Update command func to return Error, added tests. (#14)

* test scaffolding

* add github workflow

* match_all not working for now

* more scaffolding

* more tests

* add gitignore

* fix test

* update readme

.github/workflows/test.yml

@@ -0,0 +1,23 @@
+name: Run Tests
+
+on: ["push"]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    environment: basic
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v2
+      - name: Install dependencies
+        run: |
+          curl https://get.modular.com | MODULAR_AUTH=${{ secrets.MODULAR_AUTH }} sh -
+          modular auth ${{ secrets.MODULAR_AUTH }}
+          modular install nightly/mojo
+          pip install pytest
+          pip install git+https://github.com/guidorice/mojo-pytest.git
+      - name: Unit Tests
+        run: |
+          export MODULAR_HOME="/home/runner/.modular"
+          export PATH="/home/runner/.modular/pkg/packages.modular.com_nightly_mojo/bin:$PATH"
+          pytest

.gitignore

@@ -0,0 +1,160 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# poetry
+#   Similar to Pipfile.lock, it is generally recommended to include poetry.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+#   https://python-poetry.org/docs/basic-usage/#commit-your-poetrylock-file-to-version-control
+#poetry.lock
+
+# pdm
+#   Similar to Pipfile.lock, it is generally recommended to include pdm.lock in version control.
+#pdm.lock
+#   pdm stores project-wide configurations in .pdm.toml, but it is recommended to not include it
+#   in version control.
+#   https://pdm.fming.dev/#use-with-ide
+.pdm.toml
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# PyCharm
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+#.idea/

README.md

@@ -19,55 +19,68 @@ from prism import Flag, Command, CommandArc
 from python import Python, PythonObject
 
 
-fn base(command: CommandArc, args: List[String]) raises -> None:
+fn base(command: CommandArc, args: List[String]) -> Error:
     print("This is the base command!")
+    return Error()
 
 
-fn print_information(command: CommandArc, args: List[String]) raises -> None:
+fn print_information(command: CommandArc, args: List[String]) -> Error:
     print("Pass cat or dog as a subcommand, and see what you get!")
+    return Error()
 
 
-fn get_cat_fact(command: CommandArc, args: List[String]) raises -> None:
+fn get_cat_fact(command: CommandArc, args: List[String]) -> Error:
     var flags = command[].get_all_flags()[]
     var lover = flags.get_as_bool("lover")
     if lover and lover.value():
         print("Hello fellow cat lover!")
 
-    var requests = Python.import_module("requests")
-    # URL you want to send a GET request to
-    var url = "https://cat-fact.herokuapp.com/facts/"
+    try:
+        var requests = Python.import_module("requests")
 
-    # Send the GET request
-    var response = requests.get(url)
+        # URL you want to send a GET request to
+        var url = "https://cat-fact.herokuapp.com/facts/"
 
-    # Check if the request was successful (status code 200)
-    if response.status_code == 200:
-        var count = flags.get_as_int("count")
-        if not count:
-            raise Error("Count flag was not found.")
-        var body = response.json()
-        for i in range(count.value()):
-            print(body[i]["text"])
-    else:
-        raise Error("Request failed!")
+        # Send the GET request
+        var response = requests.get(url)
 
+        # Check if the request was successful (status code 200)
+        if response.status_code == 200:
+            var count = flags.get_as_int("count")
+            if not count:
+                return Error("Count flag was not found.")
+            var body = response.json()
+            for i in range(count.value()):
+                print(body[i]["text"])
+        else:
+            return Error("Request failed!")
+    except e:
+        return e
 
-fn get_dog_breeds(command: CommandArc, args: List[String]) raises -> None:
-    var requests = Python.import_module("requests")
-    # URL you want to send a GET request to
-    var url = "https://dog.ceo/api/breeds/list/all"
+    return Error()
 
-    # Send the GET request
-    var response = requests.get(url)
 
-    # Check if the request was successful (status code 200)
-    if response.status_code == 200:
-        print(response.json()["message"])
-    else:
-        raise Error("Request failed!")
+fn get_dog_breeds(command: CommandArc, args: List[String]) -> Error:
+    try:
+        var requests = Python.import_module("requests")
+        # URL you want to send a GET request to
+        var url = "https://dog.ceo/api/breeds/list/all"
 
+        # Send the GET request
+        var response = requests.get(url)
 
-fn init() raises -> None:
+        # Check if the request was successful (status code 200)
+        if response.status_code == 200:
+            print(response.json()["message"])
+        else:
+            return Error("Request failed!")
+    except e:
+        return e
+
+    return Error()
+
+
+fn init() -> None:
     var root_command = Command(name="nested", description="Base command.", run=base)
 
     var get_command = Command(
@@ -96,8 +109,9 @@ fn init() raises -> None:
     root_command.execute()
 
 
-fn main() raises -> None:
+fn main() -> None:
     init()
+
 ```
 
 Start by navigating to the `nested` example directory.
@@ -168,6 +182,8 @@ Usage information will be printed the console by passing the `--help` flag.
 
 - Flags can have values passed by using the `=` operator. Like `--count=5` OR like `--count 5`.
 - Commands can be created via a typical `Command()` constructor to use runtime values, or you can use `Command.new()` method to create a new `Command` using compile time `Parameters` instead (when possible).
+- This library leans towards Errors as values over raising Exceptions.
+- `Optional[Error]` would be much cleaner for Command run functions. For now return `Error()` if there's no `Error` to return.
 
 ## TODO
 
@@ -183,6 +199,8 @@ Usage information will be printed the console by passing the `--help` flag.
 - Map `--help` flag to configurable help function.
 - Add find suggestion logic to `Command` struct.
 - Enable required flags.
+- Replace print usage with writers to enable stdout/stderr/file writing.
+- Split `Run` and `RunE` fields so that the primary run function `Run` can return no errors while `RunE` can return errors.
 
 ### Improvements
 

examples/hello_world/printer.mojo

@@ -2,12 +2,13 @@ from prism import Flag, Command
 from prism.command import CommandArc
 
 
-fn printer(command: CommandArc, args: List[String]) raises -> None:
+fn printer(command: CommandArc, args: List[String]) -> Error:
     if len(args) == 0:
         print("No args provided.")
-        return None
+        return Error()
 
     print(args[0])
+    return Error()
 
 
 fn build_printer_command() -> Command:

examples/hello_world/root.mojo

@@ -11,12 +11,14 @@ from memory._arc import Arc
 
 
 # TODO: Using CommandArc instead of Arc[Command] works. But using Arc[Command] causes a recursive relationship error?
-fn test(command: CommandArc, args: List[String]) raises -> None:
+fn test(command: CommandArc, args: List[String]) -> Error:
     for item in command[].get_all_flags()[].flags:
         print(item[].name, item[].value.value())
 
+    return Error()
 
-fn init() raises -> None:
+
+fn init() -> None:
     var root_command = Command(
         name="tones",
         description="This is a dummy command!",
@@ -38,5 +40,5 @@ fn init() raises -> None:
     root_command.execute()
 
 
-fn main() raises -> None:
+fn main() -> None:
     init()

examples/hello_world/say.mojo

@@ -2,16 +2,19 @@ from prism import Flag, Command
 from prism.command import CommandArc
 
 
-fn say(command: CommandArc, args: List[String]) raises -> None:
+fn say(command: CommandArc, args: List[String]) -> Error:
     print("Shouldn't be here!")
+    return Error()
 
 
-fn say_hello(command: CommandArc, args: List[String]) raises -> None:
+fn say_hello(command: CommandArc, args: List[String]) -> Error:
     print("Hello World!")
+    return Error()
 
 
-fn say_goodbye(command: CommandArc, args: List[String]) raises -> None:
+fn say_goodbye(command: CommandArc, args: List[String]) -> Error:
     print("Goodbye World!")
+    return Error()
 
 
 # for some reason returning the command object without setting it to variable breaks the compiler