Rewrite the test runner in python

Show details after failed tests, and a final summary.

Display all available information for failed tests (not only in travis).

Stop removing the last line. The header pollutes the diff, but the
last line does’t change often.
Also, testing it makes sense in interactive mode.

Move the smoke test into its own directory.

Makefile

@@ -103,7 +103,7 @@ $(generated_sources): %: %.in Makefile
 .PHONY: test
 
 test: all
-	cd test && ./run-tests.sh
+	./test/run
 
 # This Makefile does not support parallelism (but gprbuild does).
 .NOTPARALLEL:

README.md

@@ -40,10 +40,11 @@ Build-time Dependencies
 
 * GPRBuild
 * gnat
+* python3 (for tests)
 
 On a Debian-like system, you can install these roughly as follows:
 
-    $ apt-get install gprbuild gnat
+    $ apt-get install gprbuild gnat python3
 
 GNAT versions before 4.9 are believed to link against a buggy runtime on
 64-bit platforms, so should be avoided.

test/01_aeneid/expected.txt

@@ -36285,3 +36285,4 @@ recedo, recedere, recessi, recessus  V (3rd)   [XXXAX]
 recede, go back, withdraw, ebb; retreat; retire; move/keep/pass/slip away;
 
 
+=>Blank exits =>

test/02_ius/expected.txt

@@ -3,3 +3,4 @@ nullus, nulla, nullum (gen -ius)  ADJ   [XXXAX]
 no; none, not any; (PRONominal ADJ)
 
 
+=>Blank exits =>

test/03_qualdupes/expected.txt

@@ -22,3 +22,4 @@ ludius, ludi(i)  N (2nd) M   [XDXEO]    uncommon
 dancer; stage performer;
 
 
+=>Blank exits =>

test/run

@@ -0,0 +1,133 @@
+#!/usr/bin/python3
+
+"""Test Whitaker's words."""
+
+import glob
+import os.path
+import shutil
+import subprocess
+import sys
+import tempfile
+
+testdir = os.path.abspath(os.path.dirname(sys.argv[0]))
+
+prog = os.path.join(testdir, '..', 'bin', 'words')
+datadir = os.path.join(testdir, '..')
+for arg_index in range(1, len(sys.argv)):
+    arg = sys.argv[arg_index]
+    if arg.startswith('--prog='):
+        prog = arg[7:]
+    elif arg.startswith('--datadir='):
+        datadir = arg[10:]
+    else:
+        print(sys.argv[0], ': unknown argument:', arg)
+        sys.exit(1)
+
+
+def check(test: str) -> bool:
+    """The test name is a subdirectory in testdir.
+
+    If args.txt exists, each line is a command line arguments.
+
+    If input.txt exists, its content is passed on standard input.
+
+    The standard output must match expected.txt, except that
+    * trailing whitespaces are ignored,
+    * the first 18 lines are ignored in interactive mode (if input.txt
+      exists) because it contains a header, no latin.
+    """
+
+    # Required to test file inclusion.
+    os.chdir(os.path.join(testdir, test))
+
+    args = [prog]
+    args_path = 'args.txt'
+    if os.path.exists(args_path):
+        with open(args_path, encoding='utf-8') as args_fd:
+            args.extend(line.rstrip() for line in args_fd)
+
+    input_path = 'input.txt'
+    if os.path.exists(input_path):
+        with open(input_path, 'rb') as input_fd:
+            input_bytes = input_fd.read()
+    else:
+        input_bytes = b''
+
+    words = subprocess.run(args, input=input_bytes,
+                           capture_output=True, check=False)
+
+    result = True
+
+    if words.returncode != 0:
+        print(f'Test {test}: return code: {words.returncode}')
+        result = False
+
+    if words.stderr != b'':
+        print(f'-- Begin of standard error of {test}')
+        print(words.stderr.decode('utf-8'))
+        print(f'-- End of standard error of {test}')
+        result = False
+
+    expected_path = 'expected.txt'
+    got = words.stdout
+    if input_bytes != b'':
+        # Skip the interactive mode header.
+        got = b'\n'.join(got.split(b'\n')[18:])
+    diff_args = ('diff', '-uZ', expected_path, '-')
+    # This writes the differences on standard output, if any.
+    diff = subprocess.run(diff_args, input=got, check=False)
+    if diff.returncode != 0:
+        print()
+        print()
+        print(f'-- Begin of raw standard output of {test}')
+        print(words.stdout.decode('utf-8'))
+        print(f'-- End of raw standard output of {test} (diff above)')
+        print()
+        print()
+        result = False
+
+    print('Test', test, ':', ('FAIL', 'PASS')[result])
+    return result
+
+
+def run_some_tests() -> dict[str, bool]:
+    """
+    Create a temporary datadir with the test configuration, mostly
+    in order to select some non-interactive input options.  The other
+    files required at run time are copied from HOWTO.txt.
+    """
+
+    results: dict[str, bool] = {}
+
+    with tempfile.TemporaryDirectory() as temp_dir:
+        os.environ['WHITAKERS_WORDS_DATADIR'] = temp_dir
+
+        shutil.copy(os.path.join(testdir, 'WORD.MDV'), temp_dir)
+        for data_file in ('INFLECTS.SEC', 'ADDONS.LAT', 'UNIQUES.LAT',
+                          'DICTFILE.GEN', 'STEMFILE.GEN', 'INDXFILE.GEN',
+                          'EWDSFILE.GEN'):
+            shutil.copy(os.path.join(datadir, data_file), temp_dir)
+
+        # If the initial smoke test fails, don't waste time on other
+        # tests, and just let the whole thing crash.
+        results['smoke'] = check('smoke')
+        if results['smoke']:
+            for test in glob.glob('[0-9][0-9]_*', root_dir=testdir):
+                results[test] = check(test)
+
+    return results
+
+
+def show(results: dict[str, bool]) -> None:
+    """Display a final summary."""
+    if all(results.values()):
+        print('All tests passed')
+    else:
+        print('Some tests failed:')
+        for test, result in results.items():
+            if not result:
+                print(' ', test)
+        sys.exit(1)
+
+
+show(run_some_tests())

test/smoke/args.txt

@@ -0,0 +1 @@
+rem acu tetigisti