Create replace_tmpl filter for Jinja2 (#33)

src/wxflow/jinja.py

@@ -1,5 +1,6 @@
 import os
 import sys
+from functools import reduce
 from pathlib import Path
 from typing import Dict, List, Union
 
@@ -110,6 +111,7 @@ def get_set_env(self, loader: jinja2.BaseLoader, filters: Dict[str, callable] =
         getenv: read variable from environment if defined, else UNDEFINED
         to_timedelta: convert a string to a timedelta object
         add_to_datetime: add time to a datetime, return new datetime object
+        replace_tmpl: replace substrings of an input string with replacements specified by an input dictionary
 
         The Expression Statement extension "jinja2.ext.do", which enables
             {% do ... %} statements.  These are useful for appending to lists.
@@ -146,6 +148,7 @@ def get_set_env(self, loader: jinja2.BaseLoader, filters: Dict[str, callable] =
                 if not (isinstance(dt, SilentUndefined) or isinstance(delta, SilentUndefined))
                 else dt if isinstance(dt, SilentUndefined) else delta)
         env.filters["to_timedelta"] = lambda delta_str: to_timedelta(delta_str) if not isinstance(delta_str, SilentUndefined) else delta_str
+        env.filters["replace_tmpl"] = lambda string, tmpl_dict: reduce(lambda ss, kk: ss.replace(kk, tmpl_dict[kk]), tmpl_dict, string)
 
         # Add any additional filters
         if filters is not None:

src/wxflow/task.py

@@ -41,7 +41,7 @@ def __init__(self, config: Dict, *args, **kwargs):
         # Create task_config with everything that is inside _config and whatever the user chooses to
         # extend it with when initializing a child subclass of Task. Only task_config should be referenced
         # in any application, not _config.
-        self.task_config = self._config.copy()
+        self.task_config = self._config.deepcopy()
 
         # Any other composite runtime variables that may be needed for the duration of the task
         # can be constructed here

tests/test_jinja.py

@@ -1,5 +1,6 @@
 from datetime import datetime
 
+import jinja2
 import pytest
 
 from wxflow import Jinja, to_isotime
@@ -29,6 +30,12 @@ def test_render_stream():
     j = Jinja(j2tmpl, data, allow_missing=False)
     assert j.render == f"Hello Jane! How are you? It is: {to_isotime(current_date)}"
 
+    tmpl_dict = {"{{ name }}": "Jane", "{{ greeting }}": "How are you?", "{{ current_date | to_isotime }}": to_isotime(current_date)}
+    j = Jinja(j2tmpl, data, allow_missing=False)
+    loader = jinja2.BaseLoader()
+    env = j.get_set_env(loader)
+    assert env.filters['replace_tmpl'](j2tmpl, tmpl_dict) == f"Hello Jane! How are you? It is: {to_isotime(current_date)}"
+
 
 def test_render_file(tmp_path, create_template):
 
@@ -41,6 +48,12 @@ def test_render_file(tmp_path, create_template):
     j = Jinja(str(file_path), data, allow_missing=False)
     assert j.render == f"Hello Jane! How are you? It is: {to_isotime(current_date)}"
 
+    tmpl_dict = {"{{ name }}": "Jane", "{{ greeting }}": "How are you?", "{{ current_date | to_isotime }}": to_isotime(current_date)}
+    j = Jinja(str(file_path), data, allow_missing=False)
+    loader = jinja2.BaseLoader()
+    env = j.get_set_env(loader)
+    assert env.filters['replace_tmpl'](j2tmpl, tmpl_dict) == f"Hello Jane! How are you? It is: {to_isotime(current_date)}"
+
 
 def test_include(tmp_path, create_template):