add script globals to common to match backend (#3090)

Author: burnettk

spiff-arena-common/pyproject.toml

@@ -1,13 +1,14 @@
 [project]
 name = "spiff-arena-common"
-version = "0.1.49"
+version = "0.1.50"
 description = "Shared Python utilities for Spiff Arena frontend and backend components."
 readme = "README.md"
 requires-python = ">=3.10"
 
 dependencies = [
     "Jinja2==3.1.6",
     "jsonschema==4.26.0",
+    "pytz>=2025.2",
     "SpiffWorkflow==3.2.1a1788363675",
 ]
 

spiff-arena-common/src/spiff_arena_common/runner.py

@@ -1,14 +1,20 @@
 import base64
 import calendar
 import datetime
+import decimal
 import gzip
+import hashlib
 import json
 import logging
+import random
+import re
 import time
 import uuid
 from types import ModuleType
+from urllib.parse import unquote
 
 import jsonschema
+import pytz
 
 
 # This encoder/decoder replicates the type conversion behavior of
@@ -259,16 +265,32 @@ class CustomParser(SpiffBpmnParser):
 del SPIFF_CONFIG[SendTask]
 del SPIFF_CONFIG[StartEvent]
 
+def _markdown_file_download_link(file_reference):
+    # Arena passes "data:<mimetype>;name=<name>;base64,spifffiledatadigest+<sha256>";
+    # Ed's forms keep the file contents inline instead of a digest.
+    metadata, payload = file_reference.rsplit(";base64,", 1)
+    match = re.fullmatch(r"spifffiledatadigest\+([0-9a-f]{64})", payload)
+    digest = match.group(1) if match else hashlib.sha256(base64.b64decode(payload)).hexdigest()
+    filename = unquote(metadata.split(";name=", 1)[1]) if ";name=" in metadata else digest
+    label = re.sub(r"([\\\\`*\[\]_<>&])", r"\\\1", filename)
+    return f"[{label}](http://local.spiff/process-data-file-download/local/0/{digest})"
+
+
 class CustomEnvironment(TaskDataEnvironment):
     def __init__(self):
         # TODO: would be nice to get these from the client so we don't have to code change for globals
         super().__init__(environment_globals={
             "calendar": calendar,
             "datetime": datetime.datetime,
+            "decimal": decimal,
             "json": json,
             "jsonschema": jsonschema,
+            "pytz": pytz,
+            "random": random,
+            "re": re,
             "time": time,
             "timedelta": datetime.timedelta,
+            "uuid": uuid,
         })
 
     def _build_external_context(self, context, external_context=None):
@@ -301,6 +323,8 @@ def _build_external_context(self, context, external_context=None):
         external_context["get_process_initiator_user"] = lambda: {
             key: value for key, value in process_initiator_user.items()
         }
+        external_context["markdown_file_download_link"] = _markdown_file_download_link
+        external_context["get_markdown_file_download_link"] = _markdown_file_download_link
         external_context["get_group_members"] = lambda group_name: [
             "group_member_1@example.com",
             "group_member_2@example.com",

spiff-arena-common/tests/spiff_arena_common/test_runner.py

@@ -1,3 +1,4 @@
+import hashlib
 import json
 from types import SimpleNamespace
 
@@ -1074,3 +1075,52 @@ def connector_404(*_args, **_kwargs):
     assert result["status"] == "ok"
     assert result["completed"] is True
     assert result["result"]["route"] == "handled"
+
+
+def test_custom_environment_provides_arena_script_modules():
+    context = {}
+
+    result = runner.CustomEnvironment().execute(
+        'tz = pytz.timezone("US/Central").zone\n'
+        'amount = str(decimal.Decimal("1.10") + decimal.Decimal("2.20"))\n'
+        'matched = re.match(r"\\d+", "42abc").group(0)\n'
+        'picked = random.choice(["only"])\n'
+        'is_uuid = isinstance(uuid.uuid4(), uuid.UUID)',
+        context,
+    )
+
+    assert result is True
+    assert context["tz"] == "US/Central"
+    assert context["amount"] == "3.30"
+    assert context["matched"] == "42"
+    assert context["picked"] == "only"
+    assert context["is_uuid"] is True
+
+
+def test_custom_environment_markdown_file_download_link_handles_arena_digest_references():
+    digest = "7a2051ffefd1eaf475dbef9fda019cb3d4a10eb8aea4c2c2a84a50a797a541bf"
+    context = {"file": f"data:text/plain;name=my%20report_v1.txt;base64,spifffiledatadigest+{digest}"}
+
+    result = runner.CustomEnvironment().execute(
+        "link = markdown_file_download_link(file)\n"
+        "legacy_link = get_markdown_file_download_link(file)",
+        context,
+    )
+
+    assert result is True
+    expected = f"[my report\\_v1.txt](http://local.spiff/process-data-file-download/local/0/{digest})"
+    assert context["link"] == expected
+    assert context["legacy_link"] == expected
+
+
+def test_custom_environment_markdown_file_download_link_handles_inline_file_data():
+    context = {"files": ["data:text/plain;name=notes.txt;base64,ZHVtbXk="]}
+
+    result = runner.CustomEnvironment().execute(
+        "links = [markdown_file_download_link(f) for f in files]",
+        context,
+    )
+
+    assert result is True
+    digest = hashlib.sha256(b"dummy").hexdigest()
+    assert context["links"] == [f"[notes.txt](http://local.spiff/process-data-file-download/local/0/{digest})"]