/LanguageServer.php

@@ -11,7 +11,8 @@ use LanguageServer\Protocol\{
     MessageType,
     InitializeResult,
     SymbolInformation,
-    TextDocumentIdentifier
+    TextDocumentIdentifier,
+    CompletionOptions
 };
 use AdvancedJsonRpc;
 use Sabre\Event\{Loop, Promise};
@@ -140,6 +141,10 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
         $serverCapabilities->referencesProvider = true;
         // Support "Hover"
         $serverCapabilities->hoverProvider = true;
+        // Support "Completion"
+        $serverCapabilities->completionProvider = new CompletionOptions;
+        $serverCapabilities->completionProvider->resolveProvider = false;
+        $serverCapabilities->completionProvider->triggerCharacters = ['$', '>'];
 
         return new InitializeResult($serverCapabilities);
     }

src/Protocol/CompletionItem.php

@@ -69,6 +69,24 @@ class CompletionItem
      */
     public $textEdit;
 
+    /**
+     * An optional array of additional text edits that are applied when
+     * selecting this completion. Edits must not overlap with the main edit
+     * nor with themselves.
+     *
+     * @var TextEdit[]|null
+     */
+    public $additionalTextEdits;
+
+    /**
+     * An optional command that is executed *after* inserting this completion. *Note* that
+     * additional modifications to the current document should be described with the
+     * additionalTextEdits-property.
+     *
+     * @var Command|null
+     */
+    public $command;
+
     /**
      * An data entry field that is preserved on a completion item between
      * a completion and a completion resolve request.
@@ -76,4 +94,43 @@ class CompletionItem
      * @var mixed
      */
     public $data;
+
+    /**
+     * @param string          $label
+     * @param int|null        $kind
+     * @param string|null     $detail
+     * @param string|null     $documentation
+     * @param string|null     $sortText
+     * @param string|null     $filterText
+     * @param string|null     $insertQuery
+     * @param TextEdit|null   $textEdit
+     * @param TextEdit[]|null $additionalTextEdits
+     * @param Command|null    $command
+     * @param mixed|null      $data
+     */
+    public function __construct(
+        string $label = null,
+        int $kind = null,
+        string $detail = null,
+        string $documentation = null,
+        string $sortText = null,
+        string $filterText = null,
+        string $insertQuery = null,
+        TextEdit $textEdit = null,
+        array $additionalTextEdits = null,
+        Command $command = null,
+        $data = null
+    ) {
+        $this->label = $label;
+        $this->kind = $kind;
+        $this->detail = $detail;
+        $this->documentation = $documentation;
+        $this->sortText = $sortText;
+        $this->filterText = $filterText;
+        $this->insertQuery = $insertQuery;
+        $this->textEdit = $textEdit;
+        $this->additionalTextEdits = $additionalTextEdits;
+        $this->command = $command;
+        $this->data = $data;
+    }
 }

src/Protocol/CompletionItemKind.php

@@ -13,7 +13,7 @@ abstract class CompletionItemKind
     const CONSTRUCTOR = 4;
     const FIELD = 5;
     const VARIABLE = 6;
-    const _CLASS = 7;
+    const CLASS_ = 7;
     const INTERFACE = 8;
     const MODULE = 9;
     const PROPERTY = 10;

src/Protocol/CompletionOptions.php

@@ -11,14 +11,14 @@ class CompletionOptions
      * The server provides support to resolve additional information for a completion
      * item.
      *
-     * @var bool
+     * @var bool|null
      */
     public $resolveProvider;
 
     /**
      * The characters that trigger completion automatically.
      *
-     * @var string|null
+     * @var string[]|null
      */
     public $triggerCharacters;
 }

src/Server/TextDocument.php

@@ -18,8 +18,12 @@ use LanguageServer\Protocol\{
     SymbolInformation,
     ReferenceContext,
     Hover,
-    MarkedString
+    MarkedString,
+    SymbolKind,
+    CompletionItem,
+    CompletionItemKind
 };
+use phpDocumentor\Reflection\Types;
 use Sabre\Event\Promise;
 use function Sabre\Event\coroutine;
 
@@ -210,4 +214,64 @@ class TextDocument
             return new Hover($contents, $range);
         });
     }
+
+    /**
+     * The Completion request is sent from the client to the server to compute completion items at a given cursor
+     * position. Completion items are presented in the IntelliSense user interface. If computing full completion items
+     * is expensive, servers can additionally provide a handler for the completion item resolve request
+     * ('completionItem/resolve'). This request is sent when a completion item is selected in the user interface. A
+     * typically use case is for example: the 'textDocument/completion' request doesn't fill in the documentation
+     * property for returned completion items since it is expensive to compute. When the item is selected in the user
+     * interface then a 'completionItem/resolve' request is sent with the selected completion item as a param. The
+     * returned completion item should have the documentation property filled in.
+     *
+     * @param TextDocumentIdentifier The text document
+     * @param Position $position The position
+     * @return Promise <CompletionItem[]|CompletionList>
+     */
+    public function completion(TextDocumentIdentifier $textDocument, Position $position): Promise
+    {
+        return coroutine(function () use ($textDocument, $position) {
+            $document = yield $this->project->getOrLoadDocument($textDocument->uri);
+            $node = $document->getNodeAtPosition($position);
+            if ($node === null) {
+                return [];
+            }
+            if ($node instanceof Node\Expr\Error) {
+                $node = $node->getAttribute('parentNode');
+            }
+            if ($node instanceof Node\Expr\PropertyFetch) {
+                // Resolve object
+                $objType = $this->definitionResolver->resolveExpressionNodeToType($node->var);
+                if ($objType instanceof Types\Object_ && $objType->getFqsen() !== null) {
+                    $prefix = substr((string)$objType->getFqsen(), 1) . '::';
+                    if (is_string($node->name)) {
+                        $prefix .= $node->name;
+                    }
+                    $prefixLen = strlen($prefix);
+                    $items = [];
+                    foreach ($this->project->getDefinitions() as $fqn => $def) {
+                        if (substr($fqn, 0, $prefixLen) === $prefix) {
+                            $item = new CompletionItem;
+                            $item->label = $def->symbolInformation->name;
+                            if ($def->type) {
+                                $item->detail = (string)$def->type;
+                            }
+                            if ($def->documentation) {
+                                $item->documentation = $def->documentation;
+                            }
+                            if ($def->symbolInformation->kind === SymbolKind::PROPERTY) {
+                                $item->kind = CompletionItemKind::PROPERTY;
+                            } else if ($def->symbolInformation->kind === SymbolKind::METHOD) {
+                                $item->kind = CompletionItemKind::METHOD;
+                            }
+                            $items[] = $item;
+                        }
+                    }
+                    return $items;
+                }
+            }
+            return [];
+        });
+    }
 }

tests/LanguageServerTest.php

@@ -36,7 +36,10 @@ class LanguageServerTest extends TestCase
                 'textDocumentSync' => TextDocumentSyncKind::FULL,
                 'documentSymbolProvider' => true,
                 'hoverProvider' => true,
-                'completionProvider' => null,
+                'completionProvider' => (object)[
+                    'resolveProvider' => false,
+                    'triggerCharacters' => ['$', '>']
+                ],
                 'signatureHelpProvider' => null,
                 'definitionProvider' => true,
                 'referencesProvider' => true,
@@ -61,7 +64,7 @@ class LanguageServerTest extends TestCase
             if ($msg->body->method === 'window/logMessage' && $promise->state === Promise::PENDING) {
                 if ($msg->body->params->type === MessageType::ERROR) {
                     $promise->reject(new Exception($msg->body->params->message));
-                } else if (strpos($msg->body->params->message, 'All 10 PHP files parsed') !== false) {
+                } else if (strpos($msg->body->params->message, 'All 11 PHP files parsed') !== false) {
                     $promise->fulfill();
                 }
             }
@@ -106,7 +109,7 @@ class LanguageServerTest extends TestCase
                     if ($promise->state === Promise::PENDING) {
                         $promise->reject(new Exception($msg->body->params->message));
                     }
-                } else if (strpos($msg->body->params->message, 'All 10 PHP files parsed') !== false) {
+                } else if (strpos($msg->body->params->message, 'All 11 PHP files parsed') !== false) {
                     // Indexing finished
                     $promise->fulfill();
                 }

tests/Server/TextDocument/CompletionTest.php

@@ -0,0 +1,55 @@
+<?php
+declare(strict_types = 1);
+
+namespace LanguageServer\Tests\Server\TextDocument;
+
+use PHPUnit\Framework\TestCase;
+use LanguageServer\Tests\MockProtocolStream;
+use LanguageServer\{Server, LanguageClient, Project};
+use LanguageServer\Protocol\{TextDocumentIdentifier, Position, ClientCapabilities, CompletionItem, CompletionItemKind};
+use function LanguageServer\pathToUri;
+
+class CompletionTest extends TestCase
+{
+    /**
+     * @var Server\TextDocument
+     */
+    private $textDocument;
+
+    /**
+     * @var string
+     */
+    private $completionUri;
+
+    public function setUp()
+    {
+        $client = new LanguageClient(new MockProtocolStream, new MockProtocolStream);
+        $project = new Project($client, new ClientCapabilities);
+        $this->completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion.php');
+        $project->loadDocument(pathToUri(__DIR__ . '/../../../fixtures/global_symbols.php'));
+        $project->openDocument($this->completionUri, file_get_contents($this->completionUri));
+        $this->textDocument = new Server\TextDocument($project, $client);
+    }
+
+    public function testCompletion()
+    {
+        $items = $this->textDocument->completion(
+            new TextDocumentIdentifier($this->completionUri),
+            new Position(3, 7)
+        )->wait();
+        $this->assertEquals([
+            new CompletionItem(
+                'testProperty',
+                CompletionItemKind::PROPERTY,
+                '\TestClass', // Type of the property
+                'Reprehenderit magna velit mollit ipsum do.'
+            ),
+            new CompletionItem(
+                'testMethod',
+                CompletionItemKind::METHOD,
+                '\TestClass', // Return type of the method
+                'Non culpa nostrud mollit esse sunt laboris in irure ullamco cupidatat amet.'
+            )
+        ], $items);
+    }
+}