Index: lib/Format/ContinuationIndenter.cpp
===================================================================
--- lib/Format/ContinuationIndenter.cpp
+++ lib/Format/ContinuationIndenter.cpp
@@ -701,8 +701,18 @@
     State.Stack.back().BreakBeforeParameter = false;
 
   if (!DryRun) {
+    unsigned MaxEmptyLinesToKeep = Style.MaxEmptyLinesToKeep + 1;
+    if (Style.Language == FormatStyle::LK_JavaScript &&
+        Current.is(tok::r_brace) && Current.MatchingParen &&
+        Current.MatchingParen->Previous &&
+        Current.MatchingParen->Previous->is(TT_JsFatArrow)) {
+      // JavaScript arrow functions are experssions, thus their r_brace is not
+      // on its own line, and thus not covered by UnwrappedLineFormatter's logic
+      // about removing empty lines on closing blocks. Special case it here.
+      MaxEmptyLinesToKeep = 0;
+    }
     unsigned Newlines = std::max(
-        1u, std::min(Current.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1));
+        1u, std::min(Current.NewlinesBefore, MaxEmptyLinesToKeep));
     bool ContinuePPDirective =
         State.Line->InPPDirective && State.Line->Type != LT_ImportStatement;
     Whitespaces.replaceWhitespace(Current, Newlines, State.Column, State.Column,
Index: unittests/Format/FormatTestJS.cpp
===================================================================
--- unittests/Format/FormatTestJS.cpp
+++ unittests/Format/FormatTestJS.cpp
@@ -1606,6 +1606,16 @@
       Style);
 }
 
+TEST_F(FormatTestJS, RemoveEmptyLinesTrailingArrowFunctions) {
+  verifyFormat("x = () => {\n"
+               "  foo();\n"
+               "};\n",
+               "x = () => {\n"
+               "  foo();\n"
+               "\n"
+               "};\n");
+}
+
 TEST_F(FormatTestJS, Modules) {
   verifyFormat("import SomeThing from 'some/module.js';");
   verifyFormat("import {X, Y} from 'some/module.js';");