fix(editor): show usage counts when the project finishes loading at launch (#1809)

Usage counts asked while a language server loads the project come back incomplete and were re-asked only after a busy spell of 1.5 s or more, seen from the editor's own mount. An editor restored at launch mounts while its server starts, so it missed the spell's start, and a short load (vtsls loads a small project in about a second) never counted. Server spells are now followed once from app start, and the spell right after a start counts as loading whatever its length; later short spells are still ignored so request progress (jdtls) doesn't loop. The implementations gutter shares the same settle signal.

Co-authored-by: jaw52 <[email protected]>

src/editor/lsp/availability.test.ts

@@ -16,46 +16,95 @@ vi.mock("@/platform/ipc", async (orig) => {
 
 const { onServerSettled, featureBackoff, installAvailabilityEvents } = await import("./availability");
 
-const status = (s: string) => {
-  for (const fn of listeners) fn({ type: "languageServer", server: 1, status: s } as unknown as IdeEvent);
+const status = (s: string, server = 1) => {
+  for (const fn of [...listeners]) fn({ type: "languageServer", server, status: s } as unknown as IdeEvent);
 };
 
 describe("onServerSettled", () => {
+  // Spells are followed once for the whole app: each test uses its own server.
+  const offs: (() => void)[] = [];
+  const settled = (fn: () => void) => offs.push(onServerSettled(fn));
   afterEach(() => {
     vi.useRealTimers();
-    listeners.clear();
+    for (const off of offs.splice(0)) off();
   });
 
   it("re-runs a callback that keeps the server busy only once", () => {
     vi.useFakeTimers();
     const fn = vi.fn();
-    onServerSettled(fn);
-    status("starting");
-    status("ready");
+    settled(fn);
+    status("starting", 1);
+    status("ready", 1);
     expect(fn).toHaveBeenCalledTimes(1);
     for (let i = 0; i < 2; i++) {
-      status("busy");
+      status("busy", 1);
       vi.advanceTimersByTime(2000);
-      status("ready");
+      status("ready", 1);
     }
     expect(fn).toHaveBeenCalledTimes(2);
     // Indexing that starts later is a new settle.
     vi.advanceTimersByTime(10_000);
-    status("busy");
+    status("busy", 1);
     vi.advanceTimersByTime(5000);
-    status("ready");
+    status("ready", 1);
     expect(fn).toHaveBeenCalledTimes(3);
   });
 
   it("ignores short busy spells", () => {
     vi.useFakeTimers();
     const fn = vi.fn();
-    onServerSettled(fn);
-    status("busy");
+    settled(fn);
+    status("busy", 2);
     vi.advanceTimersByTime(100);
-    status("ready");
+    status("ready", 2);
     expect(fn).not.toHaveBeenCalled();
   });
+
+  it("re-runs after the project loads right after a start, however briefly", () => {
+    vi.useFakeTimers();
+    const fn = vi.fn();
+    settled(fn);
+    status("starting", 3);
+    status("ready", 3);
+    expect(fn).toHaveBeenCalledTimes(1);
+    // vtsls loads a small project in about a second; answers given meanwhile were partial.
+    status("busy", 3);
+    vi.advanceTimersByTime(1000);
+    status("ready", 3);
+    expect(fn).toHaveBeenCalledTimes(2);
+    // Later short spells are requests again.
+    status("busy", 3);
+    vi.advanceTimersByTime(100);
+    status("ready", 3);
+    expect(fn).toHaveBeenCalledTimes(2);
+  });
+
+  it("tells a callback added while the project loads that it has", () => {
+    vi.useFakeTimers();
+    settled(() => {});
+    status("starting", 4);
+    status("ready", 4);
+    status("busy", 4);
+    // An editor restored at launch mounts now.
+    const fn = vi.fn();
+    settled(fn);
+    vi.advanceTimersByTime(800);
+    status("ready", 4);
+    expect(fn).toHaveBeenCalledTimes(1);
+  });
+
+  it("ignores a short spell that begins well after a start", () => {
+    vi.useFakeTimers();
+    const fn = vi.fn();
+    settled(fn);
+    status("starting", 5);
+    status("ready", 5);
+    vi.advanceTimersByTime(10_000);
+    status("busy", 5);
+    vi.advanceTimersByTime(100);
+    status("ready", 5);
+    expect(fn).toHaveBeenCalledTimes(1);
+  });
 });
 
 describe("featureBackoff", () => {

src/editor/lsp/availability.ts

@@ -68,38 +68,81 @@ const LONG_BUSY_MS = 1500;
 /** A busy spell starting this soon after `fn` ran may be `fn`'s own requests. */
 const ECHO_MS = 2000;
 
+/** A busy spell starting this soon after a start is the server loading the project. */
+const LOADING_AFTER_START_MS = 5000;
+
+type Settle = (server: number, spellStart: number, loading: boolean) => void;
+
+/** Servers starting (`-Infinity`) or busy since when. */
+const spells = new Map<number, number>();
+/** When servers became ready after starting, until their next spell ends. */
+const readyAfterStart = new Map<number, number>();
+const settles = new Set<Settle>();
+let tracking = false;
+
+/**
+ * Follows every server's spells from app start, so an editor that mounts while its
+ * server starts or loads (one restored at launch) still learns when that ends.
+ */
+function trackSpells() {
+  if (tracking || !isTauri()) return;
+  tracking = true;
+  onIdeEvent("languageServer", (e) => {
+    if (e.status === "starting") {
+      spells.set(e.server, -Infinity);
+      readyAfterStart.delete(e.server);
+    } else if (e.status === "busy") {
+      if (!spells.has(e.server)) spells.set(e.server, Date.now());
+    } else if (e.status === "ready") {
+      const t = spells.get(e.server);
+      spells.delete(e.server);
+      if (t === undefined) return;
+      const startedAt = readyAfterStart.get(e.server);
+      if (t === -Infinity) readyAfterStart.set(e.server, Date.now());
+      else readyAfterStart.delete(e.server);
+      const loading = startedAt !== undefined && t - startedAt < LOADING_AFTER_START_MS;
+      for (const settle of settles) settle(e.server, t, loading);
+    } else {
+      spells.delete(e.server);
+      readyAfterStart.delete(e.server);
+    }
+  });
+}
+
 /**
  * Calls `fn` when a server becomes ready after starting or after a long busy
  * spell (indexing), when earlier answers may have been incomplete. Short busy
  * spells are ignored: jdtls reports progress for the very requests a caller
  * sends, and re-asking on each of them would never stop. For the same reason
  * a long spell that began right after `fn` ran (slow requests `fn` sent, or
- * indexing right after start) re-runs it only once in a row.
+ * indexing right after start) re-runs it only once in a row. The spell right
+ * after a start counts whatever its length: it is the project loading (vtsls
+ * loads a small one in about a second), and answers given meanwhile are partial.
  */
 export function onServerSettled(fn: () => void): () => void {
   if (!isTauri()) return () => {};
-  const since = new Map<number, number>();
+  trackSpells();
   const fired = new Map<number, { at: number; echoed: boolean }>();
-  return onIdeEvent("languageServer", (e) => {
-    if (e.status === "starting") {
-      since.set(e.server, -Infinity);
-      fired.delete(e.server);
-    } else if (e.status === "busy") {
-      if (!since.has(e.server)) since.set(e.server, Date.now());
-    } else if (e.status === "ready") {
-      const t = since.get(e.server);
-      since.delete(e.server);
-      if (t === undefined || Date.now() - t < LONG_BUSY_MS) return;
-      const last = fired.get(e.server);
-      const echo = !!last && t - last.at < ECHO_MS;
-      if (echo && last.echoed) return;
-      fired.set(e.server, { at: Date.now(), echoed: echo });
-      fn();
-    } else since.delete(e.server);
+  const settle: Settle = (server, t, loading) => {
+    if (!loading && Date.now() - t < LONG_BUSY_MS) return;
+    const last = fired.get(server);
+    const echo = !!last && t - last.at < ECHO_MS;
+    if (echo && last.echoed) return;
+    fired.set(server, { at: Date.now(), echoed: echo });
+    fn();
+  };
+  settles.add(settle);
+  const offStarting = onIdeEvent("languageServer", (e) => {
+    if (e.status === "starting") fired.delete(e.server);
   });
+  return () => {
+    settles.delete(settle);
+    offStarting();
+  };
 }
 
 export function installAvailabilityEvents(): () => void {
+  trackSpells();
   return onIdeEvent("languageServer", (e) => {
     if (e.status === "ready") clearBackoffs();
   });