acc: add negative test to contains.py

Author: denik

acceptance/bin/contains.py

@@ -1,18 +1,27 @@
 #!/usr/bin/env python3
 import sys
 
-targets = sys.argv[1:]
-assert targets
+must_find = []
+must_not_find = []
+for arg in sys.argv[1:]:
+    if arg.startswith("!"):
+        must_not_find.append(arg[1:])
+    else:
+        must_find.append(arg)
+
 found = set()
 
 for line in sys.stdin:
     sys.stdout.write(line)
-    for t in targets:
+    for t in must_find:
         if t in line:
             found.add(t)
+    for t in must_not_find:
+        if t in line:
+            sys.stderr.write(f"contains error: {t!r} was not expected\n")
 
 sys.stdout.flush()
 
-not_found = set(targets) - found
+not_found = set(must_find) - found
 for item in sorted(not_found):
     sys.stderr.write(f"contains error: {item!r} not found in the output.\n")

acceptance/selftest/contains/output.txt

@@ -1,10 +1,10 @@
 
-=== This should complain about not_found not found, but errcode is zero
+=== This should complain about not_found not found
 >>> python3 ./success.py
 Hello world
 contains error: 'not_found' not found in the output.
 
-=== This should complain about not_found not found, but errcode is propagated
+=== This should complain about not_found not found
 >>> musterr python3 ./failure.py
 Failed script
 contains error: 'not_found' not found in the output.
@@ -13,6 +13,15 @@ contains error: 'not_found' not found in the output.
 >>> python3 ./success.py
 Hello world
 
-=== This should not complain, but errcode is propagated
+=== This should not complain
 >>> musterr python3 ./failure.py
 Failed script
+
+=== This should complain about Hello present in output
+>>> python3 ./success.py
+Hello world
+contains error: 'Hello' was not expected
+
+=== This should not complain
+>>> python3 ./success.py
+Hello world

acceptance/selftest/contains/script

@@ -1,12 +1,17 @@
-title "This should complain about "not_found" not found, but errcode is zero"
+title "This should complain about not_found not found"
 trace python3 ./success.py | contains.py not_found
 
-title "This should complain about "not_found" not found, but errcode is propagated"
-# this has a race between musterr and contains.py output:
+title "This should complain about not_found not found"
 trace musterr python3 ./failure.py | contains.py not_found
 
 title "This should not complain"
 trace python3 ./success.py | contains.py world Hello
 
-title "This should not complain, but errcode is propagated"
+title "This should not complain"
 trace musterr python3 ./failure.py | contains.py Failed
+
+title "This should complain about Hello present in output"
+trace python3 ./success.py | contains.py !Hello
+
+title "This should not complain"
+trace python3 ./success.py | contains.py !not_found