python: add tests for module import

- `--max-import-depth=3` to give points-to a chance
- `not_root` dir to force namespace package logic
- add usage in `example.py` to get files extracted

Author: yoff

python/ql/test/experimental/library-tests/CallGraph-implicit-init/example.py

@@ -16,7 +16,13 @@
 
 from foo.bar.a import afunc
 from foo_explicit.bar.a import explicit_afunc
+from not_root.baz.foo import foo_func
+from not_root.baz.bar.a import afunc as afunc2
 
 afunc() # $ pt,tt="foo/bar/a.py:afunc"
 
 explicit_afunc() # $ pt,tt="foo_explicit/bar/a.py:explicit_afunc"
+
+foo_func() # $ pt,tt="not_root/baz/foo.py:foo_func"
+
+afunc2() # $ pt,tt="not_root/baz/bar/a.py:afunc"

python/ql/test/experimental/library-tests/CallGraph-implicit-init/foo/bar/a.py

@@ -1,3 +1,6 @@
 def afunc():
-  print("afunc called")
-  return 1
+    print("afunc called")
+    return 1
+
+from foo.foo import foo_func
+foo_func() # $ pt,tt="foo/foo.py:foo_func"

python/ql/test/experimental/library-tests/CallGraph-implicit-init/foo/foo.py

@@ -0,0 +1,2 @@
+def foo_func():
+    print("foo_func called")

python/ql/test/experimental/library-tests/CallGraph-implicit-init/foo_explicit/bar/a.py

@@ -1,3 +1,6 @@
 def explicit_afunc():
-  print("explicit_afunc called")
-  return 1
+    print("explicit_afunc called")
+    return 1
+
+from foo_explicit.foo_explicit import foo_explicit_func
+foo_explicit_func() # $ pt,tt="foo_explicit/foo_explicit.py:foo_explicit_func"

python/ql/test/experimental/library-tests/CallGraph-implicit-init/foo_explicit/foo_explicit.py

@@ -0,0 +1,2 @@
+def foo_explicit_func():
+    print("foo_explicit_func called")

python/ql/test/experimental/library-tests/CallGraph-implicit-init/not_root/baz/bar/a.py

@@ -0,0 +1,6 @@
+def afunc():
+    print("afunc called")
+    return 1
+
+from baz.foo import foo_func
+foo_func() # $ MISSING: pt,tt="baz/foo.py:foo_func"

python/ql/test/experimental/library-tests/CallGraph-implicit-init/not_root/baz/foo.py

@@ -0,0 +1,2 @@
+def foo_func():
+    print("foo_func called")

python/ql/test/experimental/library-tests/CallGraph-implicit-init/options

@@ -1 +1 @@
-semmle-extractor-options: --max-import-depth=1 --lang=3
+semmle-extractor-options: --max-import-depth=3 --lang=3