Add check_path.py test to verify existing path elements are maintained

scripts/check_path.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+# Given a previous path check that the current path
+# contains all the same elements in the same order
+# with no elements removed.
+
+import os
+import sys
+
+
+old_path = sys.argv[1].split(os.pathsep)
+new_path = os.environ['PATH'].split(os.pathsep)
+
+paths_added = [p for p in new_path if p not in old_path]
+paths_preserved = [p for p in new_path if p in old_path]
+
+print('verifying path elemnts have been preserved')
+print('old: %s' % old_path)
+print('new: %s' % new_path)
+
+for p in old_path:
+  if p not in paths_preserved:
+    print('path not reserved: ' + p)
+    sys.exit(1)
+
+# Check that ordering matches too.
+if old_path != paths_preserved:
+  print('preserved paths don\'t match original path:')
+  print('old:')
+  for p in old_path:
+    print(' - ' + p)
+  print('preserved:')
+  for p in paths_preserved:
+    print(' - ' + p)
+  sys.exit(1)

scripts/test.bat

@@ -1,7 +1,10 @@
 :: equivilent of test.sh as windows bat file
 set PATH=%PATH%;%PYTHON_BIN%
-@CALL emsdk install latest
-@CALL emsdk activate latest
-@CALL emsdk_env.bat --build=Release
-@CALL python -c "import sys; print(sys.executable)"
-@CALL emcc.bat -v
+set OLD_PATH=%PATH%
+CALL emsdk install latest
+CALL emsdk activate latest
+CALL emsdk_env.bat --build=Release
+CALL python -c "import sys; print(sys.executable)"
+CALL emcc.bat -v
+:: Check that no path elements were removed
+CALL python scripts/check_path.py "%OLD_PATH%"

scripts/test.sh

@@ -5,10 +5,13 @@ echo "test the standard workflow (as close as possible to how a user would do it
 set -x
 set -e
 
+OLD_PATH=$PATH
 ./emsdk install latest
 ./emsdk activate latest
 source ./emsdk_env.sh --build=Release
 # On mac and windows python3 should be in the path and point to the
 # bundled version.
 which python3
 emcc -v
+# Check that no path elements were removed
+python3 scripts/check_path.py "$OLD_PATH"