Fix spec command for complex data types (#549)

* Fix spec command for complex data types

* PR feedback: switch to using Flask's json module

---------

Co-authored-by: Tayler Sokalski <tsokalski@users.noreply.github.com>

CHANGES.md

@@ -3,9 +3,11 @@
 Released: -
 - Reuse the File, Config field, and file-related validators from flask-marshmallow ([issue #540][issue_540]).
 - Add support for a `--quiet` option to the `flask spec` command ([issue #548][issue_548]).
+- Fix the `flask spec` command for validators operating on complex data types ([issue #547][issue_547]).
 
 [issue_540]: https://github.com/apiflask/apiflask/issues/540
 [issue_548]: https://github.com/apiflask/apiflask/issues/548
+[issue_547]: https://github.com/apiflask/apiflask/issues/547
 
 
 ## Version 2.1.0

src/apiflask/app.py

@@ -1,5 +1,4 @@
 import inspect
-import json
 import re
 import typing as t
 import warnings
@@ -11,6 +10,7 @@
 from flask import Blueprint
 from flask import Flask
 from flask import has_request_context
+from flask import json
 from flask import jsonify
 from flask import render_template_string
 from flask import request

src/apiflask/commands.py

@@ -1,7 +1,6 @@
-import json
-
 import click
 from flask import current_app
+from flask import json
 from flask.cli import with_appcontext
 
 

tests/schemas.py

@@ -1,6 +1,8 @@
 from marshmallow import EXCLUDE
+from marshmallow.validate import Range
 
 from apiflask import Schema
+from apiflask.fields import Decimal
 from apiflask.fields import File
 from apiflask.fields import Integer
 from apiflask.fields import List
@@ -29,6 +31,10 @@ class Baz(Schema):
     name = String()
 
 
+class Qux(Schema):
+    number = Decimal(validate=Range(min=0))
+
+
 class Query(Schema):
     class Meta:
         unknown = EXCLUDE

tests/test_commands.py

@@ -3,6 +3,7 @@
 import pytest
 
 from .schemas import Foo
+from .schemas import Qux
 from apiflask.commands import spec_command
 
 
@@ -76,3 +77,13 @@ def test_flask_spec_indent(cli_runner, indent, tmp_path):
 def test_flask_spec_quiet(app, cli_runner):
     result = cli_runner.invoke(spec_command, ['--quiet'])
     assert result.output == ''
+
+
+def test_flask_spec_decimal_field(app, cli_runner):
+    @app.get('/qux')
+    @app.output(Qux)
+    def qux():
+        pass
+
+    result = cli_runner.invoke(spec_command)
+    assert 'openapi' in result.output