[TECHDEBT] Increase test coverage (#2782)

## Changes
Increase test coverage to avoid failing CI with code changes hat cannot
be unit tested

### Linked issues
None

### Functionality
None

### Tests
- [x] added unit tests

---------

Co-authored-by: Eric Vergnaud <eric.vergnaud@databricks.com>

Author: ericvergnaud

src/databricks/labs/ucx/source_code/python/python_analyzer.py

@@ -90,14 +90,6 @@ def build_inherited_context(self, child_path: Path) -> InheritedContext:
             context.tree.append_globals(globs)
         return context
 
-    def _build_full_tree(self, inherited_context: Tree | None) -> Tree:
-        full_tree = Tree.new_module()
-        if inherited_context is not None:
-            full_tree = full_tree.append_tree(inherited_context)
-            full_tree = full_tree.renumber(-1)
-        tree = Tree.normalize_and_parse(self._python_code)
-        return full_tree.append_tree(tree)
-
     def _parse_and_extract_nodes(self) -> tuple[Tree, list[NodeBase], Iterable[DependencyProblem]]:
         problems: list[DependencyProblem] = []
         tree = Tree.normalize_and_parse(self._python_code)

tests/unit/source_code/test_directfs_access.py

@@ -12,6 +12,8 @@
 def test_crawler_appends_dfsas():
     backend = MockBackend()
     crawler = DirectFsAccessCrawler.for_paths(backend, "schema")
+    existing = list(crawler.snapshot())
+    assert not existing
     dfsas = list(
         DirectFsAccess(
             path=path,

tests/unit/source_code/test_known.py

@@ -1,9 +1,11 @@
 from pathlib import Path
+from typing import cast
 from unittest import mock
 
 import pytest
 
 from databricks.labs.ucx.source_code.known import KnownList
+from databricks.labs.ucx.source_code.path_lookup import PathLookup
 
 
 def test_checks_compatibility():
@@ -21,6 +23,10 @@ def test_checks_compatibility():
     assert os_path.known
     assert not os_path.problems
 
+    other = known.module_compatibility(cast(str, None))
+    assert not other.known
+    assert not other.problems
+
 
 def test_checks_library_compatibility():
     known = KnownList()
@@ -33,6 +39,10 @@ def test_checks_library_compatibility():
     assert s3fs.known
     assert len(s3fs.problems) == 1
 
+    other = known.distribution_compatibility(cast(str, None))
+    assert not other.known
+    assert not other.problems
+
 
 def test_loads_known_json():
     known_json = KnownList._get_known()  # pylint: disable=protected-access
@@ -51,3 +61,19 @@ def test_rebuild_trivial():
     # No-op: the known.json file is already up-to-date
     cwd = Path.cwd()
     KnownList.rebuild(cwd)
+
+
+def test_analyze_dist_info():
+
+    class TestKnownList(KnownList):
+
+        @classmethod
+        def analyze_cachetools_dist_info(cls):
+            path_lookup = PathLookup.from_sys_path(Path.cwd())
+            for library_root in path_lookup.library_roots:
+                for dist_info_folder in library_root.glob("*.dist-info"):
+                    if "cachetools" in dist_info_folder.as_posix():
+                        cls._analyze_dist_info(dist_info_folder, {}, library_root)
+                        return
+
+    TestKnownList.analyze_cachetools_dist_info()

tests/unit/source_code/test_queries.py

@@ -1,3 +1,4 @@
+from unittest import mock
 from unittest.mock import create_autospec
 
 import pytest
@@ -45,3 +46,17 @@ def test_query_liner_refresh_report_writes_query_problems(migration_index, mock_
     assert mock_backend.has_rows_written_for("`test`.query_problems")
     ws.dashboards.list.assert_called_once()
     crawlers.assert_not_called()
+
+
+def test_lints_queries(migration_index, mock_backend) -> None:
+    with mock.patch("databricks.labs.ucx.source_code.queries.Redash") as mocked_redash:
+        query = LegacyQuery(id="123", query="SELECT * from nowhere")
+        mocked_redash.get_queries_from_dashboard.return_value = [query]
+        ws = create_autospec(WorkspaceClient)
+        crawlers = create_autospec(DirectFsAccessCrawler)
+        linter = QueryLinter(ws, migration_index, crawlers, ["1"])
+        linter.refresh_report(mock_backend, inventory_database="test")
+
+        assert mock_backend.has_rows_written_for("`test`.query_problems")
+        ws.dashboards.list.assert_not_called()
+        crawlers.assert_not_called()