[lldb] Add assertState function to the API test suite

Add a function to make it easier to debug a test failure caused by an
unexpected state.

Currently, tests are using assertEqual which results in a cryptic error
message: "AssertionError: 5 != 10". Even when a test provides a message
to make it clear why a particular state is expected, you still have to
figure out which of the two was the expected state, and what the other
value corresponds to.

We have a function in lldbutil that helps you convert the state number
into a user readable string. This patch adds a wrapper around
assertEqual specifically for comparing states and reporting better error
messages.

The aforementioned error message now looks like this: "AssertionError:
stopped (5) != exited (10)". If the user provided a message, that
continues to get printed as well.

Differential revision: https://reviews.llvm.org/D127355

1 files changed, 11 insertions, 3 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/lldbtest.py b/lldb/packages/Python/lldbsuite/test/lldbtest.py
index 5c536f4..c3dc2a9 100644
--- a/lldb/packages/Python/lldbsuite/test/lldbtest.py
+++ b/lldb/packages/Python/lldbsuite/test/lldbtest.py
@@ -519,9 +519,9 @@ class Base(unittest2.TestCase):
         # /abs/path/to/packages/group/subdir/mytest.py -> group/subdir
         lldb_test_src = configuration.test_src_root
         if not test_file.startswith(lldb_test_src):
-          raise Exception(
-              "Test file '%s' must reside within lldb_test_src "
-              "(which is '%s')." % (test_file, lldb_test_src))
+            raise Exception(
+                "Test file '%s' must reside within lldb_test_src "
+                "(which is '%s')." % (test_file, lldb_test_src))
         return os.path.dirname(os.path.relpath(test_file, start=lldb_test_src))
 
     def TraceOn(self):
@@ -2474,6 +2474,14 @@ FileCheck output:
             self.fail(self._formatMessage(msg,
                 "'{}' is not success".format(error)))
 
+    """Assert two states are equal"""
+    def assertState(self, first, second, msg=None):
+        if first != second:
+            error = "{} ({}) != {} ({})".format(
+                lldbutil.state_type_to_str(first), first,
+                lldbutil.state_type_to_str(second), second)
+            self.fail(self._formatMessage(msg, error))
+
     def createTestTarget(self, file_path=None, msg=None,
                          load_dependent_modules=True):
         """