file watchers now work and force recompilation correctly

rtsc/compile-all.ts

@@ -1,4 +1,4 @@
-import { FSWatcher, watch } from "node:fs";
+import { watch } from "node:fs";
 import fs from "node:fs/promises";
 import process from "node:process";
 import path, { basename, dirname, join } from "node:path";
@@ -11,9 +11,27 @@ import { parse } from "../src/parse.ts";
 import { assert } from "../src/assert.ts";
 
 class DirWatcher {
-  private fswatcher: FSWatcher;
-  constructor(fswatcher: FSWatcher) {
-    this.fswatcher = fswatcher;
+  private dir: string;
+  private callbacks: { [filename: string]: (path: string) => void } = {};
+  public onEvent: ((file: string) => void) | undefined = undefined;
+  constructor(dir: string) {
+    this.dir = dir;
+  }
+  watchFile(path: string, callback: (path: string) => void): { close(): void } {
+    assert(dirname(path) === this.dir);
+    const filename = basename(path);
+    assert(!this.callbacks[filename], `multiple watches for same path '${path}'`);
+    this.callbacks[filename] = callback;
+    return {
+      close() {
+        throw new Error(`close is not yet done`);
+      },
+    };
+  }
+  processEvent(event: "rename" | "change", file: string) {
+    this.onEvent?.(file);
+    const callback = this.callbacks[file];
+    if (callback) callback(join(this.dir, file));
   }
 }
 
@@ -25,6 +43,24 @@ class WatchFS {
     this.init();
   }
 
+  watchFile(path: string, callback: (path: string) => void): { close(): void } {
+    const dir = dirname(path);
+    const watcher = this.get_or_create_watcher(dir);
+    return watcher.watchFile(path, callback);
+  }
+
+  private get_or_create_watcher(abspath: string): DirWatcher {
+    const existing = this.dir_watchers[abspath];
+    if (existing) return existing;
+    const fswatcher = watch(abspath, { encoding: "utf8", recursive: false }, (event, file) => {
+      assert(file !== null);
+      watcher.processEvent(event, file);
+    });
+    const watcher = new DirWatcher(abspath);
+    this.dir_watchers[abspath] = watcher;
+    return watcher;
+  }
+
   private async init() {
     const gitignore_content = await fs.readFile(".gitignore", { encoding: "utf8" });
     const ig = ignore().add(gitignore_content).add("/.git");
@@ -57,11 +93,9 @@ class WatchFS {
     };
 
     const seed_dir = async (relpath: string, abspath: string) => {
-      const fswatcher = watch(abspath, { encoding: "utf8", recursive: false }, (event, file) => {
-        console.log(`watch ${event} ${file} in ${abspath}`);
-        if (file !== null) check_file(file, relpath, abspath);
-      });
-      this.dir_watchers[abspath] = new DirWatcher(fswatcher);
+      const watcher = this.get_or_create_watcher(abspath);
+      assert(!watcher.onEvent);
+      watcher.onEvent = (file) => check_file(file, relpath, abspath);
       fs.readdir(relpath).then((files) =>
         files.forEach((file) => check_file(file, relpath, abspath)),
       );
@@ -75,10 +109,7 @@ const globals = get_globals("es2024.full");
 const patterns = core_patterns(parse);
 const library_manager = new LibraryManager(patterns, globals, ["es2024.full"], {
   watchFile(path, callback) {
-    const watcher = {
-      close() {},
-    };
-    return watcher;
+    return FS.watchFile(path, callback);
   },
 });
 

src/library-manager.ts

@@ -191,8 +191,8 @@ abstract class Module implements imported_module {
       (x) => (x.dependant_modules = x.dependant_modules.filter((x) => x !== this)),
     );
     this.imported_modules = [];
-    dependant_modules.forEach((x) => x.force_recompile());
-    this.ensureUpToDate();
+    await Promise.all(dependant_modules.map((x) => x.force_recompile()));
+    await this.ensureUpToDate();
   }
 
   async file_changed(): Promise<void> {
@@ -202,7 +202,7 @@ abstract class Module implements imported_module {
     switch (state.type) {
       case "fresh": {
         if (t && t > state.mtime) {
-          this.force_recompile();
+          await this.force_recompile();
         }
         return;
       }