Feature: add @jinja and @format casting

.github/workflows/update_contributors.yml

@@ -19,7 +19,7 @@ jobs:
           commit-message: Update Contributors
           title: "[automated] Update Contributors File"
           token: ${{ secrets.GITHUB_TOKEN }}
-          
+
 #       - name: Update resources
 #         uses: test-room-7/action-update-file@v1
 #         with:

dynaconf/utils/parse_conf.py

@@ -166,9 +166,12 @@ class Lazy:
 
     _dynaconf_lazy_format = True
 
-    def __init__(self, value=empty, formatter=Formatters.python_formatter):
+    def __init__(
+        self, value=empty, formatter=Formatters.python_formatter, casting=None
+    ):
         self.value = value
         self.formatter = formatter
+        self.casting = casting
 
     @property
     def context(self):
@@ -179,7 +182,10 @@ def __call__(self, settings, validator_object=None):
         """LazyValue triggers format lazily."""
         self.settings = settings
         self.context["_validator_object"] = validator_object
-        return self.formatter(self.value, **self.context)
+        result = self.formatter(self.value, **self.context)
+        if self.casting is not None:
+            result = self.casting(result)
+        return result
 
     def __str__(self):
         """Gives string representation for the object."""
@@ -193,6 +199,11 @@ def _dynaconf_encode(self):
         """Encodes this object values to be serializable to json"""
         return f"@{self.formatter} {self.value}"
 
+    def set_casting(self, casting):
+        """Set the casting and return the instance."""
+        self.casting = casting
+        return self
+
 
 def try_to_encode(value, callback=str):
     """Tries to encode a value by verifying existence of `_dynaconf_encode`"""
@@ -215,11 +226,25 @@ def evaluate(settings, *args, **kwargs):
 
 
 converters = {
-    "@str": str,
-    "@int": int,
-    "@float": float,
-    "@bool": lambda value: str(value).lower() in true_values,
-    "@json": json.loads,
+    "@str": lambda value: value.set_casting(str)
+    if isinstance(value, Lazy)
+    else str(value),
+    "@int": lambda value: value.set_casting(int)
+    if isinstance(value, Lazy)
+    else int(value),
+    "@float": lambda value: value.set_casting(float)
+    if isinstance(value, Lazy)
+    else float(value),
+    "@bool": lambda value: value.set_casting(
+        lambda x: str(x).lower() in true_values
+    )
+    if isinstance(value, Lazy)
+    else str(value).lower() in true_values,
+    "@json": lambda value: value.set_casting(
+        lambda x: json.loads(x.replace("'", '"'))
+    )
+    if isinstance(value, Lazy)
+    else json.loads(value),
     "@format": lambda value: Lazy(value),
     "@jinja": lambda value: Lazy(value, formatter=Formatters.jinja_formatter),
     # Meta Values to trigger pre assignment actions
@@ -279,10 +304,13 @@ def _parse_conf_data(data, tomlfy=False, box_settings=None):
         and isinstance(data, str)
         and data.startswith(tuple(converters.keys()))
     ):
-        parts = data.partition(" ")
-        converter_key = parts[0]
-        value = parts[-1]
-        value = get_converter(converter_key, value, box_settings)
+        # Parse the converters iteratively
+        num_converters = data.count("@")
+        parts = data.split(" ", num_converters)
+        converter_key_list = parts[:num_converters]
+        value = parts[-1] if len(parts) > 1 else ""  # for @del
+        for converter_key in converter_key_list[::-1]:
+            value = get_converter(converter_key, value, box_settings)
     else:
         value = parse_with_toml(data) if tomlfy else data
 

tests/test_utils.py

@@ -105,6 +105,70 @@ def test_find_file(tmpdir):
     ) == os.path.join(str(tmpdir), ".env")
 
 
+def test_casting_str(settings):
+    res = parse_conf_data("@str 7")
+    assert isinstance(res, str) and res == "7"
+
+    settings.set("value", 7)
+    res = parse_conf_data("@str @jinja {{ this.value }}")(settings)
+    assert isinstance(res, str) and res == "7"
+
+    res = parse_conf_data("@str @format {this.value}")(settings)
+    assert isinstance(res, str) and res == "7"
+
+
+def test_casting_int(settings):
+    res = parse_conf_data("@int 2")
+    assert isinstance(res, int) and res == 2
+
+    settings.set("value", 2)
+    res = parse_conf_data("@int @jinja {{ this.value }}")(settings)
+    assert isinstance(res, int) and res == 2
+
+    res = parse_conf_data("@int @format {this.value}")(settings)
+    assert isinstance(res, int) and res == 2
+
+
+def test_casting_float(settings):
+    res = parse_conf_data("@float 0.3")
+    assert isinstance(res, float) and abs(res - 0.3) < 1e-6
+
+    settings.set("value", 0.3)
+    res = parse_conf_data("@float @jinja {{ this.value }}")(settings)
+    assert isinstance(res, float) and abs(res - 0.3) < 1e-6
+
+    res = parse_conf_data("@float @format {this.value}")(settings)
+    assert isinstance(res, float) and abs(res - 0.3) < 1e-6
+
+
+def test_casting_bool(settings):
+    res = parse_conf_data("@bool true")
+    assert isinstance(res, bool) and res is True
+
+    settings.set("value", "true")
+    res = parse_conf_data("@bool @jinja {{ this.value }}")(settings)
+    assert isinstance(res, bool) and res is True
+
+    settings.set("value", "false")
+    res = parse_conf_data("@bool @format {this.value}")(settings)
+    assert isinstance(res, bool) and res is False
+
+
+def test_casting_json(settings):
+    res = parse_conf_data("@json {'FOO': 'bar'}")
+    assert isinstance(res, dict)
+    assert "FOO" in res and "bar" in res.values()
+
+    settings.set("value", "{'FOO': 'bar'}")
+    res = parse_conf_data("@json @jinja {{ this.value }}")(settings)
+    assert isinstance(res, dict)
+    assert "FOO" in res and "bar" in res.values()
+
+    res = parse_conf_data("@json @format {this.value}")(settings)
+    assert isinstance(res, dict)
+    assert "FOO" in res and "bar" in res.values()
+
+
 def test_disable_cast(monkeypatch):
     # this casts for int
     assert parse_conf_data("@int 42", box_settings={}) == 42