diff --git a/test_equation_parser.py b/test_equation_parser.py
deleted file mode 100644
index 3095bfd..0000000
--- a/test_equation_parser.py
+++ /dev/null
@@ -1,42 +0,0 @@
-
-from equation_parser import parse_equation, EquationValidationError
-import sympy as sp
-
-
-def test_basic_equation():
-    expression = parse_equation("x**2 + y**2")
-    assert expression == sp.Symbol("x")**2 + sp.Symbol("y")**2
-
-
-def test_caret_notation():
-    expression = parse_equation("x^2 + y^2")
-    assert expression == sp.Symbol("x")**2 + sp.Symbol("y")**2
-
-
-def test_math_function():
-    expression = parse_equation("sin(x) + cos(y)")
-    assert expression == sp.sin(sp.Symbol("x")) + sp.cos(sp.Symbol("y"))
-
-
-def test_invalid_variable():
-    try:
-        parse_equation("x**2 + z**2")
-        assert False, "Expected validation error"
-    except EquationValidationError:
-        pass
-
-
-def test_unsafe_input():
-    try:
-        parse_equation("print(x)")
-        assert False, "Expected validation error"
-    except EquationValidationError:
-        pass
-
-
-def test_empty_input():
-    try:
-        parse_equation("")
-        assert False, "Expected validation error"
-    except EquationValidationError:
-        pass
diff --git a/tests/test_equation_parser.py b/tests/test_equation_parser.py
new file mode 100644
index 0000000..423d465
--- /dev/null
+++ b/tests/test_equation_parser.py
@@ -0,0 +1,81 @@
+from equation_parser import x, y
+import pytest
+import sympy as sp
+
+from equation_parser import parse_equation, EquationValidationError
+
+
+def test_basic_equation():
+    expression = parse_equation("x**2 + y**2")
+    assert expression == sp.Symbol("x")**2 + sp.Symbol("y")**2
+
+
+def test_caret_notation():
+    expression = parse_equation("x^2 + y^2")
+    assert expression == sp.Symbol("x")**2 + sp.Symbol("y")**2
+
+
+def test_math_function():
+    expression = parse_equation("sin(x) + cos(y)")
+    assert expression == sp.sin(sp.Symbol("x")) + sp.cos(sp.Symbol("y"))
+
+
+def test_invalid_variable():
+    with pytest.raises(EquationValidationError):
+        parse_equation("x**2 + z**2")
+
+
+def test_unsafe_input():
+    with pytest.raises(EquationValidationError):
+        parse_equation("print(x)")
+
+
+def test_empty_input():
+    with pytest.raises(EquationValidationError):
+        parse_equation("")
+
+
+def test_allowed_constants():
+    expression = parse_equation("x + pi + E")
+    assert expression == x + sp.pi + sp.E
+
+
+def test_all_supported_functions():
+    expression = parse_equation(
+        "tan(x) + exp(y) + log(x) + sqrt(y) + abs(x)"
+    )
+
+    assert expression == (
+        sp.tan(x) + sp.exp(y) + sp.log(x)
+        + sp.sqrt(y) + sp.Abs(x)
+    )
+
+
+def test_unsupported_function():
+    with pytest.raises(EquationValidationError):
+        parse_equation("factorial(x)")
+
+
+def test_unsupported_operator():
+    with pytest.raises(EquationValidationError):
+        parse_equation("x // y")
+
+
+def test_multiple_function_arguments():
+    with pytest.raises(EquationValidationError):
+        parse_equation("sin(x, y)")
+
+
+def test_exponent_limit():
+    with pytest.raises(EquationValidationError):
+        parse_equation("x**101")
+
+
+def test_boolean_input():
+    with pytest.raises(EquationValidationError):
+        parse_equation("True + x")
+
+
+def test_invalid_syntax():
+    with pytest.raises(EquationValidationError):
+        parse_equation("x + * y")