feat(csharp): navigate to decompiled assembly definitions (#1689)

src/editor/core/backend.ts

@@ -126,6 +126,7 @@ const EXT_LANG: Record<string, string> = {
   kt: "kotlin",
   kts: "kotlin",
   java: "java",
+  cs: "csharp",
   py: "python",
   gd: "gdscript",
   go: "go",

src/editor/core/view/Banner.tsx

@@ -43,7 +43,11 @@ export function VirtualBanner({
     <div className={`${styles.banner} ${styles.libraryBanner}`} role="status">
       <Icon name={decompiled ? "info" : "lock"} size={14} className={styles.bannerIcon} />
       <span className={styles.virtualBannerText}>
-        {decompiled ? tx("Decompiled .class file: sources are not available.") : tx("Library source (read-only).")}
+        {decompiled
+          ? path.startsWith("csharp:")
+            ? tx("Decompiled assembly (read-only).")
+            : tx("Decompiled .class file: sources are not available.")
+          : tx("Library source (read-only).")}
         {reason && ` ${tx(reason)}`}
       </span>
       {description && (

src/editor/core/view/banner.test.tsx

@@ -2,9 +2,19 @@ import { describe, expect, it } from "vitest";
 import { act, render, screen } from "@testing-library/react";
 import { registerEditorBanner } from "@/workbench/contributions";
 import { useDocMeta, type DocMeta } from "../model/document";
-import { documentBanner, EditorBanners } from "./Banner";
+import { documentBanner, EditorBanners, VirtualBanner } from "./Banner";
 
 describe("editor banners", () => {
+  it.each([
+    ["jdt://contents/lib.jar/p/Lib.class", true, "Decompiled .class file: sources are not available."],
+    ["csharp:/p/App.csproj/decompiled/Lib.cs", true, "Decompiled assembly (read-only)."],
+    ["csharp:/p/App.csproj/generated/Lib.g.cs", false, "Library source (read-only)."],
+  ])("describes %s", (path, decompiled, text) => {
+    render(<VirtualBanner path={path} decompiled={decompiled} description="Example.Library" />);
+    expect(screen.getByRole("status").textContent).toContain(text);
+    expect(screen.getByTitle("Example.Library")).toBeTruthy();
+  });
+
   it("shows the document notice through the banner extension point, before contributed ones", () => {
     const off = [
       registerEditorBanner(documentBanner),

src/editor/core/virtual.test.ts

@@ -4,12 +4,23 @@ import type { VirtualDocument } from "@/platform/ipc";
 const JDT = "jdt://contents/lib-1.0.jar/org.example/Lib.class?=demo/%5C/m2%5C/lib-1.0.jar%3Corg.example%28Lib.class";
 const TEXT =
   "// Source code is unavailable, and was generated by the Fernflower decompiler.\npackage org.example;\n\npublic class Lib {\n  void run() {}\n}\n";
+const CSHARP = "csharp:/D:/My%20Game/Game.csproj/decompiled/UnityEngine.MonoBehaviour.cs";
+const CSHARP_TEXT = "namespace UnityEngine;\npublic class MonoBehaviour {\n    public void CancelInvoke() {}\n}\n";
 
 vi.mock("@/platform/virtualDocs", async (importOriginal) => {
   const actual = await importOriginal<typeof import("@/platform/virtualDocs")>();
   return {
     ...actual,
     virtualDocument: vi.fn(async (uri: string): Promise<VirtualDocument> => {
+      if (uri === CSHARP)
+        return {
+          uri,
+          text: CSHARP_TEXT,
+          languageId: "csharp",
+          title: "UnityEngine.MonoBehaviour.cs",
+          description: "UnityEngine.CoreModule",
+          decompiled: true,
+        };
       if (uri !== JDT && uri !== "file:///p/target/classes/Lib.class") throw new Error(`no contents for ${uri}`);
       return {
         uri,
@@ -128,10 +139,56 @@ describe("virtual editor input", () => {
     }
   });
 
-  it("does not open a tab when the server has no contents", async () => {
-    ctrl = new EditorController(createMemoryBackend());
+  it("navigates C# types and members in one read-only assembly tab", async () => {
+    const backend = createMemoryBackend({ "/p/Player.cs": "class Player {}\n", [CSHARP]: CSHARP_TEXT });
+    const save = vi.spyOn(backend, "save");
+    ctrl = new EditorController(backend);
     ctrl.start();
-    await ctrl.openFile("jdt://contents/missing.jar/p/X.class", { focus: false });
-    expect(Object.values(useTabs.getState().panes).flatMap((p) => p.tabs)).toHaveLength(0);
+    await ctrl.openFile("/p/Player.cs", { focus: false });
+    await ctrl.openFile(CSHARP, { selection: { line: 1, col: 13, endLine: 1, endCol: 26 }, focus: false });
+    const tab = activeTab();
+    const slot = ctrl.slotFor(tab.id)!;
+    expect(tab.input).toMatchObject({
+      kind: "virtual",
+      path: CSHARP,
+      data: { title: "UnityEngine.MonoBehaviour.cs", description: "UnityEngine.CoreModule", decompiled: true },
+    });
+    expect(slot.model.ctx()).toMatchObject({ language: "csharp", readOnly: true, virtual: true });
+    const selected = () => {
+      const state = slot.currentState();
+      return state.sliceDoc(state.selection.main.from, state.selection.main.to);
+    };
+    expect(selected()).toBe("MonoBehaviour");
+    await ctrl.openFile(CSHARP, { selection: { line: 2, col: 16, endLine: 2, endCol: 28 }, focus: false });
+    expect(activeTab().id).toBe(tab.id);
+    expect(selected()).toBe("CancelInvoke");
+    expect(Object.values(useTabs.getState().panes).flatMap((p) => p.tabs)).toHaveLength(2);
+    const doc = [...backend.docs.values()].find((d) => d.path === CSHARP)!;
+    await expect(backend.edit(doc.id, doc.version, [{ from: 0, to: 0, insert: "x" }])).rejects.toMatchObject({
+      kind: "permissionDenied",
+    });
+    await slot.model.save("explicit");
+    expect(save).not.toHaveBeenCalled();
+    expect((await backend.snapshot(doc.id)).text).toBe(CSHARP_TEXT);
+    await ctrl.back();
+    expect(activeTab().input.path).toBe(CSHARP);
+    expect(slot.currentState().selection.main.head).toBe(slot.currentState().doc.line(2).from + 13);
+    await ctrl.back();
+    expect(activeTab().input.path).toBe("/p/Player.cs");
+    await ctrl.forward();
+    expect(activeTab().input.path).toBe(CSHARP);
+    await ctrl.forward();
+    expect(slot.currentState().selection.main.head).toBe(slot.currentState().doc.line(3).from + 16);
+    expect(JSON.stringify(serializeSession(useTabs.getState(), {}))).not.toContain("csharp:");
   });
+
+  it.each(["jdt://contents/missing.jar/p/X.class", "csharp:/p/App.csproj/decompiled/Missing.cs"])(
+    "does not open a tab when the server has no contents for %s",
+    async (uri) => {
+      ctrl = new EditorController(createMemoryBackend());
+      ctrl.start();
+      await ctrl.openFile(uri, { focus: false });
+      expect(Object.values(useTabs.getState().panes).flatMap((p) => p.tabs)).toHaveLength(0);
+    },
+  );
 });

src/platform/locales/text/en.json

@@ -1,5 +1,6 @@
 {
   "Cannot copy reference": "Cannot copy reference",
+  "Decompiled assembly (read-only).": "Decompiled assembly (read-only).",
   "Connect through:": "Connect through:",
   "Connect through": "Connect through",
   "GitHub Commit Checks": "GitHub Commit Checks",

src/platform/locales/text/zh.json

@@ -4715,6 +4715,7 @@
   "Vim rc file": "Vim rc 文件",
   "Breakpoints are not supported in output classes without source code.": "输出目录中无源码的类不支持断点。",
   "Decompiled .class file: sources are not available.": "已反编译的 .class 文件：没有可用的源代码。",
+  "Decompiled assembly (read-only).": "已反编译的程序集（只读）。",
   "No column of the file matches the table": "文件中没有与该表匹配的列",
   "Not a URL of PostgreSQL, MySQL, SQLite or a compatible database": "不是 PostgreSQL、MySQL、SQLite 或兼容数据库的 URL",
   "The Database tree shows only the checked names and patterns (* and ?); the connected database always shows.": "数据库树只显示选中的名称和模式（* 和 ?）；已连接的数据库始终显示。",