Index: cfe/trunk/lib/Format/FormatToken.h
===================================================================
--- cfe/trunk/lib/Format/FormatToken.h
+++ cfe/trunk/lib/Format/FormatToken.h
@@ -680,6 +680,7 @@
     kw_function = &IdentTable.get("function");
     kw_get = &IdentTable.get("get");
     kw_import = &IdentTable.get("import");
+    kw_infer = &IdentTable.get("infer");
     kw_is = &IdentTable.get("is");
     kw_let = &IdentTable.get("let");
     kw_module = &IdentTable.get("module");
@@ -751,6 +752,7 @@
   IdentifierInfo *kw_function;
   IdentifierInfo *kw_get;
   IdentifierInfo *kw_import;
+  IdentifierInfo *kw_infer;
   IdentifierInfo *kw_is;
   IdentifierInfo *kw_let;
   IdentifierInfo *kw_module;
Index: cfe/trunk/lib/Format/TokenAnnotator.cpp
===================================================================
--- cfe/trunk/lib/Format/TokenAnnotator.cpp
+++ cfe/trunk/lib/Format/TokenAnnotator.cpp
@@ -3088,6 +3088,12 @@
       return Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None;
     if (Right.is(Keywords.kw_as))
       return false; // must not break before as in 'x as type' casts
+    if (Right.isOneOf(Keywords.kw_extends, Keywords.kw_infer)) {
+      // extends and infer can appear as keywords in conditional types:
+      //   https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-8.html#conditional-types
+      // do not break before them, as the expressions are subject to ASI.
+      return false;
+    }
     if (Left.is(Keywords.kw_as))
       return true;
     if (Left.is(TT_JsNonNullAssertion))
Index: cfe/trunk/unittests/Format/FormatTestJS.cpp
===================================================================
--- cfe/trunk/unittests/Format/FormatTestJS.cpp
+++ cfe/trunk/unittests/Format/FormatTestJS.cpp
@@ -2308,5 +2308,14 @@
   verifyFormat("callFoo(/*spaceAfterParameterNamingComment=*/ 1);");
 }
 
+TEST_F(FormatTestJS, ConditionalTypes) {
+  // Formatting below is not necessarily intentional, this just ensures that
+  // clang-format does not break the code.
+  verifyFormat( // wrap
+      "type UnionToIntersection<U> =\n"
+      "    (U extends any ? (k: U) => void :\n"
+      "                     never) extends((k: infer I) => void) ? I : never;");
+}
+
 } // end namespace tooling
 } // end namespace clang