From 63f7de83b81720f350b8de3f399f609daeeb0df2 Mon Sep 17 00:00:00 2001
From: Alex Butler <alexheretic@gmail.com>
Date: Wed, 13 Feb 2019 11:41:32 +0000
Subject: [PATCH] feat: definitions for out-of-project files

---
 lib/auto-languageclient.ts | 51 +++++++++++++++++++++++++++++++++++---
 lib/server-manager.ts      |  9 +++++++
 2 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/lib/auto-languageclient.ts b/lib/auto-languageclient.ts
index 410e1011..bb39d757 100644
--- a/lib/auto-languageclient.ts
+++ b/lib/auto-languageclient.ts
@@ -26,7 +26,13 @@ import * as Utils from "./utils"
 import { Socket } from "net"
 import { LanguageClientConnection } from "./languageclient"
 import { ConsoleLogger, FilteredLogger, Logger } from "./logger"
-import { LanguageServerProcess, ServerManager, ActiveServer } from "./server-manager.js"
+import {
+  LanguageServerProcess,
+  ServerManager,
+  ActiveServer,
+  normalizePath,
+  considerAdditionalPath,
+} from "./server-manager.js"
 import { Disposable, CompositeDisposable, Point, Range, TextEditor } from "atom"
 import * as ac from "atom/autocomplete-plus"
 import { basename } from "path"
@@ -391,6 +397,7 @@ export default class AutoLanguageClient {
       connection,
       capabilities: initializeResponse.capabilities,
       disposable: new CompositeDisposable(),
+      additionalPaths: new Set<string>(),
     }
     this.postInitialization(newServer)
     connection.initialized()
@@ -481,10 +488,22 @@ export default class AutoLanguageClient {
   /** (Optional) Finds the project path. If there is a custom logic for finding projects override this method. */
   protected determineProjectPath(textEditor: TextEditor): string | null {
     const filePath = textEditor.getPath()
-    if (filePath == null) {
+    // TODO can filePath be null
+    if (filePath === null || filePath === undefined) {
       return null
     }
-    return this._serverManager.getNormalizedProjectPaths().find((d) => filePath.startsWith(d)) || null
+    const projectPath = this._serverManager.getNormalizedProjectPaths().find((d) => filePath.startsWith(d))
+    if (projectPath !== undefined) {
+      return projectPath
+    }
+
+    const serverWithClaim = this._serverManager
+      .getActiveServers()
+      .find((server) => server.additionalPaths?.has(path.dirname(filePath)))
+    if (serverWithClaim !== undefined) {
+      return normalizePath(serverWithClaim.projectPath)
+    }
+    return null
   }
 
   /**
@@ -678,7 +697,21 @@ export default class AutoLanguageClient {
     }
 
     this.definitions = this.definitions || new DefinitionAdapter()
-    return this.definitions.getDefinition(server.connection, server.capabilities, this.getLanguageName(), editor, point)
+    const query = await this.definitions.getDefinition(
+      server.connection,
+      server.capabilities,
+      this.getLanguageName(),
+      editor,
+      point
+    )
+
+    if (query !== null && this.serversSupportDefinitionDestinations() && server.additionalPaths !== undefined) {
+      for (const def of query.definitions) {
+        considerAdditionalPath(server as ActiveServer & { additionalPaths: Set<string> }, def.path)
+      }
+    }
+
+    return query
   }
 
   // Outline View via LS documentSymbol---------------------------------
@@ -965,6 +998,16 @@ export default class AutoLanguageClient {
       .forEach((line) => this.logger.warn(`stderr ${line}`))
   }
 
+  /**
+   * Indicates that the language server can support LSP functionality for out of project files indicated by
+   * `textDocument/definition` responses.
+   *
+   * Default: false
+   */
+  protected serversSupportDefinitionDestinations(): boolean {
+    return false
+  }
+
   private getServerAdapter<T extends keyof ServerAdapters>(
     server: ActiveServer,
     adapter: T
diff --git a/lib/server-manager.ts b/lib/server-manager.ts
index a5109ee9..357de66f 100644
--- a/lib/server-manager.ts
+++ b/lib/server-manager.ts
@@ -22,6 +22,8 @@ export interface ActiveServer {
   process: LanguageServerProcess
   connection: ls.LanguageClientConnection
   capabilities: ls.ServerCapabilities
+  /** Out of project directories that this server can also support. */
+  additionalPaths?: Set<string>
 }
 
 interface RestartCounter {
@@ -343,3 +345,10 @@ export function normalizedProjectPathToWorkspaceFolder(normalizedProjectPath: st
 export function normalizePath(projectPath: string): string {
   return !projectPath.endsWith(path.sep) ? path.join(projectPath, path.sep) : projectPath
 }
+
+/** Considers a path for inclusion in `additionalPaths`. */
+export function considerAdditionalPath(server: ActiveServer & { additionalPaths: Set<string> }, additionalPath: string): void {
+  if (!additionalPath.startsWith(server.projectPath)) {
+    server.additionalPaths.add(path.dirname(additionalPath))
+  }
+}