fix: stop the dev runner rebuilding plugins when windows reports file reads as changes

scripts/dev-runner.test.ts

@@ -7,6 +7,7 @@ import {
   createSerialQueue,
   dataDirFor,
   findBuildablePlugins,
+  isPluginEdit,
   isPluginSourceChange,
   needsDocker,
   parseDevArgs,
@@ -46,6 +47,34 @@ describe("isPluginSourceChange", () => {
   });
 });
 
+describe("isPluginEdit", () => {
+  function repo() {
+    const dir = fs.mkdtempSync(path.join(os.tmpdir(), "termix-edit-"));
+    cleanups.push(() => fs.rmSync(dir, { recursive: true, force: true }));
+    fs.mkdirSync(path.join(dir, "src", "frontend"), { recursive: true });
+    fs.writeFileSync(path.join(dir, "src", "frontend", "index.ts"), "");
+    return dir;
+  }
+
+  it("ignores a folder being read", () => {
+    expect(isPluginEdit(repo(), "src/frontend", () => true)).toBe(false);
+  });
+
+  it("rebuilds an edited file only while the build is out of date", () => {
+    const dir = repo();
+    expect(isPluginEdit(dir, "src/frontend/index.ts", () => true)).toBe(true);
+    expect(isPluginEdit(dir, "src/frontend/index.ts", () => false)).toBe(false);
+  });
+
+  it("rebuilds after a source file is deleted", () => {
+    expect(isPluginEdit(repo(), "src/gone.ts", () => false)).toBe(true);
+  });
+
+  it("skips paths that do not feed the build", () => {
+    expect(isPluginEdit(repo(), "dist/index.js", () => true)).toBe(false);
+  });
+});
+
 describe("findBuildablePlugins", () => {
   it("lists repos with a manifest and installed dependencies", () => {
     const dir = fs.mkdtempSync(path.join(os.tmpdir(), "termix-dev-"));

scripts/dev.mjs

@@ -29,7 +29,7 @@ import {
   createSerialQueue,
   dataDirFor,
   findBuildablePlugins,
-  isPluginSourceChange,
+  isPluginEdit,
   needsDocker,
   parseDevArgs,
   parseTscStatus,
@@ -575,7 +575,7 @@ function watchPlugins(dir) {
   );
   for (const plugin of plugins) {
     watch(plugin.repo, true, (_event, filename) => {
-      if (isPluginSourceChange(filename)) changed(plugin.id);
+      if (isPluginEdit(plugin.repo, filename)) changed(plugin.id);
     });
   }
   log(`watching ${plugins.length} plugin(s) in ${dir}`);

scripts/lib/dev-runner.mjs

@@ -1,5 +1,10 @@
 import fs from "node:fs";
 import path from "node:path";
+import { createRequire } from "node:module";
+
+const { isLocalBuildStale } = createRequire(import.meta.url)(
+  "./bundled-plugins.cjs",
+);
 
 const ID = /^[a-z0-9][a-z0-9-]*$/;
 const SOURCE_DIRS = new Set(["src", "locales", "migrations"]);
@@ -19,6 +24,27 @@ export function isPluginSourceChange(filename) {
   return SOURCE_DIRS.has(parts[0]);
 }
 
+/**
+ * Whether a watcher event in a plugin repo is an edit worth a rebuild.
+ *
+ * On Windows, fs.watch also reports a folder or file being read (its last
+ * access time changing, which NTFS writes lazily), so reading a repo looks
+ * like editing it. Folder events are ignored, and a file event only counts
+ * while its sources are newer than the last build. A path that no longer
+ * exists was deleted, which always counts.
+ */
+export function isPluginEdit(repo, filename, isStale = isLocalBuildStale) {
+  if (!isPluginSourceChange(filename)) return false;
+  let stat;
+  try {
+    stat = fs.statSync(path.join(repo, String(filename)));
+  } catch {
+    return true;
+  }
+  if (stat.isDirectory()) return false;
+  return isStale(repo);
+}
+
 /** Plugin repos under dir that can be built (manifest.json and node_modules). */
 export function findBuildablePlugins(dir) {
   const plugins = [];