test_func_pattern_fixing.py

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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# tests/tests_formatter/test_func_pattern_fixing.py
 
"""
Tests for func pattern fixing.
 
Purpose
-------
Verify that the formatter correctly fixes missing func = "..." patterns.
 
Responsibilities
----------------
- Test addition of func variable to functions with _dbg() calls.
- Test skipping of functions without _dbg() calls.
- Test skipping of functions that already have the pattern.
- Test proper indentation.
 
Diagnostics
-----------
Domain: TESTS.FORMATTER
Levels:
    L2 — test lifecycle
    L3 — test case setup
    L4 — AST parsing and pattern insertion
 
Contracts
---------
- func variable must be first statement in function.
- Pattern is skipped if already present.
- Functions without _dbg() are never modified.
"""
 
import ast
import pytest
from pathlib import Path
 
from oct.formatter.oct_format import (
    fix_func_pattern,
    FormatterContext,
    _detect_indent_style,
)
 
 
def _make_nontrivial(content: str) -> str:
    """Pad content to be > 20 lines."""
    lines = content.split('\n')
    while len(lines) < 22:
        lines.append("# padding")
    return '\n'.join(lines)
 
 
def test_add_func_pattern_single_function(temp_project_root: Path, formatter_ctx_fix: FormatterContext):
    """Test adding func pattern to a single function."""
    test_file = temp_project_root / "test_single_func.py"
    content = _make_nontrivial(
        "#!/usr/bin/env python3\n"
        "# -*- coding: utf-8 -*-\n"
        "# test.py\n"
        "\n"
        "from oc_diagnostics import _dbg\n"
        "\n"
        "def my_func():\n"
        "    _dbg('TEST', 'start')\n"
        "    return 42\n"
    )
    test_file.write_text(content, encoding="utf-8")
 
    changed, new_content, messages = fix_func_pattern(test_file, content, formatter_ctx_fix)
 
    assert changed is True
    assert 'func = "my_func"' in new_content
 
 
def test_add_func_pattern_multiple_functions(temp_project_root: Path, formatter_ctx_fix: FormatterContext):
    """Test adding func pattern to multiple functions."""
    test_file = temp_project_root / "test_multi_func.py"
    content = _make_nontrivial(
        "#!/usr/bin/env python3\n"
        "# -*- coding: utf-8 -*-\n"
        "# test.py\n"
        "\n"
        "from oc_diagnostics import _dbg\n"
        "\n"
        "def foo():\n"
        "    _dbg('TEST', 'foo')\n"
        "\n"
        "def bar():\n"
        "    _dbg('TEST', 'bar')\n"
    )
    test_file.write_text(content, encoding="utf-8")
 
    changed, new_content, messages = fix_func_pattern(test_file, content, formatter_ctx_fix)
 
    assert changed is True
    assert 'func = "foo"' in new_content
    assert 'func = "bar"' in new_content
 
 
def test_skip_function_without_dbg(temp_project_root: Path, formatter_ctx_fix: FormatterContext):
    """Test that functions without _dbg() are not modified."""
    test_file = temp_project_root / "test_no_dbg.py"
    content = _make_nontrivial(
        "#!/usr/bin/env python3\n"
        "# -*- coding: utf-8 -*-\n"
        "# test.py\n"
        "\n"
        "from oc_diagnostics import _dbg\n"
        "\n"
        "def no_dbg():\n"
        "    '''No diagnostics.'''\n"
        "    return 42\n"
        "\n"
        "def has_dbg():\n"
        "    _dbg('TEST', 'test')\n"
    )
    test_file.write_text(content, encoding="utf-8")
 
    changed, new_content, messages = fix_func_pattern(test_file, content, formatter_ctx_fix)
 
    assert changed is True
    assert 'func = "has_dbg"' in new_content
    assert 'func = "no_dbg"' not in new_content
 
 
def test_skip_existing_pattern(temp_project_root: Path, formatter_ctx_fix: FormatterContext):
    """Test that existing func patterns are not duplicated."""
    test_file = temp_project_root / "test_existing_pattern.py"
    content = _make_nontrivial(
        "#!/usr/bin/env python3\n"
        "# -*- coding: utf-8 -*-\n"
        "# test.py\n"
        "\n"
        "from oc_diagnostics import _dbg\n"
        "\n"
        "def my_func():\n"
        "    func = 'my_func'\n"
        "    _dbg('TEST', func, 'start', 2)\n"
    )
    test_file.write_text(content, encoding="utf-8")
 
    changed, _, messages = fix_func_pattern(test_file, content, formatter_ctx_fix)
 
    assert changed is False
 
 
def test_skip_trivial_files(temp_project_root: Path, formatter_ctx_fix: FormatterContext):
    """Test that trivial files are skipped."""
    test_file = temp_project_root / "test_trivial_func.py"
    content = (
        "def foo():\n"
        "    _dbg('TEST', 'test')\n"
    )
    test_file.write_text(content, encoding="utf-8")
 
    changed, _, messages = fix_func_pattern(test_file, content, formatter_ctx_fix)
 
    assert changed is False
 
 
# ============================================================
# OI-425: indentation style detection and tab preservation
# ============================================================
 
 
def test_detect_indent_style_tabs_dominant():
    """``_detect_indent_style`` returns '\\t' when tabs dominate."""
    lines = [
        "def foo():",
        "\treturn 1",
        "\tfor i in range(3):",
        "\t\tprint(i)",
        "    stray = 1",  # one space-indented line — still minority
    ]
    assert _detect_indent_style(lines) == "\t"
 
 
def test_detect_indent_style_spaces_dominant():
    """``_detect_indent_style`` returns '    ' when spaces dominate."""
    lines = [
        "def foo():",
        "    return 1",
        "    for i in range(3):",
        "        print(i)",
    ]
    assert _detect_indent_style(lines) == "    "
 
 
def test_detect_indent_style_ignores_blank_lines():
    """Blank lines must not affect the tally."""
    lines = ["", "\n", "   ", "\tcode", "\tcode2"]
    assert _detect_indent_style(lines) == "\t"
 
 
def test_fix_func_pattern_preserves_tabs(
    temp_project_root: Path, formatter_ctx_fix: FormatterContext,
) -> None:
    """A tab-indented file receives a tab-indented ``func = "..."`` line."""
    test_file = temp_project_root / "test_tabs.py"
    content = _make_nontrivial(
        "#!/usr/bin/env python3\n"
        "# -*- coding: utf-8 -*-\n"
        "# test.py\n"
        "\n"
        "from oc_diagnostics import _dbg\n"
        "\n"
        "def my_func():\n"
        "\t_dbg('TEST', 'start')\n"
        "\treturn 42\n"
    )
    test_file.write_text(content, encoding="utf-8")
 
    changed, new_content, _ = fix_func_pattern(
        test_file, content, formatter_ctx_fix,
    )
 
    assert changed is True
    assert '\tfunc = "my_func"' in new_content
    # No space-indented injection mixed into the tab file.
    assert '    func = "my_func"' not in new_content
    # Output must remain valid Python.
    ast.parse(new_content)
 
 
def test_fix_func_pattern_preserves_spaces(
    temp_project_root: Path, formatter_ctx_fix: FormatterContext,
) -> None:
    """Baseline: a space-indented file still receives space injection."""
    test_file = temp_project_root / "test_spaces.py"
    content = _make_nontrivial(
        "#!/usr/bin/env python3\n"
        "# -*- coding: utf-8 -*-\n"
        "# test.py\n"
        "\n"
        "from oc_diagnostics import _dbg\n"
        "\n"
        "def my_func():\n"
        "    _dbg('TEST', 'start')\n"
        "    return 42\n"
    )
    test_file.write_text(content, encoding="utf-8")
 
    changed, new_content, _ = fix_func_pattern(
        test_file, content, formatter_ctx_fix,
    )
 
    assert changed is True
    assert '    func = "my_func"' in new_content
    ast.parse(new_content)
 
 
def test_fix_func_pattern_tab_indented_class_method(
    temp_project_root: Path, formatter_ctx_fix: FormatterContext,
) -> None:
    """A class method in a tab-indented file gets a ``\\t\\t`` injection."""
    test_file = temp_project_root / "test_tabs_class.py"
    content = _make_nontrivial(
        "#!/usr/bin/env python3\n"
        "# -*- coding: utf-8 -*-\n"
        "# test.py\n"
        "\n"
        "from oc_diagnostics import _dbg\n"
        "\n"
        "class Thing:\n"
        "\tdef run(self):\n"
        "\t\t_dbg('TEST', 'run')\n"
        "\t\treturn 1\n"
    )
    test_file.write_text(content, encoding="utf-8")
 
    changed, new_content, _ = fix_func_pattern(
        test_file, content, formatter_ctx_fix,
    )
 
    assert changed is True
    assert '\t\tfunc = "run"' in new_content
    ast.parse(new_content)