Added new unit test for register.cc (#1712)

* new unit test for register.cc

Signed-off-by: Deeksha Goplani <deeksha.goplani@amd.com>

* Add new register API tests

* Fix debug message ordering issue

---------

Signed-off-by: Deeksha Goplani <deeksha.goplani@amd.com>
Co-authored-by: Atul Kulkarni <atul.kulkarni@amd.com>

test/common/ProcessIsolatedTestRunner.cpp

@@ -402,6 +402,9 @@ bool ProcessIsolatedTestRunner::executeAllTests(const ExecutionOptions& options)
             continue;
         }
 
+        // Flush all output before fork to prevent child from inheriting unflushed buffers
+        fflush(NULL);
+
         pid_t pid = fork();
 
         if(pid == 0)
@@ -435,6 +438,10 @@ bool ProcessIsolatedTestRunner::executeAllTests(const ExecutionOptions& options)
             {
                 INFO("Running isolated test '%s' (PID: %d)\n", testConfig.name.c_str(), pid);
             }
+            // Flush parent's output before reading from child pipes to ensure proper ordering
+            fflush(stdout);
+            fflush(stderr);
+
             int            status;
             CapturedOutput output = captureProcessOutput(stdout_fd, stderr_fd, pid, &status);
 
@@ -442,6 +449,9 @@ bool ProcessIsolatedTestRunner::executeAllTests(const ExecutionOptions& options)
             auto duration
                 = std::chrono::duration_cast<std::chrono::milliseconds>(endTime - startTime);
 
+            // Display captured output BEFORE status messages for proper sequencing
+            displayCapturedOutput(output, testConfig.name);
+
             TestResult testResult;
             testResult.testName  = testConfig.name;
             testResult.processId = pid;
@@ -530,8 +540,6 @@ bool ProcessIsolatedTestRunner::executeAllTests(const ExecutionOptions& options)
                 testResult.errorMessage = "Failed to wait for process";
             }
 
-            displayCapturedOutput(output, testConfig.name);
-
             recordTestResult(testResult);
 
             // Stop on first failure if requested