Fix result_dep, use result **after** its execution

CHANGES

@@ -19,6 +19,7 @@ Changes
  - Fix #267: `doit list` now has a `--sort` parameter to determine the order in which the tasks are listed.
  - Make it possible to use a custom encoder when using config_changed with a dict.
  - Add configuration `DOIT_CONFIG` `action_string_formatting` to control command action formatter.
+ - Fix `result_dep`, use result **after** its execution
 
 
 0.31.1 (*2018-03-18*)

doit/task.py

@@ -6,7 +6,6 @@
 import sys
 import inspect
 from collections import OrderedDict
-from functools import partial
 from pathlib import PurePath
 
 from .cmdparse import CmdOption, TaskParse
@@ -595,9 +594,6 @@ def clean_targets(task, dryrun):
                 os.rmdir(dir_)
 
 
-def _return_param(val):
-    '''just return passed parameter - make a callable from any value'''
-    return val
 
 # uptodate
 class result_dep(UptodateCalculator):
@@ -635,15 +631,23 @@ def _result_group(self, dep_task):
                 sub_tasks[sub] = self.get_val(sub, 'result:')
         return sub_tasks
 
-    def __call__(self, task, values):
-        """return True if result is the same as last run"""
-        dep_task = self.tasks_dict[self.dep_name]
+    def _get_dep_result(self, dep_task):
         if not dep_task.has_subtask:
             dep_result = self._result_single()
         else:
             dep_result = self._result_group(dep_task)
-        func = partial(_return_param, {self.result_name: dep_result})
-        task.value_savers.append(func)
+        return dep_result
+
+
+    def __call__(self, task, values):
+        """return True if result is the same as last run"""
+        dep_task = self.tasks_dict[self.dep_name]
+        dep_result = self._get_dep_result(dep_task)
+
+        def result_saver():
+            # get latest value after execution of dependent task
+            return {self.result_name: self._get_dep_result(dep_task)}
+        task.value_savers.append(result_saver)
 
         last_success = values.get(self.result_name)
         if last_success is None:

tests/test_task.py

@@ -611,9 +611,6 @@ def test_single(self, dep_manager):
         # t2 result changed
         tasks['t2'].result = '222'
         dep_manager.save_success(tasks['t2'])
-
-        tasks['t1'].save_extra_values()
-        dep_manager.save_success(tasks['t1'])
         assert 'run' == dep_manager.get_status(tasks['t1'], tasks).status
 
         tasks['t1'].save_extra_values()
@@ -645,9 +642,6 @@ def test_group(self, dep_manager):
         # t2 result changed
         tasks['t2:a'].result = '222'
         dep_manager.save_success(tasks['t2:a'])
-
-        tasks['t1'].save_extra_values()
-        dep_manager.save_success(tasks['t1'])
         assert 'run' == dep_manager.get_status(tasks['t1'], tasks).status
 
         tasks['t1'].save_extra_values()