added requirement tests

functionality/requirements.py

@@ -5,6 +5,9 @@ requirements, and assessed by handlers and conductors.
 Author(s): David Marchant
 """
 
+from importlib.util import find_spec
+from os.path import basename
+from sys import version_info, prefix, base_prefix
 from typing import Any, Dict, List, Tuple, Union
 
 from core.correctness.validation import check_type
@@ -14,7 +17,6 @@ REQ_PYTHON_MODULES = "modules"
 REQ_PYTHON_VERSION = "version"
 REQ_PYTHON_ENVIRONMENT = "environment"
 
-
 def create_requirement_dict(key:str, entires:Dict[str,Any]
         )->Tuple[str,Dict[str,Any]]:
     return key, entires
@@ -41,3 +43,65 @@ def create_python_requirements(modules:Union[str,List[str]]="",
         python_reqs[REQ_PYTHON_ENVIRONMENT] = environment
 
     return create_requirement_dict(REQUIREMENT_PYTHON, python_reqs)
+
+def check_requirements(requirements:Dict[str,Any])->bool:
+    check_type(requirements, dict, hint="check_requirements.requirements")
+    result = True
+    reason = ""
+    for key, value in SUPPORTERD_REQS.items():
+        if key in requirements:
+            status, msg = value(requirements[key])
+            if not status:
+                result = False
+                reason = msg
+    return result, reason
+
+# TODO integrate me into conductors
+def check_python_requirements(reqs:Dict[str,Any])->bool:
+    check_type(reqs, dict, 
+        hint=f"check_requirements.reqs[{REQUIREMENT_PYTHON}]")
+
+    if REQ_PYTHON_ENVIRONMENT in reqs:
+        if base_prefix == prefix:
+            return False, "" 
+        
+        if basename(prefix) != reqs[REQ_PYTHON_ENVIRONMENT]:
+            return False, ""
+        
+    # TODO expand these so you can specify versions
+    if REQ_PYTHON_MODULES in reqs:
+        for module in reqs[REQ_PYTHON_MODULES]:
+            found_spec = find_spec(module)
+            if found_spec is None:
+                return False, f"Could not find module '{module}'."
+
+    if REQ_PYTHON_VERSION in reqs:
+        major, minor, micro = parse_versions(reqs[REQ_PYTHON_VERSION]) 
+
+        msg = f"Avaiable Python version number '{version_info[0]}." \
+            f"{version_info[1]}.{version_info[2]}' does not meet requested " \
+            f"{reqs[REQ_PYTHON_VERSION]}."
+        if major and int(version_info[0]) < major:
+            return False, msg
+        if minor and int(version_info[0]) <= major \
+                and int(version_info[1]) < minor:
+            return False, msg
+        if micro and int(version_info[0]) <= major \
+                and int(version_info[1]) <= minor \
+                and int(version_info[2]) < micro:
+            return False, msg
+
+    return True, ""
+
+def parse_versions(version:str)->None:
+    parts = version.split('.')
+    if len(parts) == 1:
+        return int(parts[0]), None, None
+    elif len(parts) == 2:
+        return int(parts[0]), int(parts[1]), None
+    else:
+        return int(parts[0]), int(parts[1]), int(parts[2])
+
+SUPPORTERD_REQS = {
+    REQUIREMENT_PYTHON: check_python_requirements,
+}