fix $ref fragment preserve

ref-resolver.js

@@ -100,7 +100,7 @@ function jsonSchemaResolver (options) {
     debug('Processed root schema')
 
     debug('Generating %d refs', allRefs.length)
-    allRefs.forEach(({ baseUri, ref, json }) => {
+    allRefs.forEach(({ baseUri, ref, refUri, json }) => {
       debug('Evaluating $ref %s', ref)
       if (ref[0] === '#') { return }
 
@@ -110,7 +110,7 @@ function jsonSchemaResolver (options) {
         return
       }
       evaluatedJson[kConsumed] = true
-      json.$ref = `#/definitions/${evaluatedJson[kRefToDef]}`
+      json.$ref = `#/definitions/${evaluatedJson[kRefToDef]}${refUri.fragment || ''}`
     })
 
     if (externalSchemas) {
@@ -166,6 +166,7 @@ function jsonSchemaResolver (options) {
     const ref = URI.serialize(refUri)
     allRefs.push({
       baseUri: URI.serialize(baseUri),
+      refUri,
       ref,
       json
     })

test/ref-fragment.test.js

@@ -0,0 +1,53 @@
+'use strict'
+
+const { test } = require('tap')
+
+const RefResolver = require('../ref-resolver')
+
+// eslint-disable-next-line
+const save = (out) => require('fs').writeFileSync(`./out-${Date.now()}.json`, JSON.stringify(out, null, 2))
+
+test('Preserve $ref fragment', t => {
+  t.plan(1)
+  const opts = {
+    externalSchemas: [
+      {
+        $id: 'example',
+        type: 'object',
+        properties: {
+          hello: { type: 'string' }
+        }
+      }
+    ]
+  }
+  const resolver = RefResolver()
+
+  const out = resolver.resolve({
+    $id: 'my-schema',
+    type: 'object',
+    properties: {
+      world: { $ref: 'example#/properties/hello' }
+    }
+  }, opts)
+
+  t.deepEqual(out, {
+    $id: 'my-schema',
+    type: 'object',
+    properties: {
+      world: {
+        $ref: '#/definitions/def-0/properties/hello'
+      }
+    },
+    definitions: {
+      'def-0': {
+        $id: 'example',
+        type: 'object',
+        properties: {
+          hello: {
+            type: 'string'
+          }
+        }
+      }
+    }
+  }, 'the $ref fragment has been preserved')
+})