diff --git a/test/helpers.tcl b/test/helpers.tcl
new file mode 100644
index 00000000..46eb84c9
--- /dev/null
+++ b/test/helpers.tcl
@@ -0,0 +1,41 @@
+# Helper functions common to multiple regressions.
+
+set test_dir [file dirname [file normalize [info script]]]
+set result_dir [file join $test_dir "results"]
+
+# puts [exec cat $file] without forking.
+proc report_file { file } {
+  set stream [open $file r]
+  if { [file extension $file] == ".gz" } {
+    zlib push gunzip $stream
+  }
+  gets $stream line
+  while { ![eof $stream] } {
+    puts $line
+    gets $stream line
+  }
+  close $stream
+}
+
+proc report_file_filter { file filter } {
+  set stream [open $file r]
+  gets $stream line
+  while { ![eof $stream] } {
+    set index [string first $filter $line]
+    if { $index != -1 } {
+      set line [string replace $line $index [expr $index + [string length $filter] - 1]]
+    }
+    puts $line
+    gets $stream line
+  }
+  close $stream
+}
+
+proc make_result_file { filename } {
+  variable result_dir
+  return [file join $result_dir $filename]
+}
+
+proc sort_objects { objects } {
+  return [sta::sort_by_full_name $objects]
+}