Convert wrapper test binary to Python.

This removes a dependency on the non-builtin Go rules.

elisp/BUILD

@@ -348,7 +348,10 @@ py_library(
     name = "runfiles",
     srcs = ["runfiles.py"],
     srcs_version = "PY3",
-    visibility = ["//emacs:__pkg__"],
+    visibility = [
+        "//emacs:__pkg__",
+        "//tests/wrap:__pkg__",
+    ],
     deps = ["@bazel_tools//tools/python/runfiles"],
 )
 

tests/wrap/BUILD

@@ -12,27 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
-
-go_library(
-    name = "go_default_library",
-    testonly = 1,
-    srcs = ["main.go"],
-    importpath = "github.com/phst/rules_elisp/tests/wrap",
-    visibility = ["//visibility:private"],
-    deps = [
-        "@com_github_google_go_cmp//cmp:go_default_library",
-        "@com_github_phst_runfiles//:go_default_library",
-    ],
-)
-
-go_binary(
+py_binary(
     name = "wrap",
     testonly = 1,
-    out = select({
-        "@platforms//os:windows": "wrap.exe",
-        "//conditions:default": "wrap",
-    }),
-    embed = [":go_default_library"],
+    srcs = ["wrap.py"],
+    python_version = "PY3",
+    srcs_version = "PY3",
     visibility = ["//elisp:__pkg__"],
+    deps = ["//elisp:runfiles"],
 )

tests/wrap/wrap.py

@@ -0,0 +1,96 @@
+# Copyright 2020, 2021 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.
+
+"""Binary wrap is a test helper program for //elisp:binary_test, which see."""
+
+import argparse
+import json
+import os
+import pathlib
+import unittest
+import sys
+from typing import Any, Dict, List
+
+from phst_rules_elisp.elisp import runfiles
+
+def _main() -> None:
+    print('Args:', sys.argv)
+    print('Environment:', os.environ)
+    parser = argparse.ArgumentParser(allow_abbrev=False)
+    parser.add_argument('--manifest', type=pathlib.Path, required=True)
+    parser.add_argument('rest', nargs='+')
+    args = parser.parse_args()
+    run_files = runfiles.Runfiles()
+    output_file = pathlib.PurePath(
+        r'C:\Temp\output.dat' if os.name == 'nt' else '/tmp/output.dat')
+
+    class Test(unittest.TestCase):
+        """Unit tests for the command line and manifest."""
+
+        maxDiff = 5000
+
+        def test_args(self) -> None:
+            """Test that the Emacs command line is as expected."""
+            got = args.rest
+            want = ['--quick', '--batch']
+	    # The load path setup depends on whether we use manifest-based or
+	    # directory-based runfiles.
+            try:
+                directory = run_files.resolve(
+                    pathlib.PurePosixPath('phst_rules_elisp'))
+            except FileNotFoundError:
+                # Manifest-based runfiles.
+                want += [
+                    '--load=' + str(run_files.resolve(pathlib.PurePosixPath(
+                        'phst_rules_elisp/elisp/runfiles/runfiles.elc'))),
+                    '--funcall=elisp/runfiles/install-handler',
+		    '--directory=/bazel-runfile:phst_rules_elisp',
+                ]
+            else:
+                # Directory-based runfiles.
+                want.append('--directory=' + str(directory))
+            want += [
+                '--option',
+                str(run_files.resolve(pathlib.PurePosixPath(
+                    'phst_rules_elisp/elisp/binary.cc'))),
+                ' \t\n\r\f äα𝐴🐈\'\\"',
+                '/:' + str(output_file),
+            ]
+            self.assertListEqual(got, want)
+
+        def test_manifest(self) -> None:
+            """Test the manifest."""
+            got = json.loads(args.manifest.read_text(encoding='utf-8'))
+            want = {
+                'root':        'RUNFILES_ROOT',
+                'tags':        ['local', 'mytag'],
+		'loadPath':    ['phst_rules_elisp'],
+		'inputFiles':  ['phst_rules_elisp/elisp/binary.cc',
+                                'phst_rules_elisp/elisp/binary.h'],
+		'outputFiles': [str(output_file)],
+            }  # type: Dict[str, Any]
+            for var in (got, want):
+                files = var.get('inputFiles', [])  # type: List[str]
+                for i, file in enumerate(files):
+                    file = pathlib.PurePosixPath(file)
+                    if not file.is_absolute():
+                        files[i] = str(run_files.resolve(file))
+            self.assertDictEqual(got, want)
+
+    tests = unittest.defaultTestLoader.loadTestsFromTestCase(Test)
+    if not unittest.TextTestRunner().run(tests).wasSuccessful():
+        raise ValueError('incorrect arguments')
+
+if __name__ == '__main__':
+    _main()