Fix test case generation when no auxiliary support functions are required

Author: smowton

java/ql/src/utils/GenerateFlowTestCase.py

@@ -161,12 +161,17 @@ def getTuples(queryName, jsonResult, fname):
 
 scriptPath = os.path.dirname(sys.argv[0])
 
+def copyfile(fromName, toFileHandle):
+  with open(os.path.join(scriptPath, fromName), "r") as fromFileHandle:
+    shutil.copyfileobj(fromFileHandle, toFileHandle)
+
 with open(resultQl, "w") as f:
-  with open(os.path.join(scriptPath, "testHeader.qlfrag"), "r") as header:
-    shutil.copyfileobj(header, f)
-  f.write(", ".join('"%s"' % modelSpecRow[0].strip() for modelSpecRow in supportModelRows))
-  with open(os.path.join(scriptPath, "testFooter.qlfrag"), "r") as header:
-    shutil.copyfileobj(header, f)
+  copyfile("testHeader.qlfrag", f)
+  if len(supportModelRows) != 0:
+    copyfile("testModelsHeader.qlfrag", f)
+    f.write(", ".join('"%s"' % modelSpecRow[0].strip() for modelSpecRow in supportModelRows))
+    copyfile("testModelsFooter.qlfrag", f)
+  copyfile("testFooter.qlfrag", f)
 
 # Make an empty .expected file, since this is an inline-exectations test
 with open(os.path.join(sys.argv[3], "test.expected"), "w"):

java/ql/src/utils/testFooter.qlfrag

@@ -1,6 +1,3 @@
-      ]
-  }
-}
 
 class ValueFlowConf extends DataFlow::Configuration {
   ValueFlowConf() { this = "qltest:valueFlowConf" }

java/ql/src/utils/testHeader.qlfrag

@@ -3,9 +3,3 @@ import semmle.code.java.dataflow.DataFlow
 import semmle.code.java.dataflow.ExternalFlow
 import semmle.code.java.dataflow.TaintTracking
 import TestUtilities.InlineExpectationsTest
-
-class SummaryModelTest extends SummaryModelCsv {
-  override predicate row(string row) {
-    row =
-      [
-        //"package;type;overrides;name;signature;ext;inputspec;outputspec;kind",

java/ql/src/utils/testModelsFooter.qlfrag

@@ -0,0 +1,3 @@
+      ]
+  }
+}

java/ql/src/utils/testModelsHeader.qlfrag

@@ -0,0 +1,5 @@
+class SummaryModelTest extends SummaryModelCsv {
+  override predicate row(string row) {
+    row =
+      [
+        //"package;type;overrides;name;signature;ext;inputspec;outputspec;kind",