fix(pnp): report missing files in watch mode

.yarn/versions/371a1b00.yml

@@ -0,0 +1,27 @@
+releases:
+  "@yarnpkg/cli": patch
+  "@yarnpkg/plugin-pnp": patch
+  "@yarnpkg/pnp": patch
+
+declined:
+  - "@yarnpkg/plugin-compat"
+  - "@yarnpkg/plugin-constraints"
+  - "@yarnpkg/plugin-dlx"
+  - "@yarnpkg/plugin-essentials"
+  - "@yarnpkg/plugin-init"
+  - "@yarnpkg/plugin-interactive-tools"
+  - "@yarnpkg/plugin-nm"
+  - "@yarnpkg/plugin-npm-cli"
+  - "@yarnpkg/plugin-pack"
+  - "@yarnpkg/plugin-patch"
+  - "@yarnpkg/plugin-pnpm"
+  - "@yarnpkg/plugin-stage"
+  - "@yarnpkg/plugin-typescript"
+  - "@yarnpkg/plugin-version"
+  - "@yarnpkg/plugin-workspace-tools"
+  - "@yarnpkg/builder"
+  - "@yarnpkg/core"
+  - "@yarnpkg/doctor"
+  - "@yarnpkg/nm"
+  - "@yarnpkg/pnpify"
+  - "@yarnpkg/sdks"

CHANGELOG.md

@@ -80,6 +80,7 @@ The following changes only affect people writing Yarn plugins:
 
 - Updates the PnP compatibility layer for TypeScript v4.9.4.
 - The patched filesystem now supports `FileHandle.readLines`.
+- PnP now reports missing files when in watch mode.
 
 ## 3.3.0
 

packages/yarnpkg-pnp/sources/esm-loader/hooks/load.ts

@@ -1,9 +1,9 @@
-import {VirtualFS, npath}                      from '@yarnpkg/fslib';
-import fs                                      from 'fs';
-import {fileURLToPath, pathToFileURL}          from 'url';
+import {VirtualFS, npath}                                                      from '@yarnpkg/fslib';
+import fs                                                                      from 'fs';
+import {fileURLToPath, pathToFileURL}                                          from 'url';
 
-import {HAS_JSON_IMPORT_ASSERTION_REQUIREMENT} from '../loaderFlags';
-import * as loaderUtils                        from '../loaderUtils';
+import {HAS_JSON_IMPORT_ASSERTION_REQUIREMENT, WATCH_MODE_MESSAGE_USES_ARRAYS} from '../loaderFlags';
+import * as loaderUtils                                                        from '../loaderUtils';
 
 // The default `load` doesn't support reading from zip files
 export async function load(
@@ -37,12 +37,13 @@ export async function load(
     // At the time of writing Node.js reports all loaded URLs itself so
     // we technically only need to do this for virtual files but in the
     // event that ever changes we report everything.
+    const pathToSend = pathToFileURL(
+      npath.fromPortablePath(
+        VirtualFS.resolveVirtual(npath.toPortablePath(filePath)),
+      ),
+    ).href;
     process.send({
-      'watch:import': pathToFileURL(
-        npath.fromPortablePath(
-          VirtualFS.resolveVirtual(npath.toPortablePath(filePath)),
-        ),
-      ).href,
+      'watch:import': WATCH_MODE_MESSAGE_USES_ARRAYS ? [pathToSend] : pathToSend,
     });
   }
 

packages/yarnpkg-pnp/sources/esm-loader/loaderFlags.ts

@@ -8,3 +8,6 @@ export const HAS_UNFLAGGED_JSON_MODULES = major > 17 || (major === 17 && minor >
 
 // JSON modules requires import assertions after https://github.com/nodejs/node/pull/40250
 export const HAS_JSON_IMPORT_ASSERTION_REQUIREMENT = major > 17 || (major === 17 && minor >= 1) || (major === 16 && minor > 14);
+
+// The message switched to using an array in https://github.com/nodejs/node/pull/45348
+export const WATCH_MODE_MESSAGE_USES_ARRAYS = major > 19 || (major === 19 && minor >= 2);

packages/yarnpkg-pnp/sources/loader/applyPatch.ts

@@ -27,14 +27,6 @@ declare global {
   }
 }
 
-// https://github.com/nodejs/node/pull/44366
-const shouldReportRequiredModules = process.env.WATCH_REPORT_DEPENDENCIES;
-function reportModuleToWatchMode(filename: NativePath) {
-  if (shouldReportRequiredModules && process.send) {
-    process.send({'watch:require': npath.fromPortablePath(VirtualFS.resolveVirtual(npath.toPortablePath(filename)))});
-  }
-}
-
 export function applyPatch(pnpapi: PnpApi, opts: ApplyPatchOptions) {
   /**
    * The cache that will be used for all accesses occurring outside of a PnP context.
@@ -175,7 +167,7 @@ export function applyPatch(pnpapi: PnpApi, opts: ApplyPatchOptions) {
     const module = new Module(modulePath, parent ?? undefined) as PatchedModule;
     module.pnpApiPath = moduleApiPath;
 
-    reportModuleToWatchMode(modulePath);
+    nodeUtils.reportRequiredFilesToWatchMode([modulePath]);
 
     entry.cache[modulePath] = module;
 

packages/yarnpkg-pnp/sources/loader/makeApi.ts

@@ -830,6 +830,8 @@ export function makeApi(runtimeState: RuntimeState, opts: MakeApiOptions): PnpAp
     if (qualifiedPath) {
       return ppath.normalize(qualifiedPath);
     } else {
+      nodeUtils.reportRequiredFilesToWatchMode(candidates.map(candidate => npath.fromPortablePath(candidate)));
+
       const unqualifiedPathForDisplay = getPathForDisplay(unqualifiedPath);
 
       const containingPackage = findPackageLocator(unqualifiedPath);

packages/yarnpkg-pnp/sources/loader/nodeUtils.ts

@@ -1,7 +1,9 @@
-import {NativePath, npath} from '@yarnpkg/fslib';
-import fs                  from 'fs';
-import {Module}            from 'module';
-import path                from 'path';
+import {NativePath, npath, VirtualFS}   from '@yarnpkg/fslib';
+import fs                               from 'fs';
+import {Module}                         from 'module';
+import path                             from 'path';
+
+import {WATCH_MODE_MESSAGE_USES_ARRAYS} from '../esm-loader/loaderFlags';
 
 // @ts-expect-error
 const builtinModules = new Set(Module.builtinModules || Object.keys(process.binding(`natives`)));
@@ -55,3 +57,18 @@ Instead change the require of ${basename} in ${parentPath} to a dynamic import()
   err.code = `ERR_REQUIRE_ESM`;
   return err;
 }
+
+// https://github.com/nodejs/node/pull/44366
+// https://github.com/nodejs/node/pull/45348
+export function reportRequiredFilesToWatchMode(files: Array<NativePath>) {
+  if (process.env.WATCH_REPORT_DEPENDENCIES && process.send) {
+    files = files.map(filename => npath.fromPortablePath(VirtualFS.resolveVirtual(npath.toPortablePath(filename))));
+    if (WATCH_MODE_MESSAGE_USES_ARRAYS) {
+      process.send({'watch:require': files});
+    } else {
+      for (const filename of files) {
+        process.send({'watch:require': filename});
+      }
+    }
+  }
+}