depot_tools: add create_temp_file.py

It takes text from stdin and dump the read text to a temp file.

Bug: 428193406
Change-Id: I268dc4905e157d619d1af7d0b96f711f224f39db
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6789063
Reviewed-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Scott Lee <ddoman@chromium.org>

create_temp_file.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+import argparse
+import os
+import sys
+import tempfile
+
+
+def run(prefix=None, suffix=None):
+    """ Reads text from stdin, writes it to a temporary file.
+
+    The path of the temporary file is printed to stdout on success.
+    """
+    try:
+        with tempfile.NamedTemporaryFile(mode='w+',
+                                         delete=False,
+                                         encoding='utf-8',
+                                         prefix=prefix,
+                                         suffix=suffix) as temp_file:
+            for line in sys.stdin:
+                temp_file.write(line)
+            temp_file.flush()
+            temp_file_path = temp_file.name
+
+        print(temp_file_path)
+
+    except Exception as e:
+        print(f"An error occurred: {e}", file=sys.stderr)
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description="Writes stdin to a temporary file and then print the path.",
+    )
+    parser.add_argument('--prefix',
+                        help="Optional prefix for the temporary file name.")
+    parser.add_argument('--suffix',
+                        help="Optional suffix for the temporary file name.")
+    args = parser.parse_args()
+    run(prefix=args.prefix, suffix=args.suffix)

tests/create_temp_file_test.py

@@ -0,0 +1,116 @@
+#!/usr/bin/env vpython3
+# Copyright (c) 2022 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import argparse
+import unittest
+import sys
+import os
+import io
+import tempfile
+from unittest.mock import patch
+
+ROOT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, ROOT_DIR)
+
+import create_temp_file
+
+
+class TestCreateTempFileFromStdin(unittest.TestCase):
+
+    def setUp(self):
+        """Set up test environment: capture stdout and stderr."""
+        self.held_stdout = sys.stdout
+        self.held_stderr = sys.stderr
+        self.new_stdout = io.StringIO()
+        self.new_stderr = io.StringIO()
+        sys.stdout = self.new_stdout
+        sys.stderr = self.new_stderr
+
+    def tearDown(self):
+        """Clean up test environment: restore stdout and stderr."""
+        sys.stdout = self.held_stdout
+        sys.stderr = self.held_stderr
+
+    def _read_content_and_delete_file(self, file_path):
+        """Helper to read content of a temporary file."""
+        with open(file_path, 'r', encoding='utf-8') as f:
+            ret = f.read()
+        os.remove(file_path)
+        return ret
+
+    @patch('sys.stdin', new_callable=io.StringIO)
+    def test_basic_text_input(self, mock_stdin):
+        """Test with basic multi-line text input."""
+        test_content = "Hello, world!\nThis is a test.\n"
+        mock_stdin.write(test_content)
+        mock_stdin.seek(0)  # Rewind the mock stdin to the beginning
+
+        create_temp_file.run()
+
+        # Get the output printed to stdout (the temp file path)
+        output = self.new_stdout.getvalue().strip()
+        self.assertTrue(os.path.exists(output))  # Check if file was created
+
+        # Verify content
+        file_content = self._read_content_and_delete_file(output)
+        self.assertEqual(self.new_stderr.getvalue(), "")  # No errors on stderr
+        self.assertEqual(file_content, test_content)
+
+    @patch('sys.stdin', new_callable=io.StringIO)
+    def test_empty_input(self, mock_stdin):
+        """Test with empty input from stdin."""
+        test_content = ""
+        mock_stdin.write(test_content)
+        mock_stdin.seek(0)
+
+        create_temp_file.run()
+        output = self.new_stdout.getvalue().strip()
+        self.assertTrue(os.path.exists(output))  # File should still be created
+        file_content = self._read_content_and_delete_file(output)
+        self.assertEqual(file_content, test_content)
+        self.assertFalse(os.path.exists(output))
+        self.assertEqual(self.new_stderr.getvalue(), "")
+
+    @patch('sys.stdin', new_callable=io.StringIO)
+    def test_with_prefix(self, mock_stdin):
+        """Test if the --prefix argument is respected."""
+        test_content = "Prefix test content.\n"
+        mock_stdin.write(test_content)
+        mock_stdin.seek(0)
+
+        # Simulate argparse.args
+        mock_args = argparse.Namespace(prefix="myprefix_", suffix=None)
+        with patch('argparse.ArgumentParser.parse_args',
+                   return_value=mock_args):
+            create_temp_file.run(prefix=mock_args.prefix)
+
+        output = self.new_stdout.getvalue().strip()
+        self.assertTrue(os.path.exists(output))
+        self.assertTrue(os.path.basename(output).startswith("myprefix_"))
+        file_content = self._read_content_and_delete_file(output)
+        self.assertEqual(file_content, test_content)
+
+    @patch('sys.stdin', new_callable=io.StringIO)
+    def test_with_suffix(self, mock_stdin):
+        """Test if the --suffix argument is respected."""
+        test_content = "Suffix test content.\n"
+        mock_stdin.write(test_content)
+        mock_stdin.seek(0)
+
+        # Simulate argparse.args
+        mock_args = argparse.Namespace(prefix=None, suffix=".log")
+        with patch('argparse.ArgumentParser.parse_args',
+                   return_value=mock_args):
+            create_temp_file.run(suffix=mock_args.suffix)
+
+        output = self.new_stdout.getvalue().strip()
+        self.assertTrue(os.path.exists(output))
+        self.assertTrue(os.path.basename(output).endswith(".log"))
+        file_content = self._read_content_and_delete_file(output)
+        self.assertEqual(file_content, test_content)
+
+
+if __name__ == '__main__':
+    unittest.main()