feat(java): share JDT LS across builds in a project window (#2272)

* feat(java): share JDT LS across builds in a project window

* fix(java): wait for JDT restart before launch requests

* fix(host): give relay final replies ten seconds of EOF grace

relay::tests::final_responses_keep_flowing_after_input_eof flakes on
Windows CI: the target writes one byte per second for seven seconds
after input EOF, but the relay only waits five idle seconds, so a
slow first byte makes the relay return with nothing received.

Raise EOF_GRACE to ten seconds and update the companion test's
server wait and elapsed bound to match.

Refs #2272 (Windows CI failure)

---------

Co-authored-by: arookieofc <[email protected]>

src/bindings.ts

@@ -5271,6 +5271,8 @@ export type JavaSettings = {
 	 *  (VS Code's `java.jdt.ls.vmargs`).
 	 */
 	jdtlsVmArgs?: string,
+	/**  Share one JDT LS across builds in an ordinary project window; other windows remain separate. */
+	jdtlsShared?: boolean,
 	/**  Build Tools › Maven. */
 	maven?: MavenSettings,
 	/**  Build Tools › Gradle. */

src/features/settings/__tests__/dialog.test.tsx

@@ -514,6 +514,94 @@ describe("Settings dialog", () => {
       expect(settingsSet.mock.calls).toEqual([["global", "languages.java.jdtlsVmArgs", '"-Xmx2g"']]);
     });
 
+    it("stages shared JDT LS in the project and writes it on Apply", async () => {
+      const dialog = await openDialog("languages.java");
+      fireEvent.click(within(dialog).getByRole("radio", { name: "This project" }));
+      const checkbox = within(dialog).getByRole("checkbox", { name: "Share JDT LS across builds" });
+      expect(checkbox).not.toBeChecked();
+      fireEvent.click(checkbox);
+      expect(checkbox).toBeChecked();
+      expect(settingsSet).not.toHaveBeenCalled();
+      await act(async () => fireEvent.click(within(dialog).getByRole("button", { name: "Apply" })));
+      expect(settingsSet.mock.calls).toEqual([["project", "languages.java.jdtlsShared", "true"]]);
+    });
+
+    it("keeps the global shared JDT LS preference separate from the project's override", async () => {
+      global = setAt(global, "languages.java.jdtlsShared", true);
+      current = setAt(global, "languages.java.jdtlsShared", false);
+      useProject.setState({ settings: current });
+      const dialog = await openDialog("languages.java");
+      fireEvent.click(within(dialog).getByRole("radio", { name: "This project" }));
+      expect(within(dialog).getByRole("checkbox", { name: "Share JDT LS across builds" })).not.toBeChecked();
+      fireEvent.click(within(dialog).getByRole("radio", { name: "Global" }));
+      const checkbox = within(dialog).getByRole("checkbox", { name: "Share JDT LS across builds" });
+      expect(checkbox).toBeChecked();
+      fireEvent.click(checkbox);
+      await act(async () => fireEvent.click(within(dialog).getByRole("button", { name: "Apply" })));
+      expect(settingsSet.mock.calls).toEqual([["global", "languages.java.jdtlsShared", "false"]]);
+    });
+
+    it("discards a shared JDT LS toggle on Cancel", async () => {
+      const dialog = await openDialog("languages.java");
+      fireEvent.click(within(dialog).getByRole("radio", { name: "This project" }));
+      fireEvent.click(within(dialog).getByRole("checkbox", { name: "Share JDT LS across builds" }));
+      fireEvent.click(within(dialog).getByRole("button", { name: "Cancel" }));
+      expect(settingsSet).not.toHaveBeenCalled();
+      expect(current.languages?.java?.jdtlsShared).toBe(false);
+    });
+
+    it("disables shared JDT LS only in a native Workspace's project scope", async () => {
+      useProject.setState((s) => ({
+        project: { ...s.project!, workspace: { version: 1, name: "Workspace", projects: ["/p/member"] } },
+      }));
+      const dialog = await openDialog("languages.java");
+      fireEvent.click(within(dialog).getByRole("radio", { name: "This project" }));
+      expect(within(dialog).getByRole("checkbox", { name: "Share JDT LS across builds" })).toBeDisabled();
+      expect(within(dialog).getByText(/Open a workspace member as a project/)).toBeInTheDocument();
+      fireEvent.click(within(dialog).getByRole("radio", { name: "Global" }));
+      const checkbox = within(dialog).getByRole("checkbox", { name: "Share JDT LS across builds" });
+      expect(checkbox).toBeEnabled();
+      fireEvent.click(checkbox);
+      await act(async () => fireEvent.click(within(dialog).getByRole("button", { name: "Apply" })));
+      expect(settingsSet.mock.calls).toEqual([["global", "languages.java.jdtlsShared", "true"]]);
+    });
+
+    it("disables sharing for a Java language server target only in project scope", async () => {
+      current = setAt(current, "languageServerTargets", { java: { target: "docker:java", server: "jdtls" } });
+      useProject.setState({ settings: current });
+      const dialog = await openDialog("languages.java");
+      fireEvent.click(within(dialog).getByRole("radio", { name: "This project" }));
+      const checkbox = within(dialog).getByRole("checkbox", { name: "Share JDT LS across builds" });
+      expect(checkbox).toBeDisabled();
+      expect(within(dialog).getByText(/Select Local machine for the Java language server/)).toBeInTheDocument();
+      fireEvent.click(within(dialog).getByRole("radio", { name: "Global" }));
+      expect(checkbox).toBeEnabled();
+      fireEvent.click(checkbox);
+      await act(async () => fireEvent.click(within(dialog).getByRole("button", { name: "Apply" })));
+      expect(settingsSet.mock.calls).toEqual([["global", "languages.java.jdtlsShared", "true"]]);
+    });
+
+    it.each([{ java: { target: "", server: "jdtls" } }, { python: { target: "docker:python" } }])(
+      "keeps sharing available when Java runs locally: %j",
+      async (targets) => {
+        current = setAt(current, "languageServerTargets", targets);
+        useProject.setState({ settings: current });
+        const dialog = await openDialog("languages.java");
+        fireEvent.click(within(dialog).getByRole("radio", { name: "This project" }));
+        expect(within(dialog).getByRole("checkbox", { name: "Share JDT LS across builds" })).toBeEnabled();
+      },
+    );
+
+    it("uses a staged project Java language server target before Apply", async () => {
+      const dialog = await openDialog("languages.java");
+      fireEvent.click(within(dialog).getByRole("radio", { name: "This project" }));
+      const checkbox = within(dialog).getByRole("checkbox", { name: "Share JDT LS across builds" });
+      expect(checkbox).toBeEnabled();
+      act(() => stage("languages.servers", "project", "languageServerTargets.java.target", "docker:java"));
+      expect(checkbox).toBeDisabled();
+      expect(settingsSet).not.toHaveBeenCalled();
+    });
+
     it("Settings for New Projects edits the global layer on every page", async () => {
       render(<SettingsDialog />);
       await act(async () => {

src/features/settings/__tests__/languages.test.ts

@@ -192,6 +192,15 @@ describe("languages settings", () => {
     expect(folderRole(ps, "src")).toBeNull();
   });
 
+  it("defaults shared JDT LS to off and accepts only boolean values", () => {
+    expect(DEFAULT_LANGUAGES.java.jdtlsShared).toBe(false);
+    expect(validateLanguages({}).java.jdtlsShared).toBe(false);
+    expect(validateSettings({ languages: { java: { jdtlsShared: true } } }).languages.java.jdtlsShared).toBe(true);
+    expect(validateLanguages({ java: { jdtlsShared: false } }).java.jdtlsShared).toBe(false);
+    for (const invalid of ["true", 1, null, []])
+      expect(validateLanguages({ java: { jdtlsShared: invalid } }).java.jdtlsShared).toBe(false);
+  });
+
   it("defaults Java language level to SDK default and keeps only supported levels", () => {
     expect(validateLanguages({}).java.languageLevel).toBe("");
     expect(validateLanguages({ java: { languageLevel: "8" } }).java.languageLevel).toBe("8");

src/features/settings/languages/LanguagePages.tsx

@@ -4,15 +4,16 @@
  * use (applied by `ide-sdk` when language servers start and when run configurations load).
  */
 import { LanguageServerTargetRows, LanguageServerTargetsPage } from "./LanguageServerTarget";
+import { useProject } from "@/platform/project";
 import { useRunTargets } from "@/platform/pluginRunTargets";
 import { tx } from "@/platform/i18n";
 import { useEffect, useId, useMemo, useState } from "react";
-import { call, commands, type Sdk } from "@/platform/ipc";
+import { call, commands, type LanguageServerTarget, type Sdk } from "@/platform/ipc";
 import { IconButton, Input, type SelectOption, T } from "@/ui";
 import { JAVA_LANGUAGE_LEVELS, PHP_LANGUAGE_LEVELS } from "@/platform/languageSettings";
 import { GlobListEditor, Row, Section, Select, Toggle } from "../components/Form";
 import { choosePath } from "./api";
-import { useSetting } from "../components/context";
+import { usePageContext, useSetting } from "../components/context";
 import { SdkField, tildify, useDetected } from "./components";
 import styles from "./Sdk.module.css";
 
@@ -387,6 +388,11 @@ export const JAVA_LEVEL_OPTIONS: SelectOption[] = JAVA_LANGUAGE_LEVELS.map((leve
 );
 
 export function JavaPage() {
+  const [shared, setShared] = useSetting<boolean>("languages.java.jdtlsShared");
+  const [serverTargets] = useSetting<Record<string, LanguageServerTarget>>("languageServerTargets", "project");
+  const { scope } = usePageContext();
+  const workspace = useProject((s) => !!s.project?.workspace);
+  const sharedDisabled = scope === "project" && (workspace || !!serverTargets?.java?.target);
   const [vmArgs, setVmArgs] = useSetting<string>("languages.java.jdtlsVmArgs");
   const [languageLevel, setLanguageLevel] = useSetting<string>("languages.java.languageLevel");
   const id = useId();
@@ -417,6 +423,19 @@ export function JavaPage() {
         </Row>
       </Section>
       <Section title="Language Server">
+        <Toggle
+          label="Share JDT LS across builds"
+          checked={shared}
+          onChange={setShared}
+          disabled={sharedDisabled}
+          hint={
+            sharedDisabled
+              ? workspace
+                ? "Shared JDT LS is available only in local ordinary project windows. Open a workspace member as a project to change this setting for it."
+                : "Shared JDT LS is available only in local ordinary project windows. Select Local machine for the Java language server to use it."
+              : "Uses one JDT LS process for linked builds in each local ordinary project window. Other project windows use separate processes."
+          }
+        />
         <SdkRow
           k="languages.java.jdtlsJdk"
           label="JDK"

src/features/settings/pages/languages.tsx

@@ -132,6 +132,9 @@ export const LANGUAGE_PAGES: PageSpec[] = [
       "lombok",
       "javaagent",
       "eclipse jdt",
+      "shared jdtls",
+      "linked builds",
+      "server process",
     ],
     component: JavaPage,
   },

src/platform/languageSettings.ts

@@ -164,6 +164,7 @@ export interface LanguagesValid {
     languageLevel: (typeof JAVA_LANGUAGE_LEVELS)[number];
     jdtlsJdk: string;
     jdtlsVmArgs: string;
+    jdtlsShared: boolean;
     gradle: {
       linkedProjects: string[] | null;
       jvm: string;
@@ -243,6 +244,7 @@ export const DEFAULT_LANGUAGES: LanguagesValid = {
     languageLevel: "",
     jdtlsJdk: "",
     jdtlsVmArgs: "",
+    jdtlsShared: false,
     gradle: { linkedProjects: null, jvm: "", distribution: "wrapper", home: "", userHome: "", runUsing: "gradle" },
     maven: {
       runnerJre: "",
@@ -401,6 +403,7 @@ export function validateLanguages(raw: unknown): LanguagesValid {
       languageLevel: oneOf(java.languageLevel, JAVA_LANGUAGE_LEVELS, d.java.languageLevel),
       jdtlsJdk: text(java.jdtlsJdk, d.java.jdtlsJdk),
       jdtlsVmArgs: text(java.jdtlsVmArgs, d.java.jdtlsVmArgs),
+      jdtlsShared: bool(java.jdtlsShared, d.java.jdtlsShared),
       gradle: {
         linkedProjects: Array.isArray(gradle.linkedProjects)
           ? gradle.linkedProjects.filter((p): p is string => typeof p === "string")

src/platform/locales/text/en.json

@@ -1,4 +1,8 @@
 {
+  "Shared JDT LS is available only in local ordinary project windows. Select Local machine for the Java language server to use it.": "Shared JDT LS is available only in local ordinary project windows. Select Local machine for the Java language server to use it.",
+  "Share JDT LS across builds": "Share JDT LS across builds",
+  "Shared JDT LS is available only in local ordinary project windows. Open a workspace member as a project to change this setting for it.": "Shared JDT LS is available only in local ordinary project windows. Open a workspace member as a project to change this setting for it.",
+  "Uses one JDT LS process for linked builds in each local ordinary project window. Other project windows use separate processes.": "Uses one JDT LS process for linked builds in each local ordinary project window. Other project windows use separate processes.",
   "Finder": "Finder",
   "Explorer": "Explorer",
   "Files": "Files",

src/platform/locales/text/zh.json

@@ -1,4 +1,8 @@
 {
+  "Shared JDT LS is available only in local ordinary project windows. Select Local machine for the Java language server to use it.": "共享 JDT LS 仅适用于本机的普通项目窗口。请将 Java 语言服务器的运行位置设为本机后再使用。",
+  "Share JDT LS across builds": "在构建间共享 JDT LS",
+  "Shared JDT LS is available only in local ordinary project windows. Open a workspace member as a project to change this setting for it.": "共享 JDT LS 仅适用于本机的普通项目窗口。请将工作区成员作为项目打开，再修改其此项设置。",
+  "Uses one JDT LS process for linked builds in each local ordinary project window. Other project windows use separate processes.": "在每个本机普通项目窗口中，已关联的构建共用一个 JDT LS 进程。其他项目窗口使用各自独立的进程。",
   "Finder": "访达",
   "Explorer": "资源管理器",
   "Reveal in Finder": "在访达中显示",