chore: resolves locally referenced package exports

index.js

@@ -226,11 +226,40 @@ function Hook (modules, options, onrequire) {
 
       let matchFound = false
       if (hasWhitelist) {
-        if (!id.startsWith('.') && modules.includes(id)) {
+        if (id.startsWith('.') === true && modules.includes(id) === false) {
+          // Try to resolve a package export relative to the base package.
+          // If found, and the package export is in the allow list, return
+          // success. Basically, we take a required module like
+          // `../dist/foo/bar.cjs` and narrow it down to what is likely present
+          // in the package exports.
+          let doWork = true
+          const parts = id.split('/')
+          const fileName = parts[parts.length - 1]
+          parts[parts.length - 1] = path.basename(fileName, path.extname(fileName))
+          do {
+            try {
+              parts.shift()
+              if (parts.length === 0) {
+                // We couldn't find anything, so let the rest of the algorithm
+                // play out.
+                doWork = false
+                continue
+              }
+
+              const exportName = moduleName + '/' + parts.join('/')
+              require.resolve(exportName)
+              moduleName = exportName
+              if (modules.includes(exportName) === true) {
+                matchFound = true
+              }
+              doWork = false
+            } catch {}
+          } while (doWork === true)
+        } else if (!id.startsWith('.') && modules.includes(id)) {
           // Not starting with '.' means `id` is identifying a module path,
           // as opposed to a local file path. (Note: I'm not sure about
           // absolute paths, but those are handled above.)
-          // If this `id` is in `modules`, then this could be a match to an
+          // If this `id` is in `modules`, then this could be a match to a
           // package "exports" entry point that wouldn't otherwise match below.
           moduleName = id
           matchFound = true

package.json

@@ -14,6 +14,7 @@
     "@babel/preset-env": "^7.9.5",
     "@babel/preset-typescript": "^7.9.0",
     "@babel/register": "^7.9.0",
+    "@langchain/core": "^0.1.57",
     "ipp-printer": "^1.0.0",
     "patterns": "^1.0.3",
     "roundround": "^0.2.0",

test/mapped-exports.js

@@ -6,6 +6,7 @@ const { Hook } = require('../')
 
 // Mapped export tests require Node.js >=12.17.0 for "exports" support in package.json.
 const nodeSupportsExports = semver.lt(process.version, '12.17.0')
+const node18AndAbove = semver.gte(process.version, '18.0.0')
 
 test('handles mapped exports: mapped-exports/foo', { skip: nodeSupportsExports }, function (t) {
   t.plan(2)
@@ -42,3 +43,31 @@ test('handles mapped exports: mapped-exports/bar', { skip: nodeSupportsExports }
 
   hook.unhook()
 })
+
+test(
+  'handles mapped exports: picks up allow listed resolved module',
+  { skip: nodeSupportsExports || node18AndAbove === false },
+  function (t) {
+    t.plan(3)
+
+    let hookHit = false
+    const hook = new Hook(['@langchain/core/callbacks/manager'], function (exports, name) {
+      t.equal(name, '@langchain/core/callbacks/manager', 'hook name matches')
+      hookHit = true
+      return exports
+    })
+
+    const { Tool } = require('@langchain/core/tools')
+    const MyTool = class MyTool extends Tool {
+      _call () {
+        t.pass('tool was executed successfully')
+      }
+    }
+
+    const tool = new MyTool()
+    tool.call('foo', [() => {}])
+    t.equal(hookHit, true, 'hook was hit successfully')
+
+    hook.unhook()
+  }
+)