From 5424b8a64d191599860b863b8b0cae253c1efc01 Mon Sep 17 00:00:00 2001
From: achingbrain <alex@achingbrain.net>
Date: Wed, 24 Mar 2021 07:54:42 +0000
Subject: [PATCH] fix: allow overriding entry point in browser field

Some modules are [published](https://unpkg.com/cborg@1.1.2/package.json) with no `main`
field in `package.json` and no `/index.js`, instead using `exports` to define the entry
point for the module.

They sometimes specify an entry point for the browser using a `"."` or `"./"` key in
the `browser` field, but currently these are broken with browserify as it tries to
resolve `/index.js` when no `main` field is present.

The change here is to allow define the entry point for the module using the `browser`
field:

```json
{
  "browser": {
    ".": "path/to/index.js"
  }
}
```
---
 index.js                                                  | 4 +++-
 .../entry-point-overridden-in-browser-field/foo/bar.js    | 0
 .../entry-point-overridden-in-browser-field/package.json  | 5 +++++
 test/modules-sync.js                                      | 5 +++++
 test/modules.js                                           | 8 ++++++++
 5 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 test/fixtures/node_modules/entry-point-overridden-in-browser-field/foo/bar.js
 create mode 100644 test/fixtures/node_modules/entry-point-overridden-in-browser-field/package.json

diff --git a/index.js b/index.js
index 8a1908a..b0de81f 100644
--- a/index.js
+++ b/index.js
@@ -169,7 +169,9 @@ function build_resolve_opts(opts, base) {
         }
 
         var replace_main = replacements[info.main || './index.js'] ||
-            replacements['./' + info.main || './index.js'];
+            replacements['./' + info.main || './index.js'] ||
+            replacements['.'] ||
+            replacements['./'];
 
         info.main = replace_main || info.main;
         return info;
diff --git a/test/fixtures/node_modules/entry-point-overridden-in-browser-field/foo/bar.js b/test/fixtures/node_modules/entry-point-overridden-in-browser-field/foo/bar.js
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/node_modules/entry-point-overridden-in-browser-field/package.json b/test/fixtures/node_modules/entry-point-overridden-in-browser-field/package.json
new file mode 100644
index 0000000..798dbaa
--- /dev/null
+++ b/test/fixtures/node_modules/entry-point-overridden-in-browser-field/package.json
@@ -0,0 +1,5 @@
+{
+  "browser": {
+      ".": "./foo/bar.js"
+  }
+}
diff --git a/test/modules-sync.js b/test/modules-sync.js
index 4ae3b64..a2aea1d 100644
--- a/test/modules-sync.js
+++ b/test/modules-sync.js
@@ -158,3 +158,8 @@ test('alt-browser field', function() {
     var path = resolve.sync('url', parent);
     assert.equal(path, require.resolve('./fixtures/node_modules/alt-browser-field/url-chromeapp'));
 });
+
+test('allow overriding entry point in browser field', function() {
+    var path = resolve.sync('entry-point-overridden-in-browser-field', { paths: [ fixtures_dir ], package: { main: 'fixtures' } });
+    assert.equal(path, require.resolve('./fixtures/node_modules/entry-point-overridden-in-browser-field/foo/bar.js'));
+});
diff --git a/test/modules.js b/test/modules.js
index ddf26d2..fc6687d 100644
--- a/test/modules.js
+++ b/test/modules.js
@@ -338,3 +338,11 @@ test('respect symlinks', function (done) {
         done();
     });
 });
+
+test('allow overriding entry point in browser field', function (done) {
+    resolve('entry-point-overridden-in-browser-field', { paths: [ fixtures_dir ] }, function(err, path, pkg) {
+        assert.ifError(err);
+        assert.equal(path, require.resolve('./fixtures/node_modules/entry-point-overridden-in-browser-field/foo/bar.js'));
+        done();
+    });
+});