Add Validators, Utils, and Unit Tests for Data Integrity

src/venvalid/utils_errors.py

@@ -0,0 +1,9 @@
+def pretty_print_error(error: Exception) -> None:
+    """Pretty print errors using rich if available, else fallback to plain text"""
+    try:
+        from rich.console import Console
+
+        console = Console()
+        console.print(f"[bold red]Error:[/bold red] {error}")
+    except ImportError:
+        print(f"Error: {error}")

src/venvalid/validator.py

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+from .errors import EnvSafeError
+
+
+def validate_env_var(name: str, value: str | None):
+    if not value:
+        raise EnvSafeError(f"Missing required environment variable: {name}")
+    return True

tests/test_utils_errors.py

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+import sys
+import types
+
+import src.venvalid.utils_errors as utils_errors
+
+
+class DummyConsole:
+    def __init__(self):
+        self.last_message = None
+
+    def print(self, msg):
+        self.last_message = msg
+
+
+def test_pretty_print_error_with_rich(monkeypatch):
+    dummy_console = DummyConsole()
+
+    fake_rich_pkg = types.ModuleType("rich")
+    fake_rich_pkg.__path__ = []  # mark as package
+
+    fake_console_mod = types.ModuleType("rich.console")
+    setattr(fake_console_mod, "Console", lambda: dummy_console)
+
+    monkeypatch.setitem(sys.modules, "rich", fake_rich_pkg)
+    monkeypatch.setitem(sys.modules, "rich.console", fake_console_mod)
+
+    utils_errors.pretty_print_error(ValueError("boom"))
+
+    assert dummy_console.last_message is not None
+    assert "boom" in dummy_console.last_message
+
+
+def test_pretty_print_error_without_rich(monkeypatch, capsys):
+    monkeypatch.delitem(sys.modules, "rich.console", raising=False)
+    monkeypatch.delitem(sys.modules, "rich", raising=False)
+
+    utils_errors.pretty_print_error(ValueError("fail"))
+
+    out = capsys.readouterr().out
+    assert "Error: fail" in out

tests/test_validator.py

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+import pytest
+
+from src.venvalid.errors import EnvSafeError
+from src.venvalid.validator import validate_env_var
+
+
+def test_validate_env_var_success():
+    assert validate_env_var("API_KEY", "secret") is True
+
+
+def test_validate_env_var_missing():
+    with pytest.raises(EnvSafeError) as exc_info:
+        validate_env_var("API_KEY", None)
+
+    assert "Missing required environment variable: API_KEY" in str(exc_info.value)