From 3cc9aec988a47beda8eb9b93398f9ab7c5caabad Mon Sep 17 00:00:00 2001
From: Antoine du Hamel <duhamelantoine1995@gmail.com>
Date: Wed, 3 Feb 2021 18:55:15 +0100
Subject: [PATCH] module: runtime deprecate subpath folder mappings

PR-URL: https://github.com/nodejs/node/pull/37215
Reviewed-By: Guy Bedford <guybedford@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
---
 doc/api/deprecations.md                        | 16 +++++++---------
 doc/api/packages.md                            |  7 +++++--
 lib/internal/modules/esm/resolve.js            | 16 +---------------
 test/es-module/test-esm-local-deprecations.mjs |  3 ++-
 4 files changed, 15 insertions(+), 27 deletions(-)

diff --git a/doc/api/deprecations.md b/doc/api/deprecations.md
index bd92a3b32e17b6..18574f5e0a6227 100644
--- a/doc/api/deprecations.md
+++ b/doc/api/deprecations.md
@@ -2697,24 +2697,22 @@ Use `fs.rm(path, { recursive: true, force: true })`,
 ### DEP0148: Folder mappings in `"exports"` (trailing `"/"`)
 <!-- YAML
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/37215
+    description: Runtime deprecation.
   - version: v15.1.0
     pr-url: https://github.com/nodejs/node/pull/35747
-    description: Runtime deprecation.
+    description: Runtime deprecation for self-referencing imports.
   - version: v14.13.0
     pr-url: https://github.com/nodejs/node/pull/34718
     description: Documentation-only deprecation.
 -->
 
-Type: Runtime (supports [`--pending-deprecation`][])
+Type: Runtime
 
-Prior to [subpath patterns][] support, it was possible to define
+Using a trailing `"/"` to define
 [subpath folder mappings][] in the [subpath exports][] or
-[subpath imports][] fields using a trailing `"/"`.
-
-Without `--pending-deprecation`, runtime warnings occur only for exports
-resolutions not in `node_modules`. This means there will not be deprecation
-warnings for `"exports"` in dependencies. With `--pending-deprecation`, a
-runtime warning results no matter where the `"exports"` usage occurs.
+[subpath imports][] fields is deprecated. Use [subpath patterns][] instead.
 
 ### DEP0149: `http.IncomingMessage#connection`
 <!-- YAML
diff --git a/doc/api/packages.md b/doc/api/packages.md
index 66f1eec3480a20..f14770e34d90aa 100644
--- a/doc/api/packages.md
+++ b/doc/api/packages.md
@@ -386,9 +386,12 @@ targets, this expansion is dependent on only the files of the package itself.
 ### Subpath folder mappings
 <!-- YAML
 changes:
-  - version: v15.1.0
-    pr-url: https://github.com/nodejs/node/pull/35746
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/37215
     description: Runtime deprecation.
+  - version: v15.1.0
+    pr-url: https://github.com/nodejs/node/pull/35747
+    description: Runtime deprecation for self-referencing imports.
   - version:
     - v14.13.0
     - v12.20.0
diff --git a/lib/internal/modules/esm/resolve.js b/lib/internal/modules/esm/resolve.js
index d7e22368f90c8f..96d03a9c369e9d 100644
--- a/lib/internal/modules/esm/resolve.js
+++ b/lib/internal/modules/esm/resolve.js
@@ -16,7 +16,6 @@ const {
   String,
   StringPrototypeEndsWith,
   StringPrototypeIndexOf,
-  StringPrototypeLastIndexOf,
   StringPrototypeReplace,
   StringPrototypeSlice,
   StringPrototypeSplit,
@@ -60,23 +59,10 @@ const userConditions = getOptionValue('--conditions');
 const DEFAULT_CONDITIONS = ObjectFreeze(['node', 'import', ...userConditions]);
 const DEFAULT_CONDITIONS_SET = new SafeSet(DEFAULT_CONDITIONS);
 
-const pendingDeprecation = getOptionValue('--pending-deprecation');
 const emittedPackageWarnings = new SafeSet();
 function emitFolderMapDeprecation(match, pjsonUrl, isExports, base) {
   const pjsonPath = fileURLToPath(pjsonUrl);
-  if (!pendingDeprecation) {
-    const nodeModulesIndex =
-        StringPrototypeLastIndexOf(pjsonPath, sep + 'node_modules' + sep);
-    if (nodeModulesIndex !== -1) {
-      const afterNodeModulesPath =
-          StringPrototypeSlice(pjsonPath, nodeModulesIndex + 14, -13);
-      try {
-        const { packageSubpath } = parsePackageName(afterNodeModulesPath);
-        if (packageSubpath === '.')
-          return;
-      } catch {}
-    }
-  }
+
   if (emittedPackageWarnings.has(pjsonPath + '|' + match))
     return;
   emittedPackageWarnings.add(pjsonPath + '|' + match);
diff --git a/test/es-module/test-esm-local-deprecations.mjs b/test/es-module/test-esm-local-deprecations.mjs
index d9d86fefc06464..a1945f66f3422f 100644
--- a/test/es-module/test-esm-local-deprecations.mjs
+++ b/test/es-module/test-esm-local-deprecations.mjs
@@ -11,7 +11,8 @@ const deprecatedFoldersIgnore =
 
 const expectedWarnings = [
   '"./" in the "exports" field',
-  '"#self/" in the "imports" field'
+  '"#self/" in the "imports" field',
+  '"./folder/" in the "exports" field',
 ];
 
 process.addListener('warning', (warning) => {