[experimental] Replace flaky test with deterministic test
Disables a non-deterministic test of the ResponseRandomizer
and replaces it with a deterministic test.
Bug: 43846
Change-Id: I772d0ebb7292d59cacce3adc632478595513b3de
diff --git a/src/algorithms/experimental/randomized_response_test.cc b/src/algorithms/experimental/randomized_response_test.cc
index 416d30f..0d01448 100644
--- a/src/algorithms/experimental/randomized_response_test.cc
+++ b/src/algorithms/experimental/randomized_response_test.cc
@@ -17,13 +17,32 @@
std::unique_ptr<RandomNumberGenerator> gen_;
};
+// Encode each index from 0 to 999 inclusive with a max index of 999, without randomizing. Each
+// index should be equal to its own encoding.
+TEST_F(ResponseRandomizerTest, Encode) {
+ uint32_t max_index = 999;
+ double p = 0.0;
+ auto randomizer = ResponseRandomizer(GetGenerator(), max_index, p);
+ std::vector<uint32_t> encoded_indices;
+ for (uint32_t i = 0; i <= max_index; i++) {
+ encoded_indices.push_back(randomizer.Encode(i));
+ }
+ int diff = 0;
+ for (uint32_t i = 0; i < max_index; i++) {
+ if (i != encoded_indices[i]) {
+ ++diff;
+ }
+ }
+ EXPECT_EQ(diff, 0);
+}
+
// Encode each index from 0 to 999 inclusive, giving a data-independent response with probability
// p = 0.25 and a max index of 999. The probability that an index is equal to its own encoding is:
// (1 - p) + p / (max_index + 1) = 0.7525.
//
// Count how many of the 1000 indices differ from their encoding. Fail if a Z-test at level 0.01
// rejects the hypothesis that Pr[i == randomizer.Encode(i)] is equal to 0.2475.
-TEST_F(ResponseRandomizerTest, Encode) {
+TEST_F(ResponseRandomizerTest, DISABLED_EncodeNonzeroP) {
uint32_t max_index = 999;
double p = 0.25;
auto randomizer = ResponseRandomizer(GetGenerator(), max_index, p);
