fix: sub-path module resolve wrong with pkg browser field

[ycjcl868]

Close #2002

[evanw]

I just tried this out. Your PR does fix that issue. However, it breaks some test cases on https://github.com/evanw/package-json-browser-tests that were previously working, so we'll need to find a different fix that keeps everything working:

entry.js:
  require('foo')
package.json:
  { "browser": { "./foo": "./file" } }
file.js:
  input.works = true

entry.js:
  require('pkg')
node_modules/pkg/index.js:
  require('foo/bar')
node_modules/pkg/package.json:
  { "browser": { "./foo/bar": "./file" } }
node_modules/pkg/file.js:
  input.works = true

entry.js:
  require('pkg')
package.json:
  { "browser": { "pkg2": "pkg3" } }
node_modules/pkg/index.js:
  require('pkg2')
node_modules/pkg/package.json:
  { "browser": { "./pkg2": "./file" } }
node_modules/pkg/file.js:
  input.works = true

The https://github.com/evanw/package-json-browser-tests repo is where I'm have a collection of cross-tool tests for this feature. I'll add your tests from this PR to that repo too.

[ycjcl868]

I just tried this out. Your PR does fix that issue. However, it breaks some test cases on https://github.com/evanw/package-json-browser-tests that were previously working, so we'll need to find a different fix that keeps everything working:

entry.js:
  require('foo')
package.json:
  { "browser": { "./foo": "./file" } }
file.js:
  input.works = true

entry.js:
  require('pkg')
node_modules/pkg/index.js:
  require('foo/bar')
node_modules/pkg/package.json:
  { "browser": { "./foo/bar": "./file" } }
node_modules/pkg/file.js:
  input.works = true

entry.js:
  require('pkg')
package.json:
  { "browser": { "pkg2": "pkg3" } }
node_modules/pkg/index.js:
  require('pkg2')
node_modules/pkg/package.json:
  { "browser": { "./pkg2": "./file" } }
node_modules/pkg/file.js:
  input.works = true

The https://github.com/evanw/package-json-browser-tests repo is where I'm have a collection of cross-tool tests for this feature. I'll add your tests from this PR to that repo too.

Thanks!