Add merge script for transpile-tests results

This adds a simple script to merge data from multiple sharded calls
to transpile_tests.py. We keep the merge script side-by-side with
the main script to ease changing details in the data later, e.g.
adding additional keys.

This also drops two redundant entries from the current format.

Bug: 442444727
Change-Id: I774c078455028a01eb97276b90120a0f03c14f7a
Reviewed-on: https://chrome-internal-review.googlesource.com/c/v8/fuzzilli/+/8832116
Reviewed-by: Matthias Liedtke <mliedtke@google.com>
Commit-Queue: Michael Achenbach <machenbach@google.com>

Author: mi-ac

Tools/transpile_tests/merge_json_results.py

@@ -0,0 +1,65 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Script to merge multiple output json files from transpile_tests.py into one.
+"""
+
+import argparse
+import json
+import sys
+
+
+def merge_test_results(inputs):
+  num_tests = 0
+  failures = []
+  for result in inputs:
+    num_tests += result["num_tests"]
+    failures += result["failures"]
+
+  return {
+    'num_tests': num_tests,
+    'failures': failures,
+  }
+
+
+def parse_args(args):
+  parser = argparse.ArgumentParser()
+  parser.add_argument(
+    '--json-input', action='append', required=True,
+    help='Path to a json results file from transpile_tests.py.')
+  parser.add_argument(
+    '--json-output', required=True,
+    help='Path to the merged json results file.')
+  return parser.parse_args(args)
+
+
+def main(args):
+  options = parse_args(args)
+
+  inputs = []
+  for input_path in options.json_input:
+    with open(input_path) as f:
+      inputs.append(json.load(f))
+
+  result = merge_test_results(inputs)
+  with open(options.json_output, 'w') as f:
+    json.dump(result, f, sort_keys=True, indent=2)
+
+  print(f'Merged results for {result["num_tests"]} tests '
+        f'and {len(result["failures"])} failures.')
+
+
+if __name__ == '__main__':
+  main(sys.argv[1:])

Tools/transpile_tests/test_merge_results.py

@@ -0,0 +1,75 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import contextlib
+import io
+import json
+import unittest
+
+from pyfakefs import fake_filesystem_unittest
+
+import merge_json_results
+
+
+class TestMergeResults(fake_filesystem_unittest.TestCase):
+
+  @fake_filesystem_unittest.patchfs(allow_root_user=True)
+  def test_full_run(self, fs):
+    with open('/in1.json', 'w') as f:
+      json.dump({
+        'num_tests': 2,
+        'failures': [
+          {'path': 'path/to/failure1', 'output': 'foo'},
+        ]
+      }, f)
+
+    with open('/in2.json', 'w') as f:
+      json.dump({
+        'num_tests': 3,
+        'failures': [
+          {'path': 'path/to/failure2', 'output': 'bar 42\nbar 43'},
+          {'path': 'path/to/failure3', 'output': 'baz'},
+        ]
+      }, f)
+
+    f = io.StringIO()
+    with contextlib.redirect_stdout(f):
+      merge_json_results.main([
+          '--json-input', '/in1.json',
+          '--json-input', '/in2.json',
+          '--json-output', '/output.json',
+      ])
+
+    # Verify the output.
+    self.assertEqual(
+        'Merged results for 5 tests and 3 failures.',
+        f.getvalue().strip())
+
+    # Verify the results written to the json output file.
+    with open('/output.json') as f:
+      actual_results = json.load(f)
+
+    expected_results = {
+      'num_tests': 5,
+      'failures': [
+        {'path': 'path/to/failure1', 'output': 'foo'},
+        {'path': 'path/to/failure2', 'output': 'bar 42\nbar 43'},
+        {'path': 'path/to/failure3', 'output': 'baz'},
+      ],
+    }
+    self.assertEqual(expected_results, actual_results)
+
+
+if __name__ == '__main__':
+  unittest.main()

Tools/transpile_tests/test_transpile_tests.py

@@ -98,8 +98,6 @@ def test_full_run(self, fs):
 
     expected_results = {
       'num_tests': 4,
-      'num_successes': 3,
-      'percent_successes': 75.0,
       'failures': [
         {
           'output': 'Failed!',
@@ -148,8 +146,6 @@ def test_shard_run(self, fs):
 
     expected_results = {
       'num_tests': 2,
-      'num_successes': 1,
-      'percent_successes': 50.0,
       'failures': [
         {
           'output': 'Failed!',

Tools/transpile_tests/transpile_tests.py

@@ -172,15 +172,13 @@ def test_input_gen():
         f'({num_successes} of {num_tests}) test cases.')
   return {
     'num_tests': num_tests,
-    'num_successes': num_successes,
-    'percent_successes': ratio,
     'failures': failures,
   }
 
 
 def write_json_output(path, results):
   with open(path, 'w') as f:
-    json.dump(results, f)
+    json.dump(results, f, sort_keys=True, indent=2)
 
 
 def parse_args(args):