Add pyslang/tests/test_syntax_tree_equality.py Python tests (#1214)

pyslang/tests/test_syntax_tree_equality.py

@@ -0,0 +1,104 @@
+"""Basic tests checking that syntax tree equality checks work as expected."""
+
+import pyslang
+
+
+def is_verilog_equal(verilog_left: str, verilog_right: str) -> bool:
+    """Check if two Verilog modules are equivalent.
+
+    Helper function for repeated check in upcoming tests.
+    """
+    ast_left = pyslang.SyntaxTree.fromText(verilog_left)
+    ast_right = pyslang.SyntaxTree.fromText(verilog_right)
+    return (ast_left.root).isEquivalentTo(ast_right.root)
+
+
+def test_is_verilog_equal_when_equal() -> None:
+    """Assert `is_verilog_equal` when the two Verilog modules are equal."""
+    input_1 = """
+        module and_gate (
+            input wire x,
+            input wire y,
+            output wire z
+        );
+            assign z = x & y;
+        endmodule
+    """
+
+    input_2 = """
+        module and_gate (
+            input wire x,
+            input wire y,
+            output wire z
+        );
+            assign z = x & y;
+            // Comment here
+        endmodule
+    """
+
+    assert is_verilog_equal(input_1, input_2) is True
+
+
+def test_is_verilog_equal_when_not_equal() -> None:
+    """Assert `is_verilog_equal` when the two Verilog modules are not equal."""
+    input_1 = """
+        module and_gate (
+            input wire x,
+            input wire y,
+            output wire z
+        );
+            assign z = x & y;
+        endmodule
+    """
+
+    input_2 = """
+        module or_gate (
+            input wire x,
+            input wire y,
+            output wire z
+        );
+            assign z = x | y;
+        endmodule
+    """
+
+    assert is_verilog_equal(input_1, input_2) is False
+
+
+def test_verilog_equality() -> None:
+    """Test that two Verilog modules with minor differences are evaluated as equal."""
+    input_1 = """
+        module and_gate (
+            input wire x,
+            input wire y,
+            output wire z
+        );
+            assign z = x & y;
+        endmodule
+    """
+
+    input_2 = """
+        module and_gate (
+            input wire x,
+            input wire y, // Comment here
+            output wire z
+        );
+            // Comment here
+            assign z = x & y;
+            /* Another comment here */
+        endmodule
+    """
+
+    st1 = pyslang.SyntaxTree.fromText(input_1)
+    st1_again = pyslang.SyntaxTree.fromText(input_1)
+    st1_stripped = pyslang.SyntaxTree.fromText(input_1.strip())
+
+    assert st1.root.isEquivalentTo(st1_again.root)
+    assert st1.root.isEquivalentTo(st1_stripped.root)
+    assert st1_again.root.isEquivalentTo(st1_stripped.root)
+
+    st2 = pyslang.SyntaxTree.fromText(input_2)
+    st2_stripped = pyslang.SyntaxTree.fromText(input_2.strip())
+
+    assert st1_stripped.root.isEquivalentTo(st2.root)
+    assert st1.root.isEquivalentTo(st2.root)
+    assert st1.root.isEquivalentTo(st2_stripped.root)