url/tools/IdnaTestV2-compare.py

# This script can be used to compare IdnaTestV2.json across revisions, with some manual labor. It is
# used primarily for review and to add to IdnaTestV2-removed.json, to ensure we never lose a test.
# (IdnaTestV2.json is the output of IdnaTestV2-parser.py.)

import argparse
import json

def compute_differences():
    data_old = None
    data_new = None
    with open("IdnaTestV2-old.json", "r") as file_handle:
        data_old = json.load(file_handle)

    with open("IdnaTestV2-new.json", "r") as file_handle:
        data_new = json.load(file_handle)

    added_tests = []
    changed_tests = []
    removed_tests = []

    for old_test in data_old:
        if isinstance(old_test, str):
            continue
        found = None
        for new_test in data_new:
            if isinstance(new_test, str):
                continue
            if old_test["input"] == new_test["input"]:
                found = new_test
                break

        if not found:
            # We now exclude ? as it's a forbidden domain code point. This check can be removed in the future.
            if "?" not in old_test["input"]:
                removed_tests.append(old_test)
        # For changed tests we only care about parsing no longer succeeding.
        elif old_test["output"] != found["output"] and old_test["output"]:
            changed_tests.append({ "input": old_test["input"], "output_old": old_test["output"], "output_new": found["output"] })

    for new_test in data_new:
        if isinstance(new_test, str):
            continue
        found = False
        for old_test in data_old:
            if isinstance(old_test, str):
                continue
            if new_test["input"] == old_test["input"]:
                found = True
                break
        if not found:
            added_tests.append(new_test)

    return { "added": added_tests, "changed": changed_tests, "removed": removed_tests }

def main():
    parser = argparse.ArgumentParser(epilog="Thanks for caring about IDNA!")
    group = parser.add_mutually_exclusive_group(required=True)
    group.add_argument("--differences", action="store_true", help="Output the differences")
    group.add_argument("--removed", action="store_true", help="Output the removed tests only")
    args = parser.parse_args()

    differences = compute_differences()

    output = None

    if args.differences:
        output = differences
    elif args.removed:
        output = differences["removed"]

    print(json.dumps(output, sort_keys=True, allow_nan=False, indent=2, separators=(',', ': ')))

main()