Testing: You can now use callables as assertions in some places.

I'm using that to make a few tests more robust against (hopefully irrelevant)
changes in the output.

regressiontest/run-regression.py

@@ -27,13 +27,36 @@
 import contextlib
 import datetime
 import os
+import re
 import subprocess
 import tempfile
 import traceback
 
 
 ####################### Misc. utilities
 
+def _assert_has(assertion, found_str, where):
+ """executes assertion on found_str.
+
+ Assertion can be a
+
+ * str, bytes: the assertion fails if the string isn't in found_str
+ * callable: the assertin fails if callable(found_str) is false.
+ * None: Nothing will be asserted.
+ """
+ if assertion is None:
+ return
+
+ elif isinstance(assertion, (str, bytes)):
+ assert assertion in found_str, f"'{assertion}' missing in {where}"
+
+ elif hasattr(assertion, "__call__"):
+ assert assertion(found_str), f"f({assertion}) is not true in {where}"
+
+ else:
+ assert False, f"Cannot understand assertion: {assertion}"
+
+
 def execute(cmd, check_output=None, input=None):
  """execute a subprocess.Popen-compatible command cmd under supervision.
 
@@ -47,10 +70,11 @@ def execute(cmd, check_output=None, input=None):
  output = subprocess.check_output(cmd, shell=True, input=input,
  stderr=subprocess.STDOUT)
  output = output.decode("utf-8")
- if isinstance(check_output, str):
+ if check_output is not None:
  with open("last-output.txt", "w", encoding="utf-8") as f:
  f.write(output)
- assert check_output in output, f"'{check_output}' missing"
+ _assert_has(check_output, output, cmd)
+
  return output
 
 
@@ -67,7 +91,7 @@ def _assert_for_particles(file_name, assertion, particles):
  content = content.decode("utf-8")
 
  for part in particles:
- assertion(part, content)
+ assertion(part, content, file_name)
 
 
 def assert_in_file(file_name, *particles):
@@ -77,9 +101,7 @@ def assert_in_file(file_name, *particles):
  if particles[0] is a string, content will be utf-8 decoded, else
  we will make assertions about byte strings.
  """
- def _(part, content):
- assert part in content, f"'{part}' not in {file_name}"
- _assert_for_particles(file_name, _, particles)
+ _assert_for_particles(file_name, _assert_has, particles)
 
 
 def assert_not_in_file(file_name, *particles):
@@ -88,8 +110,8 @@ def assert_not_in_file(file_name, *particles):
 
  See assert_in_file for details.
  """
- def _(part, content):
- assert part not in content, f"'{part}' present in {file_name}"
+ def _(part, content, where):
+ assert part not in content, f"'{part}' present in {where}"
  _assert_for_particles(file_name, _, particles)
 
 
@@ -172,7 +194,8 @@ def edit_document_template():
 def test_first_run():
  # Basically, make sure that a very basic LaTeX call works and yields a
  # plausible PDF.
- execute("make", "Latexmk: All targets (Regress.pdf) are up-to-date")
+ execute("make", lambda output: re.search(
+ "Latexmk: All targets (.*?) are up-to-date", output))
  execute("pdftotext Regress.pdf")
 
  assert_in_file("Regress.txt",
@@ -210,7 +233,7 @@ def test_archdiag():
 
  assert_in_file("role_diagram.pdf", b"%PDF-1.5", b"/Kids [ 2 0 R ]")
  assert_in_file("Regress.log",
- "<role_diagram.pdf, id=47, 803.0pt x 602.25pt>")
+ lambda op: re.search(b"<role_diagram.pdf, id=47, .*?pt>", op))
 
 
 def test_extra_macros():