From e2220c4f1260fddae49b70b2ef477b7b1a261373 Mon Sep 17 00:00:00 2001
From: Bert <bert.hertogen@live.be>
Date: Wed, 22 Aug 2018 14:12:21 +0200
Subject: [PATCH] fix(schema): allow the `output` filename to be a `{Function}`
 (#1409)

---
 lib/optionsSchema.json  |  3 +++
 test/Validation.test.js | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/lib/optionsSchema.json b/lib/optionsSchema.json
index cde973e162..8ee6f0798e 100644
--- a/lib/optionsSchema.json
+++ b/lib/optionsSchema.json
@@ -36,6 +36,9 @@
         },
         {
           "type": "string"
+        },
+        {
+          "instanceof": "Function"
         }
       ]
     },
diff --git a/test/Validation.test.js b/test/Validation.test.js
index 86e7278f5e..943d2bc981 100644
--- a/test/Validation.test.js
+++ b/test/Validation.test.js
@@ -70,6 +70,18 @@ describe('Validation', () => {
     });
   });
 
+  describe('filename', () => {
+    it('should allow filename to be a function', () => {
+      try {
+        // eslint-disable-next-line no-new
+        new Server(compiler, { filename: () => {} });
+      } catch (e) {
+        if (!(e instanceof OptionsValidationError)) { throw e; }
+        throw new Error("Validation failed and it shouldn't");
+      }
+    });
+  });
+
   describe('checkHost', () => {
     it('should always allow any host if options.disableHostCheck is set', () => {
       const options = {