Add --dry-run mode for metadata and schedule output

Add a local runner dry-run mode that prints runtime metadata and the
generated schedule without executing tests.

Also route the option through docker -> sbin runner and document it in
README files.

Author: kaste

README.md

@@ -152,6 +152,7 @@ Useful options:
 - `--coverage`
 - `--failfast`
 - `--reload-package-on-testing` (default: off)
+- `--dry-run` (only print runtime metadata and schedule)
 - `--scheduler-delay-ms 0` (default)
 - `--refresh-cache` (re-bootstrap cached `/root` state)
 - `--refresh-image` (rebuild local Docker image)

docker/README.md

@@ -67,6 +67,15 @@ ut-run-tests . --refresh-cache
 ut-run-tests . --refresh
 ```
 
+## Dry run (metadata and schedule only)
+
+Use `--dry-run` to print runner metadata (including detected Sublime
+Text and Package Control versions) plus the generated schedule.
+
+```sh
+ut-run-tests . --dry-run
+```
+
 ## Run a single test file
 
 ```sh

docker/run_tests.py

@@ -82,6 +82,7 @@ def main(argv: list[str] | None = None) -> int:
         coverage=args.coverage,
         failfast=args.failfast,
         reload_package_on_testing=args.reload_package_on_testing,
+        dry_run=args.dry_run,
         tests_dir=tests_dir,
         pattern=pattern,
     )
@@ -133,6 +134,11 @@ def parse_args(argv: list[str] | None) -> argparse.Namespace:
         default=0,
         help="Delay before running scheduled tests inside Sublime (default: 0).",
     )
+    test_group.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="Only print runtime metadata and schedule.",
+    )
 
     docker_group = parser.add_argument_group("docker options")
     docker_group.add_argument(
@@ -182,6 +188,9 @@ def parse_args(argv: list[str] | None) -> argparse.Namespace:
     if args.refresh_cache and not args.cache_volume:
         parser.error("--refresh-cache requires a cache volume (omit --no-cache-volume)")
 
+    if args.dry_run and (args.refresh or args.refresh_image or args.refresh_cache):
+        parser.error("--dry-run cannot be combined with --refresh* options")
+
     return args
 
 
@@ -330,6 +339,7 @@ def build_docker_run_command(
     coverage: bool,
     failfast: bool,
     reload_package_on_testing: bool,
+    dry_run: bool,
     tests_dir: str | None,
     pattern: str | None,
 ) -> list[str]:
@@ -359,6 +369,9 @@ def build_docker_run_command(
     if reload_package_on_testing:
         command.append("--reload-package-on-testing")
 
+    if dry_run:
+        command.append("--dry-run")
+
     if tests_dir:
         command.extend(["--tests-dir", tests_dir])
 

sbin/run_tests.py

@@ -207,7 +207,7 @@ def detect_package_control_version():
     return str(version) if version else None
 
 
-def main(default_schedule_info):
+def main(default_schedule_info, dry_run=False):
     package_under_test = default_schedule_info['package']
     output_dir = os.path.join(UT_OUTPUT_DIR_PATH, package_under_test)
     output_file = os.path.join(output_dir, "result")
@@ -217,6 +217,13 @@ def main(default_schedule_info):
 
     print_runtime_metadata()
 
+    if dry_run:
+        create_dir_if_not_exists(output_dir)
+        delete_file_if_exists(output_file)
+        delete_file_if_exists(coverage_file)
+        create_schedule(package_under_test, output_file, default_schedule_info)
+        return
+
     for i in range(3):
         create_dir_if_not_exists(output_dir)
         delete_file_if_exists(output_file)
@@ -256,6 +263,7 @@ def main(default_schedule_info):
     parser.add_option('--tests-dir')
     parser.add_option('--failfast', action='store_true')
     parser.add_option('--reload-package-on-testing', action='store_true')
+    parser.add_option('--dry-run', action='store_true')
 
     options, remainder = parser.parse_args()
 
@@ -286,4 +294,4 @@ def main(default_schedule_info):
     if options.reload_package_on_testing:
         default_schedule_info['reload_package_on_testing'] = True
 
-    main(default_schedule_info)
+    main(default_schedule_info, dry_run=options.dry_run)