👍 add plugin unload feature

autoload/denops/_internal/plugin.vim

@@ -1,6 +1,7 @@
 const s:STATE_RESERVED = 'reserved'
 const s:STATE_LOADING = 'loading'
 const s:STATE_LOADED = 'loaded'
+const s:STATE_UNLOADING = 'unloading'
 const s:STATE_FAILED = 'failed'
 
 let s:plugins = {}
@@ -27,6 +28,14 @@ function! denops#_internal#plugin#load(name, script) abort
   call denops#_internal#server#chan#notify('invoke', ['load', l:args])
 endfunction
 
+function! denops#_internal#plugin#unload(name) abort
+  let l:args = [a:name]
+  let l:plugin = denops#_internal#plugin#get(a:name)
+  let l:plugin.state = s:STATE_UNLOADING
+  call denops#_internal#echo#debug(printf('unload plugin: %s', l:args))
+  call denops#_internal#server#chan#notify('invoke', ['unload', l:args])
+endfunction
+
 function! denops#_internal#plugin#reload(name) abort
   const l:args = [a:name]
   let l:plugin = denops#_internal#plugin#get(a:name)
@@ -60,10 +69,36 @@ function! s:DenopsSystemPluginFail() abort
   execute printf('doautocmd <nomodeline> User DenopsPluginFail:%s', l:name)
 endfunction
 
+function! s:DenopsSystemPluginUnloadPre() abort
+  const l:name = matchstr(expand('<amatch>'), 'DenopsSystemPluginUnloadPre:\zs.*')
+  let l:plugin = denops#_internal#plugin#get(l:name)
+  let l:plugin.state = s:STATE_UNLOADING
+  execute printf('doautocmd <nomodeline> User DenopsPluginUnloadPre:%s', l:name)
+endfunction
+
+function! s:DenopsSystemPluginUnloadPost() abort
+  const l:name = matchstr(expand('<amatch>'), 'DenopsSystemPluginUnloadPost:\zs.*')
+  let l:plugin = denops#_internal#plugin#get(l:name)
+  let l:plugin.state = s:STATE_RESERVED
+  let l:plugin.callbacks = []
+  execute printf('doautocmd <nomodeline> User DenopsPluginUnloadPost:%s', l:name)
+endfunction
+
+function! s:DenopsSystemPluginUnloadFail() abort
+  const l:name = matchstr(expand('<amatch>'), 'DenopsSystemPluginUnloadFail:\zs.*')
+  let l:plugin = denops#_internal#plugin#get(l:name)
+  let l:plugin.state = s:STATE_FAILED
+  let l:plugin.callbacks = []
+  execute printf('doautocmd <nomodeline> User DenopsPluginUnloadFail:%s', l:name)
+endfunction
+
 augroup denops_autoload_plugin_internal
   autocmd!
   autocmd User DenopsSystemPluginPre:* ++nested call s:DenopsSystemPluginPre()
   autocmd User DenopsSystemPluginPost:* ++nested call s:DenopsSystemPluginPost()
   autocmd User DenopsSystemPluginFail:* ++nested call s:DenopsSystemPluginFail()
+  autocmd User DenopsSystemPluginUnloadPre:* ++nested call s:DenopsSystemPluginUnloadPre()
+  autocmd User DenopsSystemPluginUnloadPost:* ++nested call s:DenopsSystemPluginUnloadPost()
+  autocmd User DenopsSystemPluginUnloadFail:* ++nested call s:DenopsSystemPluginUnloadFail()
   autocmd User DenopsClosed let s:plugins = {}
 augroup END

autoload/denops/plugin.vim

@@ -53,6 +53,10 @@ function! denops#plugin#load(name, script) abort
   call denops#_internal#plugin#load(a:name, a:script)
 endfunction
 
+function! denops#plugin#unload(name) abort
+  call denops#_internal#plugin#unload(a:name)
+endfunction
+
 function! denops#plugin#reload(name) abort
   call denops#_internal#plugin#reload(a:name)
 endfunction

deno.jsonc

@@ -7,6 +7,12 @@
     "update": "deno run --allow-env --allow-read --allow-write=. --allow-run=git,deno --allow-net=jsr.io,registry.npmjs.org jsr:@molt/cli **/*.ts",
     "update:commit": "deno task -q update --commit --pre-commit=fmt,lint"
   },
+  "test": {
+    "exclude": [
+      // TODO: #349 Update `Entrypoint` in denops-core, and remove this entry.
+      "denops/@denops-private/plugin.ts"
+    ]
+  },
   "exclude": [
     ".coverage/"
   ],

denops/@denops-private/host.ts

@@ -49,6 +49,7 @@ export type CallbackId = string;
 export type Service = {
   bind(host: Host): void;
   load(name: string, script: string): Promise<void>;
+  unload(name: string): Promise<void>;
   reload(name: string): Promise<void>;
   interrupt(reason?: unknown): void;
   dispatch(name: string, fn: string, args: unknown[]): Promise<unknown>;
@@ -72,6 +73,8 @@ export function invoke(
   switch (name) {
     case "load":
       return service.load(...ensure(args, serviceMethodArgs.load));
+    case "unload":
+      return service.unload(...ensure(args, serviceMethodArgs.unload));
     case "reload":
       return service.reload(...ensure(args, serviceMethodArgs.reload));
     case "interrupt":
@@ -92,6 +95,7 @@ export function invoke(
 
 const serviceMethodArgs = {
   load: is.ParametersOf([is.String, is.String] as const),
+  unload: is.ParametersOf([is.String] as const),
   reload: is.ParametersOf([is.String] as const),
   interrupt: is.ParametersOf([is.OptionalOf(is.Unknown)] as const),
   dispatch: is.ParametersOf([is.String, is.String, is.Array] as const),

denops/@denops-private/host/nvim_test.ts

@@ -23,6 +23,7 @@ Deno.test("Neovim", async (t) => {
       const service: Service = {
         bind: () => unimplemented(),
         load: () => unimplemented(),
+        unload: () => unimplemented(),
         reload: () => unimplemented(),
         interrupt: () => unimplemented(),
         dispatch: () => unimplemented(),

denops/@denops-private/host/vim_test.ts

@@ -18,6 +18,7 @@ Deno.test("Vim", async (t) => {
       const service: Service = {
         bind: () => unimplemented(),
         load: () => unimplemented(),
+        unload: () => unimplemented(),
         reload: () => unimplemented(),
         interrupt: () => unimplemented(),
         dispatch: () => unimplemented(),

denops/@denops-private/host_test.ts

@@ -11,6 +11,7 @@ import { invoke, type Service } from "./host.ts";
 Deno.test("invoke", async (t) => {
   const service: Omit<Service, "bind"> = {
     load: () => unimplemented(),
+    unload: () => unimplemented(),
     reload: () => unimplemented(),
     interrupt: () => unimplemented(),
     dispatch: () => unimplemented(),

denops/@denops-private/plugin.ts

@@ -0,0 +1,35 @@
+// TODO: #349 Update `Entrypoint` in denops-core, remove this module from `$.test.exclude` in `deno.jsonc`, and remove this module.
+import type { Denops } from "jsr:@denops/[email protected]";
+
+/**
+ * Denops's entrypoint definition.
+ *
+ * Use this type to ensure the `main` function is properly implemented like:
+ *
+ * ```ts
+ * import type { Entrypoint } from "jsr:@denops/core";
+ *
+ * export const main: Entrypoint = (denops) => {
+ *   // ...
+ * }
+ * ```
+ *
+ * If an `AsyncDisposable` object is returned, resources can be disposed of
+ * asynchronously when the plugin is unloaded, like:
+ *
+ * ```ts
+ * import type { Entrypoint } from "jsr:@denops/core";
+ *
+ * export const main: Entrypoint = (denops) => {
+ *   // ...
+ *   return {
+ *     [Symbol.asyncDispose]: () => {
+ *       // Dispose resources...
+ *     }
+ *   }
+ * }
+ * ```
+ */
+export type Entrypoint = (
+  denops: Denops,
+) => void | AsyncDisposable | Promise<void | AsyncDisposable>;

denops/@denops-private/service.ts

@@ -1,3 +1,6 @@
+// TODO: #349 Import `Entrypoint` from denops-core.
+// import type { Entrypoint } from "jsr:@denops/[email protected]";
+import type { Entrypoint } from "./plugin.ts";
 import type { Denops, Meta } from "jsr:@denops/[email protected]";
 import { toFileUrl } from "jsr:@std/[email protected]/to-file-url";
 import { toErrorObject } from "jsr:@lambdalisue/[email protected]";
@@ -38,11 +41,7 @@ export class Service implements HostService, AsyncDisposable {
     this.#host = host;
   }
 
-  async load(
-    name: string,
-    script: string,
-    suffix = "",
-  ): Promise<void> {
+  async load(name: string, script: string): Promise<void> {
     if (this.#closed) {
       throw new Error("Service closed");
     }
@@ -58,26 +57,36 @@ export class Service implements HostService, AsyncDisposable {
     const denops = new DenopsImpl(name, this.#meta, this.#host, this);
     const plugin = new Plugin(denops, name, script);
     this.#plugins.set(name, plugin);
-    await plugin.load(suffix);
-    this.#getWaiter(name).resolve();
+    try {
+      await plugin.waitLoaded();
+      this.#getWaiter(name).resolve();
+    } catch {
+      this.#plugins.delete(name);
+    }
   }
 
-  reload(
-    name: string,
-  ): Promise<void> {
+  async #unload(name: string): Promise<Plugin | undefined> {
     const plugin = this.#plugins.get(name);
     if (!plugin) {
       if (this.#meta.mode === "debug") {
         console.log(`A denops plugin '${name}' is not loaded yet. Skip`);
       }
-      return Promise.resolve();
+      return;
     }
     this.#plugins.delete(name);
-    this.#waiters.delete(name);
-    // Import module with fragment so that reload works properly
-    // https://github.com/vim-denops/denops.vim/issues/227
-    const suffix = `#${performance.now()}`;
-    return this.load(name, plugin.script, suffix);
+    await plugin.unload();
+    return plugin;
+  }
+
+  async unload(name: string): Promise<void> {
+    await this.#unload(name);
+  }
+
+  async reload(name: string): Promise<void> {
+    const plugin = await this.#unload(name);
+    if (plugin) {
+      await this.load(name, plugin.script);
+    }
   }
 
   waitLoaded(name: string): Promise<void> {
@@ -137,14 +146,17 @@ export class Service implements HostService, AsyncDisposable {
     }
   }
 
-  close(): Promise<void> {
+  async close(): Promise<void> {
     if (!this.#closed) {
       this.#closed = true;
       const error = new Error("Service closed");
       for (const { reject } of this.#waiters.values()) {
         reject(error);
       }
       this.#waiters.clear();
+      await Promise.all(
+        [...this.#plugins.values()].map((plugin) => plugin.unload()),
+      );
       this.#plugins.clear();
       this.#host = undefined;
       this.#closedWaiter.resolve();
@@ -161,8 +173,14 @@ export class Service implements HostService, AsyncDisposable {
   }
 }
 
+type PluginModule = {
+  main: Entrypoint;
+};
+
 class Plugin {
   #denops: Denops;
+  #loadedWaiter: Promise<void>;
+  #disposable: Partial<AsyncDisposable> = {};
 
   readonly name: string;
   readonly script: string;
@@ -171,13 +189,19 @@ class Plugin {
     this.#denops = denops;
     this.name = name;
     this.script = resolveScriptUrl(script);
+    this.#loadedWaiter = this.#load();
   }
 
-  async load(suffix = ""): Promise<void> {
+  waitLoaded(): Promise<void> {
+    return this.#loadedWaiter;
+  }
+
+  async #load(): Promise<void> {
+    const suffix = createScriptSuffix(this.script);
     try {
       await emit(this.#denops, `DenopsSystemPluginPre:${this.name}`);
-      const mod = await import(`${this.script}${suffix}`);
-      await mod.main(this.#denops);
+      const mod: PluginModule = await import(`${this.script}${suffix}`);
+      this.#disposable = await mod.main(this.#denops) ?? {};
       await emit(this.#denops, `DenopsSystemPluginPost:${this.name}`);
     } catch (e) {
       // Show a warning message when Deno module cache issue is detected
@@ -195,6 +219,27 @@ class Plugin {
       }
       console.error(`Failed to load plugin '${this.name}': ${e}`);
       await emit(this.#denops, `DenopsSystemPluginFail:${this.name}`);
+      throw e;
+    }
+  }
+
+  async unload(): Promise<void> {
+    try {
+      // Wait for the load to complete to make the events atomically.
+      await this.#loadedWaiter;
+    } catch {
+      // Load failed, do nothing
+      return;
+    }
+    try {
+      await emit(this.#denops, `DenopsSystemPluginUnloadPre:${this.name}`);
+      await this.#disposable[Symbol.asyncDispose]?.();
+      await emit(this.#denops, `DenopsSystemPluginUnloadPost:${this.name}`);
+    } catch (e) {
+      console.error(`Failed to unload plugin '${this.name}': ${e}`);
+      await emit(this.#denops, `DenopsSystemPluginUnloadFail:${this.name}`);
+    } finally {
+      this.#disposable = {};
     }
   }
 
@@ -210,6 +255,16 @@ class Plugin {
   }
 }
 
+const loadedScripts = new Set<string>();
+
+function createScriptSuffix(script: string): string {
+  // Import module with fragment so that reload works properly
+  // https://github.com/vim-denops/denops.vim/issues/227
+  const suffix = loadedScripts.has(script) ? `#${performance.now()}` : "";
+  loadedScripts.add(script);
+  return suffix;
+}
+
 async function emit(denops: Denops, name: string): Promise<void> {
   try {
     await denops.cmd(`doautocmd <nomodeline> User ${name}`);