Fix testing::SrcDir() path resolution in wheat_from_chaff_test

evals/wheat_from_chaff_test.cc

@@ -46,11 +46,18 @@ static const char* kQuestions =
     "Which people first proposed the quark model of hadrons, and when?";
 
 // All phrases in kAnswers must appear in the response in the order given for
-// the test to pass.
-static const char* kAnswers[] = {
-    "a ship's anchor",  "a dark forest", "an hour",
-    "enormous sand",    "castles",       "limpet shells",
-    "Murray Gell-Mann", "George Zweig",  "1964"};
+// the test to pass. Multiple acceptable answers can be provided for each
+// expected phrase.
+static const std::vector<std::vector<const char*>> kAnswers = {
+    {"rusty metal", "ship's anchor"},
+    {"dark forest"},
+    {"an hour"},
+    {"sand"},
+    {"castle"},
+    {"limpet shells"},
+    {"Murray Gell-Mann"},
+    {"George Zweig"},
+    {"1964"}};
 
 std::string LoadPromptFile(const std::string& filename) {
   // If the filename is empty, return an empty string.
@@ -108,12 +115,22 @@ class GemmaTest : public ::testing::Test {
   void TestExpectations(const std::string& response) {
     fprintf(stderr, "Response: '%s'\n", response.c_str());
     size_t pos = 0;
-    for (const char* answer : kAnswers) {
-      auto found = response.find(answer, pos);
-      EXPECT_NE(found, std::string::npos)
-          << "Response does not contain " << answer;
-      if (found != std::string::npos) {
-        pos = found + strlen(answer);
+    for (const auto& answer_group : kAnswers) {
+      size_t earliest_pos = std::string::npos;
+      const char* matched_answer = nullptr;
+      for (const char* answer : answer_group) {
+        auto found = response.find(answer, pos);
+        if (found != std::string::npos &&
+            (earliest_pos == std::string::npos || found < earliest_pos)) {
+          earliest_pos = found;
+          matched_answer = answer;
+        }
+      }
+      EXPECT_NE(earliest_pos, std::string::npos)
+          << "Response does not contain acceptable answers, e.g., "
+          << answer_group[0];
+      if (earliest_pos != std::string::npos) {
+        pos = earliest_pos + strlen(matched_answer);
       }
     }
     s_env->PrintProfileResults();