test: add config framework unit tests

tests/unit/byteb4rb1e/utils/config/test_config.py

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+"""Unit tests for the config framework."""
+
+from argparse import ArgumentParser, Namespace
+from dataclasses import dataclass
+from pathlib import Path
+
+import pytest
+
+from byteb4rb1e.utils.config import (
+    add_config_arguments,
+    apply_cli_overrides,
+    apply_overrides,
+    ensure_ini,
+    ensure_ini_multi,
+    format_help,
+    format_section,
+    load_ini,
+    resolve_hints,
+)
+
+
+@dataclass
+class SampleConfig:
+    name: str = "default"
+    count: int = 10
+    ratio: float = 0.5
+    enabled: bool = True
+
+
+class TestLoadIni:
+    def test_loads_values(self, tmp_path):
+        ini = tmp_path / "test.ini"
+        ini.write_text(
+            "[sample]\n"
+            "name = custom\n"
+            "count = 42\n"
+            "ratio = 0.75\n"
+        )
+        config = load_ini(SampleConfig, ini)
+        assert config.name == "custom"
+        assert config.count == 42
+        assert config.ratio == 0.75
+        assert config.enabled is True  # default
+
+    def test_missing_section_uses_defaults(self, tmp_path):
+        ini = tmp_path / "test.ini"
+        ini.write_text("[other]\nfoo = bar\n")
+        config = load_ini(SampleConfig, ini)
+        assert config.name == "default"
+        assert config.count == 10
+
+    def test_missing_file_uses_defaults(self, tmp_path):
+        config = load_ini(
+            SampleConfig, tmp_path / "missing.ini"
+        )
+        assert config.name == "default"
+
+    def test_unknown_key_raises(self, tmp_path):
+        ini = tmp_path / "test.ini"
+        ini.write_text("[sample]\nunknown_key = bad\n")
+        with pytest.raises(ValueError, match="unknown_key"):
+            load_ini(SampleConfig, ini)
+
+    def test_custom_section_name(self, tmp_path):
+        ini = tmp_path / "test.ini"
+        ini.write_text("[mysection]\nname = custom\n")
+        config = load_ini(
+            SampleConfig, ini, section="mysection"
+        )
+        assert config.name == "custom"
+
+    def test_comments_ignored(self, tmp_path):
+        ini = tmp_path / "test.ini"
+        ini.write_text(
+            "[sample]\n"
+            "# this is a comment\n"
+            "name = works  # inline comment\n"
+        )
+        config = load_ini(SampleConfig, ini)
+        assert config.name == "works"
+
+
+class TestAddConfigArguments:
+    def test_generates_flags(self):
+        parser = ArgumentParser()
+        add_config_arguments(SampleConfig, parser)
+        args = parser.parse_args(
+            ["--name", "cli", "--count", "99"]
+        )
+        assert args.name == "cli"
+        assert args.count == 99
+
+    def test_defaults_are_none(self):
+        parser = ArgumentParser()
+        add_config_arguments(SampleConfig, parser)
+        args = parser.parse_args([])
+        assert args.name is None
+        assert args.count is None
+
+    def test_underscores_become_dashes(self):
+        @dataclass
+        class DashConfig:
+            my_long_name: str = "x"
+
+        parser = ArgumentParser()
+        add_config_arguments(DashConfig, parser)
+        args = parser.parse_args(
+            ["--my-long-name", "val"]
+        )
+        assert args.my_long_name == "val"
+
+
+class TestApplyCliOverrides:
+    def test_overrides_set_values(self):
+        config = SampleConfig()
+        args = Namespace(name="override", count=None,
+                         ratio=None, enabled=None)
+        result = apply_cli_overrides(config, args)
+        assert result.name == "override"
+        assert result.count == 10  # unchanged
+
+    def test_no_overrides_returns_same(self):
+        config = SampleConfig()
+        args = Namespace(name=None, count=None,
+                         ratio=None, enabled=None)
+        result = apply_cli_overrides(config, args)
+        assert result.name == "default"
+        assert result is config
+
+
+class TestEnsureIni:
+    def test_creates_file_if_missing(self, tmp_path):
+        ini = tmp_path / "new.ini"
+        assert not ini.exists()
+        config = ensure_ini(SampleConfig, ini)
+        assert ini.exists()
+        assert config.name == "default"
+        assert config.count == 10
+
+    def test_created_file_has_all_fields(self, tmp_path):
+        ini = tmp_path / "new.ini"
+        ensure_ini(SampleConfig, ini)
+        content = ini.read_text()
+        assert "name" in content
+        assert "count" in content
+        assert "ratio" in content
+        assert "enabled" in content
+
+    def test_created_file_has_comments(self, tmp_path):
+        ini = tmp_path / "new.ini"
+        ensure_ini(SampleConfig, ini)
+        content = ini.read_text()
+        assert "# name (str)" in content
+        assert "# count (int)" in content
+
+    def test_reads_existing_file(self, tmp_path):
+        ini = tmp_path / "existing.ini"
+        ini.write_text("[sample]\ncount = 42\n")
+        config = ensure_ini(SampleConfig, ini)
+        assert config.count == 42
+
+    def test_does_not_overwrite_existing(self, tmp_path):
+        ini = tmp_path / "existing.ini"
+        ini.write_text("[sample]\ncount = 42\n")
+        ensure_ini(SampleConfig, ini)
+        content = ini.read_text()
+        assert content == "[sample]\ncount = 42\n"
+
+    def test_created_file_is_loadable(self, tmp_path):
+        ini = tmp_path / "new.ini"
+        ensure_ini(SampleConfig, ini)
+        config = load_ini(SampleConfig, ini)
+        assert config.name == "default"
+        assert config.count == 10
+        assert config.ratio == 0.5
+
+
+class TestIntegration:
+    def test_ini_then_cli_override(self, tmp_path):
+        ini = tmp_path / "test.ini"
+        ini.write_text("[sample]\ncount = 42\n")
+        config = load_ini(SampleConfig, ini)
+        assert config.count == 42
+
+        args = Namespace(name=None, count=99,
+                         ratio=None, enabled=None)
+        config = apply_cli_overrides(config, args)
+        assert config.count == 99
+        assert config.name == "default"
+
+    def test_ensure_then_cli_override(self, tmp_path):
+        ini = tmp_path / "new.ini"
+        config = ensure_ini(SampleConfig, ini)
+        assert config.count == 10
+
+        args = Namespace(name=None, count=99,
+                         ratio=None, enabled=None)
+        config = apply_cli_overrides(config, args)
+        assert config.count == 99
+        assert config.name == "default"
+
+        # Config file unchanged
+        reloaded = load_ini(SampleConfig, ini)
+        assert reloaded.count == 10
+
+
+class TestResolveHints:
+    def test_returns_type_dict(self):
+        hints = resolve_hints(SampleConfig)
+        assert hints["name"] is str
+        assert hints["count"] is int
+        assert hints["ratio"] is float
+        assert hints["enabled"] is bool
+
+
+class TestFormatSection:
+    def test_includes_section_header(self):
+        text = format_section(SampleConfig)
+        assert "[sample]" in text
+
+    def test_custom_section_name(self):
+        text = format_section(SampleConfig, "custom")
+        assert "[custom]" in text
+
+    def test_includes_all_fields(self):
+        text = format_section(SampleConfig)
+        assert "name = default" in text
+        assert "count = 10" in text
+        assert "ratio = 0.5" in text
+        assert "enabled = True" in text
+
+    def test_includes_type_comments(self):
+        text = format_section(SampleConfig)
+        assert "# name (str)" in text
+        assert "# count (int)" in text
+
+    def test_is_loadable(self, tmp_path):
+        ini = tmp_path / "test.ini"
+        ini.write_text(format_section(SampleConfig) + "\n")
+        config = load_ini(SampleConfig, ini)
+        assert config.name == "default"
+        assert config.count == 10
+
+
+class TestEnsureIniMulti:
+    def test_creates_file_with_multiple_sections(self, tmp_path):
+        @dataclass
+        class OtherConfig:
+            host: str = "localhost"
+            port: int = 8080
+
+        ini = tmp_path / "multi.ini"
+        ensure_ini_multi([
+            (SampleConfig, None),
+            (OtherConfig, "server"),
+        ], ini)
+
+        content = ini.read_text()
+        assert "[sample]" in content
+        assert "[server]" in content
+        assert "name = default" in content
+        assert "host = localhost" in content
+
+    def test_does_not_overwrite_existing(self, tmp_path):
+        ini = tmp_path / "multi.ini"
+        ini.write_text("[existing]\nfoo = bar\n")
+        ensure_ini_multi([(SampleConfig, None)], ini)
+        content = ini.read_text()
+        assert content == "[existing]\nfoo = bar\n"
+
+    def test_sections_are_loadable(self, tmp_path):
+        @dataclass
+        class DbConfig:
+            url: str = "sqlite:///test.db"
+
+        ini = tmp_path / "multi.ini"
+        ensure_ini_multi([
+            (SampleConfig, None),
+            (DbConfig, "database"),
+        ], ini)
+
+        sample = load_ini(SampleConfig, ini)
+        db = load_ini(DbConfig, ini, section="database")
+        assert sample.name == "default"
+        assert db.url == "sqlite:///test.db"
+
+
+class TestApplyOverrides:
+    def test_applies_dotted_path(self):
+        config = SampleConfig()
+        result = apply_overrides(config, {
+            "provider.name": "custom",
+            "provider.count": "99",
+        }, prefix="provider")
+        assert result.name == "custom"
+        assert result.count == 99
+
+    def test_without_prefix(self):
+        config = SampleConfig()
+        result = apply_overrides(config, {
+            "name": "direct",
+            "count": "42",
+        })
+        assert result.name == "direct"
+        assert result.count == 42
+
+    def test_no_matching_keys_returns_same(self):
+        config = SampleConfig()
+        result = apply_overrides(config, {"other.key": "val"}, prefix="provider")
+        assert result is config
+
+    def test_bool_coercion(self):
+        config = SampleConfig()
+        result = apply_overrides(config, {"enabled": "false"})
+        assert result.enabled is False
+
+    def test_preserves_unset_fields(self):
+        config = SampleConfig()
+        result = apply_overrides(config, {"name": "changed"})
+        assert result.name == "changed"
+        assert result.count == 10  # unchanged
+        assert result.ratio == 0.5  # unchanged
+
+
+class TestFormatHelp:
+    def test_lists_all_fields(self):
+        lines = format_help(SampleConfig)
+        assert len(lines) == 4
+        assert any("name" in l for l in lines)
+        assert any("count" in l for l in lines)
+
+    def test_includes_types(self):
+        lines = format_help(SampleConfig)
+        text = "\n".join(lines)
+        assert "str" in text
+        assert "int" in text
+
+    def test_includes_defaults(self):
+        lines = format_help(SampleConfig)
+        text = "\n".join(lines)
+        assert "default" in text
+        assert "10" in text
+
+    def test_with_prefix(self):
+        lines = format_help(SampleConfig, prefix="provider")
+        assert any("provider.name" in l for l in lines)
+        assert any("provider.count" in l for l in lines)