fix(gapic-common): Hardened deadline determination against Time.now hacking

Author: dazuma

gapic-common/lib/gapic/grpc/service_stub/rpc_call.rb

@@ -145,13 +145,21 @@ def calculate_deadline options
         return if options.timeout.nil?
         return if options.timeout.negative?
 
-        Time.now + options.timeout
+        current_time + options.timeout
       end
 
       def check_retry? deadline
         return true if deadline.nil?
 
-        deadline > Time.now
+        deadline > current_time
+      end
+
+      def current_time
+        # An alternative way of saying Time.now without actually calling
+        # Time.now. This allows clients that replace Time.now (e.g. via the
+        # timecop gem) to do so without interfering with the deadline.
+        nanos = Process.clock_gettime Process::CLOCK_REALTIME, :nanosecond
+        Time.at(nanos / 1_000_000_000, nanos % 1_000_000_000, :nanosecond)
       end
     end
   end

gapic-common/lib/gapic/headers.rb

@@ -38,7 +38,6 @@ module Headers
     def self.x_goog_api_client ruby_version: nil, lib_name: nil, lib_version: nil, gax_version: nil,
                                gapic_version: nil, grpc_version: nil, rest_version: nil, protobuf_version: nil,
                                transports_version_send: [:grpc]
-
       ruby_version ||= ::RUBY_VERSION
       gax_version  ||= ::Gapic::Common::VERSION
       grpc_version ||= ::GRPC::VERSION if defined? ::GRPC::VERSION

gapic-common/test/gapic/grpc/rpc_call/retry/raise_test.rb

@@ -74,9 +74,9 @@ def test_times_out
 
     rpc_call = Gapic::ServiceStub::RpcCall.new api_meth_stub
 
-    time_now = Time.now
-    time_proc = lambda do
-      time_now += 60
+    nanos = Process.clock_gettime Process::CLOCK_REALTIME, :nanosecond
+    time_proc = lambda do |*|
+      nanos += 60_000_000_000
     end
 
     sleep_mock = Minitest::Mock.new
@@ -92,12 +92,13 @@ def test_times_out
     )
 
     Kernel.stub :sleep, sleep_proc do
-      Time.stub :now, time_proc do
+      Process.stub :clock_gettime, time_proc do
         assert_raises GRPC::BadStatus do
           rpc_call.call Object.new, options: options
         end
 
-        assert_equal time_now, deadline_arg
+        expected_time = Time.at(nanos / 1_000_000_000, nanos % 1_000_000_000, :nanosecond)
+        assert_equal expected_time, deadline_arg
         assert_equal to_attempt, call_count
       end
     end

gapic-common/test/gapic/grpc/rpc_call/retry/retry_test.rb

@@ -58,12 +58,13 @@ def test_retries_with_exponential_backoff
     end
     sleep_proc = ->(count) { sleep_mock.sleep count }
 
-    time_now = Time.now
-    Time.stub :now, time_now do
+    nanos = Process.clock_gettime Process::CLOCK_REALTIME, :nanosecond
+    expected_time = Time.at(nanos / 1_000_000_000, nanos % 1_000_000_000, :nanosecond)
+    Process.stub :clock_gettime, nanos do
       Kernel.stub :sleep, sleep_proc do
         assert_equal 1729, rpc_call.call(Object.new, options: options)
         assert_equal 5, inner_attempts
-        assert_equal time_now + 300, deadline_arg
+        assert_equal(expected_time + 300, deadline_arg)
       end
     end