allow reading test environment from python mocks

This allows requesting environment variable values set in the C++ test
code, from python mock code. Use case is cross-checking test
results against values expected by the host side part of the test.

tests/device/libraries/BSTest/Makefile

@@ -14,7 +14,7 @@ $(PYTHON_ENV_DIR):
 	. $(PYTHON_ENV_DIR)/bin/activate && pip install -r requirements.txt
 
 test: $(TEST_EXECUTABLE) $(PYTHON_ENV_DIR)
-	. $(PYTHON_ENV_DIR)/bin/activate && python runner.py -e $(TEST_EXECUTABLE)
+	. $(PYTHON_ENV_DIR)/bin/activate && python runner.py -e $(TEST_EXECUTABLE) -m test/test.py
 
 $(TEST_EXECUTABLE): test/test.cpp
 	g++ -std=c++11 -Isrc -o $@ test/test.cpp

tests/device/libraries/BSTest/mock_decorators.py

@@ -26,3 +26,19 @@ def teardown(test_name):
 		func_env['teardown'] = func_wrapper
 		return func_wrapper
 	return decorator
+
+def setenv(test_env, key, value):
+    if 'env' not in test_env:
+        test_env['env'] = []
+    test_env['env'] += [(key, value)]
+
+def request_env(test_env, key):
+	return test_env['request_env'](key)
+
+def get_all_envs(test_name):
+	global env
+	if test_name not in env:
+		return None
+	if 'env' not in env[test_name]:
+		return None
+	return env[test_name]['env']

tests/device/libraries/BSTest/runner.py

@@ -93,19 +93,27 @@ class BSTestRunner(object):
                 self.sp.logfile = test_output
                 print('running test "{}"'.format(name))
                 if should_update_env:
-                    res = self.update_env()
+                    res = self.update_env(self.env_vars)
                     if res != BSTestRunner.SUCCESS:
                         print('failed to set environment variables')
                         break;
                     should_update_env = False
                 if name in self.mocks:
                     debug_print('setting up mocks')
+                    self.mocks[name]['request_env'] = self.request_env
                     self.mocks[name]['setup']()
+                    extra_env = mock_decorators.get_all_envs(name)
+                    if extra_env is not None:
+                        self.update_env(extra_env)
                 t_start = time.time()
                 result = self.run_test(index)
                 if name in self.mocks:
                     debug_print('tearing down mocks')
-                    self.mocks[name]['teardown']()
+                    try:
+                        self.mocks[name]['teardown']()
+                    except AssertionError:
+                        debug_print('teardown assert failure')
+                        result = BSTestRunner.FAIL
                 t_stop = time.time()
                 self.sp.logfile = None
                 test_case.elapsed_sec = t_stop - t_start
@@ -167,12 +175,12 @@ class BSTestRunner(object):
         if timeout <= 0:
             return BSTestRunner.TIMEOUT
 
-    def update_env(self):
+    def update_env(self, env_to_set):
-        for env_kv in self.env_vars:
+        for env_kv in env_to_set:
             self.sp.sendline('setenv "{}" "{}"'.format(env_kv[0], env_kv[1]))
             timeout = 10
             while timeout > 0:
-                res = self.sp.expect(['>>>>>bs_test_setenv ok', EOF, TIMEOUT])
+                res = self.sp.expect(['>>>>>bs_test_setenv', EOF, TIMEOUT])
                 if res == 0:
                     break
                 time.sleep(0.1)
@@ -183,6 +191,20 @@ class BSTestRunner(object):
                 return BSTestRunner.TIMEOUT
         return BSTestRunner.SUCCESS
 
+    def request_env(self, key):
+        self.sp.sendline('getenv "{}"'.format(key))
+        timeout = 10
+        while timeout > 0:
+            res = self.sp.expect([r'>>>>>bs_test_getenv value=\"(.+)\"', EOF, TIMEOUT])
+            if res == 0:
+                break
+            time.sleep(0.1)
+            timeout -= 0.1
+        if res != 0:
+            return None
+        return self.sp.match.group(1)
+
+
 ser = None
 
 def spawn_port(port_name, baudrate=115200):

tests/device/libraries/BSTest/src/BSProtocol.h

@@ -48,7 +48,14 @@ void output_menu_end(IO& io)
 template<typename IO>
 void output_setenv_result(IO& io, const char* key, const char* value)
 {
-    io.printf(BS_LINE_PREFIX "setenv ok key='%s' value='%s'\n", key, value);
+    io.printf(BS_LINE_PREFIX "setenv key=\"%s\" value=\"%s\"\n", key, value);
+}
+
+template<typename IO>
+void output_getenv_result(IO& io, const char* key, const char* value)
+{
+    (void) key;
+    io.printf(BS_LINE_PREFIX "getenv value=\"%s\"\n", value);
 }
 
 template<typename IO>
@@ -72,6 +79,15 @@ bool input_handle(IO& io, char* line_buf, size_t line_buf_size, int& test_num)
         test_num = -1;
         return false;   /* we didn't get the test number yet, so return false */
     }
+    if (strcmp(argv[0], "getenv") == 0) {
+        if (argc != 2) {
+            return false;
+        }
+        const char* value = getenv(argv[1]);
+        output_getenv_result(io, argv[1], (value != NULL) ? value : "");
+        return false;
+    }
+    /* not one of the commands, try to parse as test number */
     char* endptr;
     test_num = (int) strtol(argv[0], &endptr, 10);
     if (endptr != argv[0] + strlen(argv[0])) {

tests/device/libraries/BSTest/test/test.cpp

@@ -49,3 +49,12 @@ TEST_CASE("this test also runs successfully", "[bluesmoke]")
 {
 
 }
+
+TEST_CASE("environment variables can be set and read from python", "[bluesmoke]")
+{
+    const char* res = getenv("VAR_FROM_PYTHON");
+    REQUIRE(res != NULL);
+    CHECK(strcmp(res, "42") == 0);
+    setenv("VAR_FROM_TEST", "24", 1);
+}
+

tests/device/libraries/BSTest/test/test.py

@@ -0,0 +1,11 @@
+from mock_decorators import setup, teardown, setenv, request_env
+
+@setup('environment variables can be set and read from python')
+def setup_envtest(e):
+    setenv(e, 'VAR_FROM_PYTHON', '42')
+
+
+@teardown('environment variables can be set and read from python')
+def teardown_envtest(e):
+    env_value = request_env(e, 'VAR_FROM_TEST')
+    assert(env_value == '24')