Python: More review suggestions

I could have sworn I added all of them to the batch, but somehow these slipped through.

Co-authored-by: yoff <lerchedahl@gmail.com>
Co-authored-by: Rasmus Wriedt Larsen <rasmuswriedtlarsen@gmail.com>

Author: 3 people

python/ql/lib/semmle/python/dataflow/new/internal/ImportResolution.qll

@@ -78,7 +78,7 @@ module ImportResolution {
     )
     or
     exists(Alias a |
-      defn.asExpr() = [a.getValue(), a.getValue().(ImportMember).getModule()] and
+      defn.asExpr() = [a.getValue().(ImportExpr), a.getValue().(ImportMember).getModule()] and
       a.getAsname().(Name).getId() = name and
       defn.getScope() = m
     )

python/ql/test/experimental/import-resolution/importflow.ql

@@ -27,7 +27,7 @@ private class ImportConfiguration extends DataFlow::Configuration {
 class ResolutionTest extends InlineExpectationsTest {
   ResolutionTest() { this = "ResolutionTest" }
 
-  override string getARelevantTag() { result = "import" }
+  override string getARelevantTag() { result = "prints" }
 
   override predicate hasActualResult(Location location, string element, string tag, string value) {
     exists(DataFlow::PathNode source, DataFlow::PathNode sink, ImportConfiguration config |

python/ql/test/experimental/import-resolution/main.py

@@ -1,4 +1,22 @@
 #! /usr/bin/env python3
+"""
+A slightly complicated test setup. I wanted to both make sure I captured
+the semantics of Python and also the fact that the kinds of global flow
+we expect to see are indeed present.
+
+The code is executable, and prints out both when the execution reaches
+certain files, and also what values are assigned to the various
+attributes that are referenced throughout the program. These values are
+validated in the test as well.
+
+My original version used introspection to avoid referencing attributes
+directly (thus enabling better error diagnostics), but unfortunately
+that made it so that the model couldn't follow what was going on.
+
+The current setup is a bit clunky (and Python's scoping rules makes it
+especially so -- cf. the explicit calls to `globals` and `locals`), but
+I think it does the job okay.
+"""
 
 from __future__ import print_function
 import sys