[TEST] Fix sync problems in OTLP File exporter tests. (#3031)

Author: owent

exporters/otlp/test/otlp_file_exporter_test.cc

@@ -25,6 +25,7 @@
 #include "nlohmann/json.hpp"
 
 #include <chrono>
+#include <iostream>
 #include <sstream>
 
 using namespace testing;
@@ -112,13 +113,24 @@ class OtlpFileExporterTestPeer : public ::testing::Test
 
     provider->ForceFlush();
 
+    output.flush();
+    output.sync();
+    auto check_json_text = output.str();
+    if (!check_json_text.empty())
     {
-      auto check_json        = nlohmann::json::parse(output.str(), nullptr, false);
-      auto resource_span     = *check_json["resourceSpans"].begin();
-      auto scope_span        = *resource_span["scopeSpans"].begin();
-      auto span              = *scope_span["spans"].begin();
-      auto received_trace_id = span["traceId"].get<std::string>();
-      EXPECT_EQ(received_trace_id, report_trace_id);
+      auto check_json = nlohmann::json::parse(check_json_text, nullptr, false);
+      if (!check_json.is_discarded())
+      {
+        auto resource_span     = *check_json["resourceSpans"].begin();
+        auto scope_span        = *resource_span["scopeSpans"].begin();
+        auto span              = *scope_span["spans"].begin();
+        auto received_trace_id = span["traceId"].get<std::string>();
+        EXPECT_EQ(received_trace_id, report_trace_id);
+      }
+      else
+      {
+        FAIL() << "Failed to parse json:" << check_json_text;
+      }
     }
   }
 };

exporters/otlp/test/otlp_file_log_record_exporter_test.cc

@@ -122,8 +122,12 @@ class OtlpFileLogRecordExporterTestPeer : public ::testing::Test
 
     provider->ForceFlush();
 
+    output.flush();
+    output.sync();
+    auto check_json_text = output.str();
+    if (!check_json_text.empty())
     {
-      auto check_json        = nlohmann::json::parse(output.str(), nullptr, false);
+      auto check_json        = nlohmann::json::parse(check_json_text, nullptr, false);
       auto resource_logs     = *check_json["resourceLogs"].begin();
       auto scope_logs        = *resource_logs["scopeLogs"].begin();
       auto scope             = scope_logs["scope"];

exporters/otlp/test/otlp_file_metric_exporter_test.cc

@@ -106,8 +106,12 @@ class OtlpFileMetricExporterTestPeer : public ::testing::Test
 
     exporter->ForceFlush();
 
+    output.flush();
+    output.sync();
+    auto check_json_text = output.str();
+    if (!check_json_text.empty())
     {
-      auto check_json = nlohmann::json::parse(output.str(), nullptr, false);
+      auto check_json = nlohmann::json::parse(check_json_text, nullptr, false);
 
       auto resource_metrics = *check_json["resourceMetrics"].begin();
       auto scope_metrics    = *resource_metrics["scopeMetrics"].begin();
@@ -167,8 +171,12 @@ class OtlpFileMetricExporterTestPeer : public ::testing::Test
 
     exporter->ForceFlush();
 
+    output.flush();
+    output.sync();
+    auto check_json_text = output.str();
+    if (!check_json_text.empty())
     {
-      auto check_json = nlohmann::json::parse(output.str(), nullptr, false);
+      auto check_json = nlohmann::json::parse(check_json_text, nullptr, false);
 
       auto resource_metrics = *check_json["resourceMetrics"].begin();
       auto scope_metrics    = *resource_metrics["scopeMetrics"].begin();
@@ -233,8 +241,12 @@ class OtlpFileMetricExporterTestPeer : public ::testing::Test
 
     exporter->ForceFlush();
 
+    output.flush();
+    output.sync();
+    auto check_json_text = output.str();
+    if (!check_json_text.empty())
     {
-      auto check_json = nlohmann::json::parse(output.str(), nullptr, false);
+      auto check_json = nlohmann::json::parse(check_json_text, nullptr, false);
 
       auto resource_metrics = *check_json["resourceMetrics"].begin();
       auto scope_metrics    = *resource_metrics["scopeMetrics"].begin();