Merge pull request #29 from pmbrull/feature/json

Add JSON rendering

README.md

@@ -19,14 +19,15 @@ Get up and running with
 pip install levy
 ```
 
-So far, it only supports YAML files or reading configurations directly from a `dict`.
+It supports reading both JSON and YAML files, as well as getting configurations
+directly from a `dict`.
 
 The interesting approach here is regarding handling multiple environments. Usually we
 need to pass different parameters depending on where we are (DEV, PROD, and any 
 arbitrary environment name we might use). It is also common to have these specific parameters
 available as env variables, be it our infra or in a CI/CD process.
 
-`levy` adds a `jinja2` layer on top of our YAML files, so that not only we can load
+`levy` adds a `jinja2` layer on top of our config files, so that not only we can load
 env variables on the fly, but helps us leverage templating syntax to keep
 our configurations centralized and DRY.
 
@@ -162,7 +163,7 @@ cfg("not in there")  # AttributeError
 
 ### Environment Variables
 
-With this templating approach on top of YAML, we can not only use default behaviors, but also
+With this templating approach on top of our files, we can not only use default behaviors, but also
 define our own custom functionalities.
 
 The one we have provided by default is reading environment variables at render time:
@@ -178,7 +179,7 @@ we'll get a `MissingEnvException`.
 
 ### Registering new functions
 
-If we need to apply different functions when rendering the YAML, we can register them
+If we need to apply different functions when rendering the files, we can register them
 by name before instantiating the `Config` class.
 
 Let's imagine the following YAML file:
@@ -210,7 +211,7 @@ cfg.foo  # 'X'
 Note how we registered `my_func` with the same name it appeared in the YAML. However,
 the name is completely arbitrary, and we can pass the function `upper` with the name `bar`.
 
-With this approach one can add even further dynamism to the YAML config files.
+With this approach one can add even further dynamism to both YAML and JSON config files.
 
 To peek into the registry state, we can run:
 
@@ -228,7 +229,7 @@ Which in the example will show us
 
 ## Schema Validation
 
-At some point it might be interesting to make sure that the YAML we are reading follows
+At some point it might be interesting to make sure that the config we are reading follows
 some standards. That is why we have introduced the ability to pass a schema our file
 needs to follow.
 
@@ -266,7 +267,7 @@ assert cfg.age is None
 assert cfg.friends.lima.fur == "soft"
 ```
 
-Note how this adds even another layer of flexibility, as after reading the YAML we will
+Note how this adds even another layer of flexibility, as after reading the file we will
 have all the data we might require available to use.
 
 ## Contributing

docs/functions.md

@@ -17,7 +17,7 @@ We can then access these values as usual.
 
 ## Registering new functions
 
-If we need to apply different functions when rendering the YAML, we can register them
+If we need to apply different functions when rendering the files, we can register them
 by name before instantiating the `Config` class.
 
 Let's imagine the following YAML file:
@@ -60,7 +60,7 @@ $ cfg.foo
 Note how we registered `my_func` with the same name it appeared in the YAML. However,
 the name is completely arbitrary, and we can pass the function `upper` with the name `bar`.
 
-With this approach one can add even further dynamism to the YAML config files.
+With this approach one can add even further dynamism to our config files.
 
 ## Registry
 

docs/index.md

@@ -1,5 +1,5 @@
 <p align="center">
-    <em>Supercharge YAML configs with Jinja templates, typing and custom functions.</em>
+    <em>Supercharge configs with Jinja templates, typing and custom functions.</em>
 </p>
 <p align="center">
 <a href="https://pypi.org/project/levy/" target="_blank">
@@ -46,9 +46,10 @@ This will also bring to your environment `PyYAML`, `Jinja2` and `pydantic`.
 
 ## Quickstart
 
-This project is a lightweight take on configuration parsing with a twist.  So far, it only supports YAML files or reading configurations directly from a `dict`.
+This project is a lightweight take on configuration parsing with a twist. It supports reading both JSON and YAML files, as well as getting configurations
+directly from a `dict`.
 
-`levy` adds a `jinja2` layer on top our YAML files, which allows us to run any Jinja templating syntax on them. Later on, we will also see how to register our own custom functions.
+`levy` adds a `jinja2` layer on top our config files, which allows us to run any Jinja templating syntax on them. Later on, we will also see how to register our own custom functions.
 
 Let's suppose we have the following configuration:
 

docs/json.md

@@ -0,0 +1,45 @@
+## Rendering JSON Files
+
+`levy` supports JSON file as well as YAML. All the features remain the same, however,
+we need to make sure that the JSON file we write is a correctly formatted JSON
+after the render phase, which might be a bit tricky at times.
+
+> OBS: Note that the added difficulty is only for Jinja templating, as we need to
+  take care about putting all the quotes and commas.
+
+Let's revisit the first example we saw, and how it would look like as a JSON file:
+
+```json
+{
+  "title": "Lévy the cat",
+  "colors": ["black", "white"],
+  "hobby": {
+    "eating": {
+      "what": "anything"
+    }
+  },
+  "friends": [
+    {% set friends = [ "cartman", "lima" ] %}
+    {% for friend in friends %}
+      {
+        "name": "${ friend }",
+        "type": "cat"
+      }
+        {% if loop.index0 < friends|length - 1%}
+        ,
+        {% endif %}
+    {% endfor %}
+    ]
+}
+```
+
+As you can see, most of it is the same. However, in the `friends` list, we need
+to add specific logic to add commas `,` if we have not reached the end of the loop.
+
+Afterwards, the API remains:
+
+```python
+from levy.config import Config
+
+cfg = Config.read_file("test.json")
+```

docs/schema.md

@@ -50,7 +50,7 @@ class Kitten(BaseModel):
 cfg = Config.read_file("<file>", datatype=Kitten)
 ```
 
-Note how this adds even another layer of flexibility, as after reading the YAML we will
+Note how this adds even another layer of flexibility, as after reading the config we will
 have all the data we might require available to use.
 
 

levy/__init__.py

@@ -1,3 +1,3 @@
 """Dynamic python configuration parser"""
 
-__version__ = "0.5.1"
+__version__ = "0.6.1"

levy/config.py

@@ -1,8 +1,10 @@
 """
 Config parser definition
 """
+import json
 import logging
 from collections import namedtuple
+from pathlib import Path
 from typing import Any, Dict, Generic, List, Optional, TypeVar
 
 import yaml
@@ -54,11 +56,25 @@ def read_file(
         :return:
         """
 
-        with open(file, "r") as yml_file:
-            rendered = render_str(yml_file.read())
-            cfg = cls.read_dict(
-                yaml.safe_load(rendered), name=name, list_id=list_id, datatype=datatype
-            )
+        # Check file extension
+        ext = Path(file).suffix
+
+        if ext == ".yaml":
+            with open(file, "r") as yml_file:
+                rendered = render_str(yml_file.read())
+                cfg = cls.read_dict(
+                    yaml.safe_load(rendered),
+                    name=name,
+                    list_id=list_id,
+                    datatype=datatype,
+                )
+
+        if ext == ".json":
+            with open(file, "r") as json_file:
+                rendered = render_str(json_file.read())
+                cfg = cls.read_dict(
+                    json.loads(rendered), name=name, list_id=list_id, datatype=datatype
+                )
 
         cfg._file = file  # pylint: disable=attribute-defined-outside-init
         return cfg

mkdocs.yml

@@ -34,6 +34,7 @@ nav:
     - Nested Config Lists: lists.md
     - Render Custom Functions: functions.md
     - Schema Validation: schema.md
+    - JSON Files: json.md
     - Contributing: contributing.md
     - References: references.md
 

tests/resources/test.json

@@ -0,0 +1,21 @@
+{
+  "title": "Lévy the cat",
+  "colors": ["black", "white"],
+  "hobby": {
+    "eating": {
+      "what": "anything"
+    }
+  },
+  "friends": [
+    {% set friends = [ "cartman", "lima" ] %}
+    {% for friend in friends %}
+      {
+        "name": "${ friend }",
+        "type": "cat"
+      }
+        {% if loop.index0 < friends|length - 1%}
+        ,
+        {% endif %}
+    {% endfor %}
+    ]
+}

tests/test_config.py

@@ -1,13 +1,13 @@
 import os
-import pytest
 from typing import Dict, List, Optional
 from unittest import mock
 
+import pytest
 from pydantic import BaseModel, ValidationError
 
 from levy.config import Config
-from levy.renderer import render_reg
 from levy.exceptions import ListParseException
+from levy.renderer import render_reg
 
 
 class TestConfig:
@@ -17,6 +17,7 @@ def setup(self):
         self.resources = os.path.join(self.dir, "resources")
 
         self.file = os.path.join(self.resources, "test.yaml")
+        self.json_file = os.path.join(self.resources, "test.json")
         self.cfg = Config.read_file(file=self.file)
 
     def test_name(self):
@@ -136,3 +137,12 @@ class Kitten(BaseModel):
         with pytest.raises(ValidationError):
             file = os.path.join(self.resources, "test_ko.yaml")
             Config.read_file(file, datatype=Kitten)
+
+    def test_json(self):
+        """
+        Validate JSON file read
+        """
+        cfg = Config.read_file(self.json_file)
+        cfg_yaml = Config.read_file(self.file)
+
+        assert cfg._vars == cfg_yaml._vars