Close #22175: Improve test_faulthandler readability with dedent.

Patch written by Xavier de Gaye.

Lib/test/test_faulthandler.py

@@ -10,6 +10,7 @@ from test import support, script_helper
 from test.script_helper import assert_python_ok
 import tempfile
 import unittest
+from textwrap import dedent
 
 try:
     import threading
@@ -47,6 +48,7 @@ class FaultHandlerTests(unittest.TestCase):
         build, and replace "Current thread 0x00007f8d8fbd9700" by "Current
         thread XXX".
         """
+        code = dedent(code).strip()
         with support.SuppressCrashReport():
             process = script_helper.spawn_python('-c', code)
         stdout, stderr = process.communicate()
@@ -76,15 +78,15 @@ class FaultHandlerTests(unittest.TestCase):
         else:
             header = 'Stack (most recent call first)'
         regex = """
-^Fatal Python error: {name}
+            ^Fatal Python error: {name}
 
-{header}:
+            {header}:
               File "<string>", line {lineno} in <module>
-""".strip()
-        regex = regex.format(
+            """
+        regex = dedent(regex.format(
             lineno=line_number,
             name=name_regex,
-            header=re.escape(header))
+            header=re.escape(header))).strip()
         if other_regex:
             regex += '|' + other_regex
         output, exitcode = self.get_output(code, filename)
@@ -96,29 +98,29 @@ class FaultHandlerTests(unittest.TestCase):
                      "the first page of memory is a mapped read-only on AIX")
     def test_read_null(self):
         self.check_fatal_error("""
-import faulthandler
-faulthandler.enable()
-faulthandler._read_null()
-""".strip(),
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._read_null()
+            """,
             3,
             # Issue #12700: Read NULL raises SIGILL on Mac OS X Lion
             '(?:Segmentation fault|Bus error|Illegal instruction)')
 
     def test_sigsegv(self):
         self.check_fatal_error("""
-import faulthandler
-faulthandler.enable()
-faulthandler._sigsegv()
-""".strip(),
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._sigsegv()
+            """,
             3,
             'Segmentation fault')
 
     def test_sigabrt(self):
         self.check_fatal_error("""
-import faulthandler
-faulthandler.enable()
-faulthandler._sigabrt()
-""".strip(),
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._sigabrt()
+            """,
             3,
             'Aborted')
 
@@ -126,10 +128,10 @@ faulthandler._sigabrt()
                      "SIGFPE cannot be caught on Windows")
     def test_sigfpe(self):
         self.check_fatal_error("""
-import faulthandler
-faulthandler.enable()
-faulthandler._sigfpe()
-""".strip(),
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._sigfpe()
+            """,
             3,
             'Floating point exception')
 
@@ -137,10 +139,10 @@ faulthandler._sigfpe()
                      "need faulthandler._sigbus()")
     def test_sigbus(self):
         self.check_fatal_error("""
-import faulthandler
-faulthandler.enable()
-faulthandler._sigbus()
-""".strip(),
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._sigbus()
+            """,
             3,
             'Bus error')
 
@@ -148,18 +150,18 @@ faulthandler._sigbus()
                      "need faulthandler._sigill()")
     def test_sigill(self):
         self.check_fatal_error("""
-import faulthandler
-faulthandler.enable()
-faulthandler._sigill()
-""".strip(),
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._sigill()
+            """,
             3,
             'Illegal instruction')
 
     def test_fatal_error(self):
         self.check_fatal_error("""
-import faulthandler
-faulthandler._fatal_error(b'xyz')
-""".strip(),
+            import faulthandler
+            faulthandler._fatal_error(b'xyz')
+            """,
             2,
             'xyz')
 
@@ -170,52 +172,52 @@ faulthandler._fatal_error(b'xyz')
                      'need faulthandler._stack_overflow()')
     def test_stack_overflow(self):
         self.check_fatal_error("""
-import faulthandler
-faulthandler.enable()
-faulthandler._stack_overflow()
-""".strip(),
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._stack_overflow()
+            """,
             3,
             '(?:Segmentation fault|Bus error)',
             other_regex='unable to raise a stack overflow')
 
     def test_gil_released(self):
         self.check_fatal_error("""
-import faulthandler
-faulthandler.enable()
-faulthandler._read_null(True)
-""".strip(),
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._read_null(True)
+            """,
             3,
             '(?:Segmentation fault|Bus error|Illegal instruction)')
 
     def test_enable_file(self):
         with temporary_filename() as filename:
             self.check_fatal_error("""
-import faulthandler
-output = open({filename}, 'wb')
-faulthandler.enable(output)
-faulthandler._sigsegv()
-""".strip().format(filename=repr(filename)),
+                import faulthandler
+                output = open({filename}, 'wb')
+                faulthandler.enable(output)
+                faulthandler._sigsegv()
+                """.format(filename=repr(filename)),
                 4,
                 'Segmentation fault',
                 filename=filename)
 
     def test_enable_single_thread(self):
         self.check_fatal_error("""
-import faulthandler
-faulthandler.enable(all_threads=False)
-faulthandler._sigsegv()
-""".strip(),
+            import faulthandler
+            faulthandler.enable(all_threads=False)
+            faulthandler._sigsegv()
+            """,
             3,
             'Segmentation fault',
             all_threads=False)
 
     def test_disable(self):
         code = """
-import faulthandler
-faulthandler.enable()
-faulthandler.disable()
-faulthandler._sigsegv()
-""".strip()
+            import faulthandler
+            faulthandler.enable()
+            faulthandler.disable()
+            faulthandler._sigsegv()
+            """
         not_expected = 'Fatal Python error'
         stderr, exitcode = self.get_output(code)
         stder = '\n'.join(stderr)
@@ -283,20 +285,20 @@ faulthandler._sigsegv()
         Raise an error if the output doesn't match the expected format.
         """
         code = """
-import faulthandler
+            import faulthandler
 
-def funcB():
+            def funcB():
                 if {has_filename}:
                     with open({filename}, "wb") as fp:
                         faulthandler.dump_traceback(fp, all_threads=False)
                 else:
                     faulthandler.dump_traceback(all_threads=False)
 
-def funcA():
+            def funcA():
                 funcB()
 
-funcA()
-""".strip()
+            funcA()
+            """
         code = code.format(
             filename=repr(filename),
             has_filename=bool(filename),
@@ -327,13 +329,13 @@ funcA()
         func_name = 'x' * (maxlen + 50)
         truncated = 'x' * maxlen + '...'
         code = """
-import faulthandler
+            import faulthandler
 
-def {func_name}():
+            def {func_name}():
                 faulthandler.dump_traceback(all_threads=False)
 
-{func_name}()
-""".strip()
+            {func_name}()
+            """
         code = code.format(
             func_name=func_name,
         )
@@ -353,18 +355,18 @@ def {func_name}():
         Raise an error if the output doesn't match the expected format.
         """
         code = """
-import faulthandler
-from threading import Thread, Event
-import time
+            import faulthandler
+            from threading import Thread, Event
+            import time
 
-def dump():
+            def dump():
                 if {filename}:
                     with open({filename}, "wb") as fp:
                         faulthandler.dump_traceback(fp, all_threads=True)
                 else:
                     faulthandler.dump_traceback(all_threads=True)
 
-class Waiter(Thread):
+            class Waiter(Thread):
                 # avoid blocking if the main thread raises an exception.
                 daemon = True
 
@@ -377,13 +379,13 @@ class Waiter(Thread):
                     self.running.set()
                     self.stop.wait()
 
-waiter = Waiter()
-waiter.start()
-waiter.running.wait()
-dump()
-waiter.stop.set()
-waiter.join()
-""".strip()
+            waiter = Waiter()
+            waiter.start()
+            waiter.running.wait()
+            dump()
+            waiter.stop.set()
+            waiter.join()
+            """
         code = code.format(filename=repr(filename))
         output, exitcode = self.get_output(code, filename)
         output = '\n'.join(output)
@@ -392,17 +394,17 @@ waiter.join()
         else:
             lineno = 10
         regex = """
-^Thread 0x[0-9a-f]+ \(most recent call first\):
-(?:  File ".*threading.py", line [0-9]+ in [_a-z]+
-){{1,3}}  File "<string>", line 23 in run
+            ^Thread 0x[0-9a-f]+ \(most recent call first\):
+            (?:  File ".*threading.py", line [0-9]+ in [_a-z]+
+            ){{1,3}}  File "<string>", line 23 in run
               File ".*threading.py", line [0-9]+ in _bootstrap_inner
               File ".*threading.py", line [0-9]+ in _bootstrap
 
-Current thread XXX \(most recent call first\):
+            Current thread XXX \(most recent call first\):
               File "<string>", line {lineno} in dump
               File "<string>", line 28 in <module>$
-""".strip()
-        regex = regex.format(lineno=lineno)
+            """
+        regex = dedent(regex.format(lineno=lineno)).strip()
         self.assertRegex(output, regex)
         self.assertEqual(exitcode, 0)
 
@@ -423,10 +425,10 @@ Current thread XXX \(most recent call first\):
         """
         timeout_str = str(datetime.timedelta(seconds=TIMEOUT))
         code = """
-import faulthandler
-import time
+            import faulthandler
+            import time
 
-def func(timeout, repeat, cancel, file, loops):
+            def func(timeout, repeat, cancel, file, loops):
                 for loop in range(loops):
                     faulthandler.dump_traceback_later(timeout, repeat=repeat, file=file)
                     if cancel:
@@ -434,18 +436,18 @@ def func(timeout, repeat, cancel, file, loops):
                     time.sleep(timeout * 5)
                     faulthandler.cancel_dump_traceback_later()
 
-timeout = {timeout}
-repeat = {repeat}
-cancel = {cancel}
-loops = {loops}
-if {has_filename}:
+            timeout = {timeout}
+            repeat = {repeat}
+            cancel = {cancel}
+            loops = {loops}
+            if {has_filename}:
                 file = open({filename}, "wb")
-else:
+            else:
                 file = None
-func(timeout, repeat, cancel, file, loops)
-if file is not None:
+            func(timeout, repeat, cancel, file, loops)
+            if file is not None:
                 file.close()
-""".strip()
+            """
         code = code.format(
             timeout=TIMEOUT,
             repeat=repeat,
@@ -512,45 +514,45 @@ if file is not None:
         """
         signum = signal.SIGUSR1
         code = """
-import faulthandler
-import os
-import signal
-import sys
+            import faulthandler
+            import os
+            import signal
+            import sys
 
-def func(signum):
+            def func(signum):
                 os.kill(os.getpid(), signum)
 
-def handler(signum, frame):
+            def handler(signum, frame):
                 handler.called = True
-handler.called = False
+            handler.called = False
 
-exitcode = 0
-signum = {signum}
-unregister = {unregister}
-chain = {chain}
+            exitcode = 0
+            signum = {signum}
+            unregister = {unregister}
+            chain = {chain}
 
-if {has_filename}:
+            if {has_filename}:
                 file = open({filename}, "wb")
-else:
+            else:
                 file = None
-if chain:
+            if chain:
                 signal.signal(signum, handler)
-faulthandler.register(signum, file=file,
+            faulthandler.register(signum, file=file,
                                   all_threads={all_threads}, chain={chain})
-if unregister:
+            if unregister:
                 faulthandler.unregister(signum)
-func(signum)
-if chain and not handler.called:
+            func(signum)
+            if chain and not handler.called:
                 if file is not None:
                     output = file
                 else:
                     output = sys.stderr
                 print("Error: signal handler not called!", file=output)
                 exitcode = 1
-if file is not None:
+            if file is not None:
                 file.close()
-sys.exit(exitcode)
-""".strip()
+            sys.exit(exitcode)
+            """
         code = code.format(
             filename=repr(filename),
             has_filename=bool(filename),