Java: Improve flow test case generator to emit a data extensions YAML file and qlpack file if needed.

java/ql/src/utils/flowtestcasegenerator/GenerateFlowTestCase.py

@@ -24,7 +24,9 @@ contain the needed classes.
 
 If --force is present, existing files may be overwritten.
 
-Requirements: `mvn` and `codeql` should both appear on your path.
+Requirements:
+ - `mvn` and `codeql` should both appear on your path.
+ - `--additional-packs /path/to/semmle-code/ql` should be added to your `.config/codeql/config` file.
 
 After test generation completes, any lines in specsToTest.csv that didn't produce tests are output.
 If this happens, check the spelling of class and method names, and the syntax of input and output specifications.
@@ -52,10 +54,12 @@ except Exception as e:
 
 resultJava = os.path.join(sys.argv[3], "Test.java")
 resultQl = os.path.join(sys.argv[3], "test.ql")
+resultYml = os.path.join(sys.argv[3], "test.model.yml")
+resultPack = os.path.join(sys.argv[3], "qlpack.yml")
 
-if not force and (os.path.exists(resultJava) or os.path.exists(resultQl)):
-    print("Won't overwrite existing files '%s' or '%s'" %
-          (resultJava, resultQl), file=sys.stderr)
+if not force and (os.path.exists(resultJava) or os.path.exists(resultQl) or os.path.exists(resultYml) or os.path.exists(resultPack)):
+    print("Won't overwrite existing files '%s', '%s', '%s' or '%s'." %
+          (resultJava, resultQl, resultYml, resultPack), file=sys.stderr)
     sys.exit(1)
 
 workDir = tempfile.mkdtemp()
@@ -127,7 +131,13 @@ queryDir = os.path.join(workDir, "query")
 os.makedirs(queryDir)
 qlFile = os.path.join(queryDir, "gen.ql")
 with open(os.path.join(queryDir, "qlpack.yml"), "w") as f:
-    f.write("name: test-generation-query\nversion: 0.0.0\nlibraryPathDependencies: codeql/java-queries")
+    f.write(f"""name: test-generation-query
+version: 0.0.0
+dependencies:
+  codeql/java-all: '*'
+  codeql/java-queries: '*'
+""")
+
 with open(qlFile, "w") as f:
     f.write(
         "import java\nimport utils.flowtestcasegenerator.GenerateFlowTestCase\n\nclass GenRow extends TargetSummaryModelCsv {\n\n\toverride predicate row(string r) {\n\t\tr = [\n")
@@ -207,11 +217,32 @@ def copyfile(fromName, toFileHandle):
 
 with open(resultQl, "w") as 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)
+
+if len(supportModelRows) != 0:
+    # Make a test extension file
+    with open(resultYml, "w") as f:
+        models = "\n".join('      - [%s]' %
+                          modelSpecRow[0].strip() for modelSpecRow in supportModelRows)
+        dataextensions = f"""extensions:
+  - addsTo:
+      pack: codeql/java-tests
+      extensible: extSummaryModel
+    data:
+{models}
+"""
+        f.write(dataextensions)
+    # Make a qlpack file such that the extension will be picked up
+    with open(resultPack, "w") as f:
+        f.write(f"""name: example-test-pack
+version: 0.0.0
+extractor: java
+dependencies:
+  codeql/java-all: '*'
+  codeql/java-queries: '*'
+  codeql/java-tests: '*'
+dataExtensions:
+  - test.model.yml
+""")
 
 # Make an empty .expected file, since this is an inline-exectations test
 with open(os.path.join(sys.argv[3], "test.expected"), "w"):