log: test: Add a pytest for logging

Add a test which tries out various filters and options to make sure that
logging works as expected.

Signed-off-by: Simon Glass <sjg@chromium.org>

MAINTAINERS

@@ -317,6 +317,7 @@ T:	git git://git.denx.de/u-boot.git
 F:	common/log.c
 F:	cmd/log.c
 F:	test/log/log_test.c
+F:	test/py/tests/test_log.py
 
 MICROBLAZE
 M:	Michal Simek <monstr@monstr.eu>

test/py/tests/test_log.py

+# Copyright (c) 2016, Google Inc.
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+# U-Boot Verified Boot Test
+
+"""
+This tests U-Boot logging. It uses the 'log test' command with various options
+and checks that the output is correct.
+"""
+
+import pytest
+
+LOGL_FIRST, LOGL_WARNING, LOGL_INFO = (0, 4, 6)
+
+@pytest.mark.buildconfigspec('log')
+def test_log(u_boot_console):
+    """Test that U-Boot logging works correctly."""
+    def check_log_entries(lines, mask, max_level=LOGL_INFO):
+        """Check that the expected log records appear in the output
+
+        Args:
+            lines: iterator containing lines to check
+            mask: bit mask to select which lines to check for:
+                bit 0: standard log line
+                bit 1: _log line
+            max_level: maximum log level to expect in the output
+        """
+        for i in range(max_level):
+            if mask & 1:
+                assert 'log %d' % i == lines.next()
+            if mask & 3:
+                assert '_log %d' % i == lines.next()
+
+    def run_test(testnum):
+        """Run a particular test number (the 'log test' command)
+
+        Args:
+            testnum: Test number to run
+        Returns:
+            iterator containing the lines output from the command
+        """
+
+        with cons.log.section('basic'):
+           output = u_boot_console.run_command('log test %d' % testnum)
+        split = output.replace('\r', '').splitlines()
+        lines = iter(split)
+        assert 'test %d' % testnum == lines.next()
+        return lines
+
+    def test0():
+        lines = run_test(0)
+        check_log_entries(lines, 3)
+
+    def test1():
+        lines = run_test(1)
+        check_log_entries(lines, 3)
+
+    def test2():
+        lines = run_test(2)
+
+    def test3():
+        lines = run_test(3)
+        check_log_entries(lines, 2)
+
+    def test4():
+        lines = run_test(4)
+        assert next(lines, None) == None
+
+    def test5():
+        lines = run_test(5)
+        check_log_entries(lines, 2)
+
+    def test6():
+        lines = run_test(6)
+        check_log_entries(lines, 3)
+
+    def test7():
+        lines = run_test(7)
+        check_log_entries(lines, 3, LOGL_WARNING)
+
+    def test8():
+        lines = run_test(8)
+        check_log_entries(lines, 3)
+
+    def test9():
+        lines = run_test(9)
+        check_log_entries(lines, 3)
+
+    # TODO(sjg@chromium.org): Consider structuring this as separate tests
+    cons = u_boot_console
+    test0()
+    test1()
+    test2()
+    test3()
+    test4()
+    test5()
+    test6()
+    test7()
+    test8()
+    test9()