diff --git a/lineapy/transformer/node_transformer.py b/lineapy/transformer/node_transformer.py
index 691b5253d..843704657 100644
--- a/lineapy/transformer/node_transformer.py
+++ b/lineapy/transformer/node_transformer.py
@@ -569,21 +569,11 @@ def visit_Subscript(self, node: ast.Subscript) -> CallNode:
         args = [self.visit(node.value)]
         index = node.slice
         args.append(self.visit(index))
-        if isinstance(node.ctx, ast.Load):
-            return self.tracer.call(
-                self.tracer.lookup_node(GET_ITEM),
-                self.get_source(node),
-                *args,
-            )
-        elif isinstance(node.ctx, ast.Del):
-            raise NotImplementedError(
-                "Subscript with ctx=ast.Del() not supported."
-            )
-        else:
-            raise ValueError(
-                "Subscript with ctx=ast.Store() should have been handled by"
-                " visit_Assign."
-            )
+        return self.tracer.call(
+            self.tracer.lookup_node(GET_ITEM),
+            self.get_source(node),
+            *args,
+        )
 
     def visit_Attribute(self, node: ast.Attribute) -> CallNode:
 
diff --git a/lineapy/transformer/source_giver.py b/lineapy/transformer/source_giver.py
index de13459b3..a7286cf29 100644
--- a/lineapy/transformer/source_giver.py
+++ b/lineapy/transformer/source_giver.py
@@ -2,9 +2,6 @@
 
 
 class SourceGiver:
-    def __init__(self):
-        pass
-
     def transform(self, nodes: ast.Module) -> None:
         """
         This call should only happen once asttoken has run its magic
@@ -26,31 +23,3 @@ def transform(self, nodes: ast.Module) -> None:
                 node.end_col_offset = node.last_token.end[1]  # type: ignore
                 # if isinstance(node, ast.ListComp):
                 node.col_offset = node.first_token.start[1]  # type: ignore
-
-    def transform_inhouse(self, nodes: ast.Module) -> None:
-        curr_line_start: int = -1
-        curr_line_offset: int = -1
-        prev_line_start: int = -1
-        prev_line_offset: int = -1
-        prev_node = None
-        node: ast.AST
-        # TODO check if the ast type is a Module instead of simply relying on mypy
-        for node in ast.walk(nodes):
-            if not hasattr(node, "lineno"):
-                continue
-
-            curr_line_start = node.lineno
-            curr_line_offset = node.col_offset
-            if prev_node is not None:
-                prev_node.end_lineno = max(  # type: ignore
-                    prev_line_start, curr_line_start - 1
-                )
-                if prev_line_start == curr_line_start:
-                    prev_node.end_col_offset = max(
-                        prev_line_offset, curr_line_offset - 1
-                    )
-                else:
-                    prev_node.end_col_offset = -1
-            prev_node = node
-            prev_line_start = curr_line_start
-            prev_line_offset = curr_line_offset
diff --git a/requirements.txt b/requirements.txt
index 0a3bac3eb..4495a6a1b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,8 +1,7 @@
 alabaster==0.7.12
 altair==4.2.0
-anyio==3.4.0
+anyio==3.5.0
 appnope==0.1.2
-argcomplete==2.0.0
 argon2-cffi==21.3.0
 argon2-cffi-bindings==21.2.0
 astor==0.8.1
@@ -27,7 +26,7 @@ coveralls==3.3.1
 cramjam==2.5.0
 cycler==0.11.0
 debugpy==1.5.1
-decorator==5.1.0
+decorator==5.1.1
 defusedxml==0.7.1
 distlib==0.3.4
 docopt==0.6.2
@@ -39,16 +38,16 @@ fastparquet==0.7.2
 filelock==3.4.2
 flake8==4.0.1
 fonttools==4.28.5
-fsspec==2021.11.1
+fsspec==2022.1.0
 graphviz==0.19.1
 greenlet==1.1.2
-identify==2.4.1
+identify==2.4.4
 idna==3.3
 imagesize==1.3.0
 importlib-metadata==4.2.0
 importlib-resources==5.4.0
 iniconfig==1.1.1
-ipykernel==6.6.1
+ipykernel==6.7.0
 ipython==7.31.0
 ipython-genutils==0.2.0
 isort==5.10.1
@@ -56,13 +55,13 @@ jedi==0.18.1
 Jinja2==3.0.3
 joblib==1.1.0
 json5==0.9.6
-jsonschema==4.3.3
+jsonschema==4.4.0
 jupyter-client==7.1.0
 jupyter-core==4.9.1
-jupyter-server==1.13.1
-jupyterlab==3.2.5
+jupyter-server==1.13.3
+jupyterlab==3.2.8
 jupyterlab-pygments==0.1.2
-jupyterlab-server==2.10.2
+jupyterlab-server==2.10.3
 kiwisolver==1.3.2
 MarkupSafe==2.0.1
 matplotlib==3.5.1
@@ -70,23 +69,23 @@ matplotlib-inline==0.1.3
 mccabe==0.6.1
 mistune==0.8.4
 mock==4.0.3
-mypy==0.910
+mypy==0.931
 mypy-extensions==0.4.3
-nbclassic==0.3.4
-nbclient==0.5.9
+nbclassic==0.3.5
+nbclient==0.5.10
 nbconvert==6.4.0
 nbformat==5.1.3
 nbval==0.9.6
 nest-asyncio==1.5.4
 networkx==2.6.3
 nodeenv==1.6.0
-notebook==6.4.6
+notebook==6.4.7
 numpy==1.21.5
 packaging==21.3
 pandas==1.3.5
 pandocfilters==1.5.0
 parso==0.8.3
-path==16.2.0
+path==16.3.0
 path.py==12.5.0
 pathspec==0.9.0
 pdbpp==0.10.3
@@ -106,7 +105,7 @@ pycodestyle==2.8.0
 pycparser==2.21
 pydantic==1.9.0
 pyflakes==2.4.0
-Pygments==2.11.1
+Pygments==2.11.2
 PyOpenGL==3.1.5
 pyparsing==3.0.6
 pyrepl==0.9.0
@@ -123,7 +122,7 @@ pytz==2021.3
 PyYAML==6.0
 pyzmq==22.3.0
 requests==2.27.1
-rich==10.16.2
+rich==11.0.0
 scikit-learn==1.0.2
 scipy==1.7.3
 scour==0.38.2
@@ -154,10 +153,10 @@ tomli==1.2.3
 toolz==0.11.2
 tornado==6.1
 traitlets==5.1.1
-typed-ast==1.4.3
-types-PyYAML==6.0.1
+typed-ast==1.5.1
+types-PyYAML==6.0.3
 typing_extensions==4.0.1
-urllib3==1.26.7
+urllib3==1.26.8
 virtualenv==20.13.0
 wcwidth==0.2.5
 webencodings==0.5.1
diff --git a/setup.py b/setup.py
index 70950630c..4d3b6949a 100644
--- a/setup.py
+++ b/setup.py
@@ -80,7 +80,7 @@ def version(path):
             "flake8",
             "fastparquet",
             "syrupy==1.4.5",
-            "mypy<0.920",
+            "mypy",
             "isort",
             "pytest",
             "matplotlib",
diff --git a/tests/unit/transformer/test_node_transformer.py b/tests/unit/transformer/test_node_transformer.py
new file mode 100644
index 000000000..14502940d
--- /dev/null
+++ b/tests/unit/transformer/test_node_transformer.py
@@ -0,0 +1,211 @@
+# Setting up for mypy to ignore this file
+# This file uses mocks which have dynamically defined functions.
+# this does not sit well with mypy who needs to know what functions a class has
+# type:ignore
+import ast
+import sys
+
+import asttokens
+import pytest
+from mock import MagicMock, patch
+
+from lineapy.transformer.node_transformer import NodeTransformer, transform
+from lineapy.transformer.source_giver import SourceGiver
+
+
+def _get_ast_node(code):
+    node = ast.parse(code)
+    if sys.version_info < (3, 8):  # give me endlines!
+        asttokens.ASTTokens(code, parse=False, tree=node)
+        SourceGiver().transform(node)
+
+    return node
+
+
+@patch(
+    "lineapy.transformer.node_transformer.NodeTransformer",
+)
+def test_transform_fn(nt_mock: MagicMock):
+    """
+    Test that the transform function calls the NodeTransformer
+    """
+    mocked_tracer = MagicMock()
+    source_location = MagicMock()
+    transform("x = 1", source_location, mocked_tracer)
+    nt_mock.assert_called_once_with("x = 1", source_location, mocked_tracer)
+    mocked_tracer.db.commit.assert_called_once()
+    # TODO - test that source giver is called only for 3.7 and below
+
+
+class TestNodeTransformer:
+    nt: NodeTransformer
+
+    basic_tests_list = [
+        ("a[2:3]", "Slice", 2),
+        ("a[2:3:2]", "Slice", 2),
+        ("a[2:3]", "Subscript", 2),
+        ("a.x", "Attribute", 1),
+        ("{'a': 1}", "Dict", 1),
+        ("a < b", "Compare", 1),
+        ("a not in []", "Compare", 3),
+        ("a + b", "BinOp", 1),
+        ("a or b", "BoolOp", 1),
+        ("[1,2]", "List", 1),
+        # set is xfailing right now
+        # ("{1,2}", "Set", 1),
+        # tuple eventually calls tracer.call but we've mocked out the whole thing
+        ("(1,2)", "Tuple", 0),
+        ("not True", "UnaryOp", 1),
+        ("assert True", "Assert", 1),
+        ("fn(*args)", "Expr", 1),
+        ("fn(*args)", "Call", 1),
+        ("fn(*args)", "Starred", 1),
+        ("fn(*args)", "Name", 1),
+        ("print(*'mystring')", "Starred", 1),
+        # calls tracer.trace_import but this list checks for tracer.call calls
+        ("import math", "Import", 0),
+        # calls tracer.trace_import but this list checks for tracer.call calls
+        # TODO - importfrom calls transform_utils which should really be mocked out and
+        # tested on their own, in true spirit of unit testing
+        ("from math import sqrt", "ImportFrom", 0),
+        ("a, b = (1,2)", "Assign", 2),
+        ("lambda x: x + 10", "Lambda", 1),
+    ]
+
+    # TODO handle visit_Name as its own test
+    # TODO module
+    basic_test_ids = [
+        "slice",
+        "slice_with_step",
+        "subscript",
+        "attribute",
+        "dict",
+        "compare",
+        "compare_notin",
+        "binop",
+        "boolop",
+        "list",
+        # "set",
+        "tuple",
+        "unaryop",
+        "assert",
+        "expr",
+        "call",
+        "starred",
+        "name",
+        "starred_str",
+        "import",
+        "import_from",
+        "assign_tuple",
+        "lambda",
+    ]
+
+    if sys.version_info < (3, 8):
+        basic_tests_list += (("10", "Num", 0),)
+        # extslice does not call tracer.call but it contains a slice node.
+        # that along with subscript will result in two calls
+        basic_tests_list += (("a[:,3]", "ExtSlice", 2),)
+        basic_test_ids += ["num"]
+        basic_test_ids += ["extslice"]
+    else:
+        # this will break with 3.7
+        basic_tests_list += (("10", "Constant", 0),)
+        basic_tests_list += (("a[:,3]", "Slice", 2),)
+        basic_test_ids += ["constant"]
+        basic_test_ids += ["slice_with_ext"]
+
+    basic_tests = ("code, visitor, call_count", basic_tests_list)
+
+    @pytest.fixture(autouse=True)
+    def before_everything(self):
+        nt = NodeTransformer(
+            "", MagicMock(), MagicMock()  # SourceCodeLocation(0, 0, 0, 0)
+        )
+        assert nt is not None
+        self.nt = nt
+
+    def test_lambda_executes_as_expression(self):
+        self.nt._exec_expression = MagicMock()
+        self.nt._exec_statement = MagicMock()
+
+        # this inits an ast.Module containing one expression whose value is a ast.lambda
+        test_node = _get_ast_node("lambda x: x + 10")
+        lambda_node = test_node.body[0].value
+        self.nt.generic_visit(lambda_node)
+        self.nt._exec_statement.assert_not_called()
+        self.nt._exec_expression.assert_called_once()
+
+    def test_assign_executes(self):
+        test_node = _get_ast_node("a = 10")
+        self.nt.visit_Assign = MagicMock()
+        self.nt.visit(test_node.body[0])
+        self.nt.visit_Assign.assert_called_once_with(test_node.body[0])
+
+    def test_assign_calls_tracer_assign(self):
+        self.nt.get_source = MagicMock()
+        test_node = _get_ast_node("a = 10")
+        tracer = self.nt.tracer
+        self.nt.visit(test_node.body[0])
+        tracer.assign.assert_called_once_with("a", tracer.literal.return_value)
+
+    @pytest.mark.parametrize(
+        "code",
+        ["a[3]=10", "a.x =10"],
+        ids=["assign_subscript", "assign_attribute"],
+    )
+    def test_assign_subscript_attribute_calls_tracer_assign(self, code):
+        self.nt.get_source = MagicMock()
+        test_node = _get_ast_node(code)
+        tracer = self.nt.tracer
+        self.nt.visit(test_node.body[0])
+        tracer.call.assert_called_once_with(
+            tracer.lookup_node.return_value,
+            self.nt.get_source.return_value,
+            tracer.lookup_node.return_value,
+            tracer.literal.return_value,
+            tracer.literal.return_value,
+        )
+
+    def test_visit_delete_executes(self):
+        test_node = _get_ast_node("del a")
+        with pytest.raises(NotImplementedError):
+            self.nt.visit_Delete(test_node.body[0])
+
+        self.nt.visit_Delete = MagicMock()
+        self.nt.visit(test_node.body[0])
+        self.nt.visit_Delete.assert_called_once_with(test_node.body[0])
+
+    @pytest.mark.parametrize(
+        "code", ["del a[3]", "del a.x"], ids=["delitem", "delattr"]
+    )
+    def test_visit_delete_subscript_attribute_calls_tracer_call(self, code):
+        self.nt.get_source = MagicMock()
+        test_node = _get_ast_node(code)
+        tracer = self.nt.tracer
+        self.nt.visit(test_node.body[0])
+        tracer.call.assert_called_once_with(
+            tracer.lookup_node.return_value,
+            self.nt.get_source.return_value,
+            tracer.lookup_node.return_value,
+            tracer.literal.return_value,
+        )
+
+    # catch all for any ast nodes that do not have if conditions and/or very little logic
+
+    @pytest.mark.parametrize(*basic_tests, ids=basic_test_ids)
+    def test_code_visited_calls_tracer_call(self, code, visitor, call_count):
+        self.nt._get_code_from_node = MagicMock()
+        test_node = _get_ast_node(code)
+        self.nt.visit(test_node)
+        # doing this so that we can select which function in tracer gets called.
+        # might be overkill though so leaving it at this
+        tracer_fn = getattr(self.nt.tracer, "call")
+        assert tracer_fn.call_count == call_count
+
+    @pytest.mark.parametrize(*basic_tests, ids=basic_test_ids)
+    def test_code_visits_right_visitor(self, code, visitor, call_count):
+        test_node = _get_ast_node(code)
+        self.nt.__setattr__("visit_" + visitor, MagicMock())
+        nt_visitor = self.nt.__getattribute__("visit_" + visitor)
+        self.nt.visit(test_node)
+        nt_visitor.assert_called_once()
diff --git a/tests/unit/test_source_giver.py b/tests/unit/transformer/test_source_giver.py
similarity index 63%
rename from tests/unit/test_source_giver.py
rename to tests/unit/transformer/test_source_giver.py
index 28d9a31cf..6e2d16500 100644
--- a/tests/unit/test_source_giver.py
+++ b/tests/unit/transformer/test_source_giver.py
@@ -6,6 +6,8 @@
 
 from lineapy.transformer.source_giver import SourceGiver
 
+# from astpretty import pprint
+
 
 @pytest.mark.parametrize(
     "code,lineno",
@@ -25,17 +27,18 @@ def test_source_giver_adds_end_lineno(code, lineno):
     if sys.version_info >= (3, 8):
         pytest.skip("SourceGiver not invoked for Python 3.8+")
     import asttokens
-    from astpretty import pprint
 
     tree = ast.parse(code)
+    # ensure that the end_lineno is not available and fetching it raises exceptions
     with pytest.raises(AttributeError):
         print(tree.body[0].end_lineno)
 
+    # now we invoke the SourceGiver and add end_linenos in 2 steps - first we run the tree thr asttokens
     asttokens.ASTTokens(code, parse=False, tree=tree)
-    pprint(tree)
-    print(tree.body[0].last_token)
+    # double check that the line numbers cooked up by asttokens are correct
     assert tree.body[0].last_token.end[0] == lineno
 
+    # and in step 2, run the tree thr SourceGiver and copy the asttokens's token values
+    # so that the tree looks like 3.8+ tree with all the end_linenos etc
     SourceGiver().transform(tree)
     assert tree.body[0].end_lineno == lineno
-    print(tree)