When we add a new binding test, say bindings/scripts/test/TestSupplemental.idl, run-bindings-tests just shows diff error because reference files (i.e. {V8,JS,...}TestSupplemental.h and {V8,JS,...}TestSupplemental.cpp) do not yet exist: FAIL: (V8) V8TestSupplemental.h diff: WebCore/bindings/scripts/test/V8/V8TestSupplemental.h: No such file or directory FAIL: (V8) V8TestSupplemental.cpp diff: WebCore/bindings/scripts/test/V8/V8TestSupplemental.cpp: No such file or directory That way there is no way to check the result of the newly added binding test, unless we run run-bindings-tests with --reset-results and in fact update the reference files. However, --reset-results updates other reference files that we do not yet want to update in order to check diff. This is not user-friendly. Instead, we should treat a non-existent reference file as an empty file and show the result of the newly added binding test, like this: FAIL: (V8) V8TestSupplemental.h --- WebCore/bindings/scripts/test/V8/V8TestSupplemental.h 1970-01-01 09:00:00.000000000 +0900 +++ /tmp/tmpmX2i2F/V8TestSupplemental.h 2011-11-28 11:08:34.150707677 +0900 @@ -0,0 +1,84 @@ +/* + This file is part of the WebKit open source project. + This file has been generated by generate-bindings.pl. DO NOT MODIFY! + (omitted) FAIL: (V8) V8TestSupplemental.cpp --- WebCore/bindings/scripts/test/V8/V8TestSupplemental.cpp 1970-01-01 09:00:00.000000000 +0900 +++ /tmp/tmpmX2i2F/V8TestSupplemental.cpp 2011-11-28 11:08:34.150707677 +0900 @@ -0,0 +1,159 @@ +/* + This file is part of the WebKit open source project. + This file has been generated by generate-bindings.pl. DO NOT MODIFY! (omitted)