CI tests for helper functions + .txt file

Author: ArturU043

tests/data/expected_structure.txt

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+
+File structure of all samples with branch filter '':
+
+---------------------------
+📁 Sample: test_file
+---------------------------
+
+🌳 Tree: background
+   ├── Branches:
+   │   ├──  branch1 ; dtype: AsDtype('>f8')
+   │   ├──  branch2 ; dtype: AsDtype('>f8')
+
+🌳 Tree: signal
+   ├── Branches:
+   │   ├──  branch1 ; dtype: AsDtype('>f8')

tests/test_file_peeking.py

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+# Copyright (c) 2025, IRIS-HEP
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# * Redistributions of source code must retain the above copyright notice, this
+#   list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright notice,
+#   this list of conditions and the following disclaimer in the documentation
+#   and/or other materials provided with the distribution.
+#
+# * Neither the name of the copyright holder nor the names of its
+#   contributors may be used to endorse or promote products derived from
+#   this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+import pytest
+import uproot 
+import awkward as ak
+import os
+import sys
+import numpy as np
+from servicex_analysis_utils import file_peeking
+import types
+import servicex 
+import filecmp
+
+
+@pytest.fixture
+def build_test_samples(tmp_path):
+
+    test_path = str(tmp_path / "test_file1.root")
+    # example data for two branches
+    tree_data1 = {
+    "branch1": np.ones(100),
+    "branch2": np.zeros(100)
+    }
+    tree_data2 = {
+    "branch1": np.ones(10),
+    }
+
+    # Create tmp .root files
+    with uproot.create(test_path) as file:
+        file["background"] = tree_data1
+        file["signal"] = tree_data2
+
+    return test_path
+
+# Test helper functions: run_query, print_structure_from_str
+def test_encoding(build_test_samples,tmp_path, capsys):
+
+    path=build_test_samples
+    query_output=file_peeking.run_query(path)
+    
+    #Check return types
+    assert isinstance(query_output, ak.Array), "run_query() does not produce an awkward.Array"
+    encoded_result=query_output[0]
+    assert isinstance(encoded_result, str), "run_query array content is not str"
+    
+    #Check result
+    expected_result= (
+        "Tree: background; TBranch: branch1 ; dtype: AsDtype('>f8'), TBranch: branch2 ; dtype: AsDtype('>f8')"
+        "\nTree: signal; TBranch: branch1 ; dtype: AsDtype('>f8')"
+    )    
+    assert encoded_result == expected_result
+
+    # Produce servicex.deliver() like dict
+    tree_data= {"branch" : query_output}
+    with uproot.create(tmp_path / "encoded.root") as file:
+        file["servicex"]= tree_data
+    assert os.path.exists(tmp_path / "encoded.root"), f"servicex-like test file not found."
+    deliver_dict={"test_file":[str(tmp_path / "encoded.root")]}
+
+    
+    ## Test decoding structure formating
+    # save_to_txt
+    file_peeking.print_structure_from_str(deliver_dict,save_to_txt=True)
+    out_txt="samples_structure.txt"
+    assert os.path.exists(out_txt), "save_to_txt arg not producing files"
+
+    with open(out_txt, "r", encoding="utf-8") as f:
+        written_str = f.read()
+
+    # direct return
+    output_str=file_peeking.print_structure_from_str(deliver_dict)
+
+    # do_print
+    file_peeking.print_structure_from_str(deliver_dict,do_print=True)
+    captured = capsys.readouterr()
+    
+    # Check if all returns match 
+    assert captured.out[0:-1] == written_str == output_str , "saved, printed and direct return formats are different"
+    
+    # Compare with expected return
+    test_txt="tests/data/expected_structure.txt"
+    assert filecmp.cmp(out_txt, test_txt), "Formatted str does not match expected return"
+
+    # Test filter_branch
+    filtered_str=file_peeking.print_structure_from_str(deliver_dict,filter_branch="branch2")
+    assert "branch1" not in filtered_str, "filter_branch argument is not removing branch1"
+
+
+# Test user-facing function errors:
+