Render patternProperties (#419)

* Render patterProperties

* Use exception class rather than generic Exception

* fixed tests

* Addressing some PR comments

* Consider that objects can have no properties

* Adding missed schema for no prop tests

src/rpdk/core/project.py

@@ -76,6 +76,18 @@
 }
 
 
+MARKDOWN_RESERVED_CHARACTERS = frozenset({"^", "*", "+", ".", "(", "[", "{", "#"})
+
+
+def escape_markdown(string):
+    """Escapes the reserved Markdown characters."""
+    if not string:
+        return string
+    if string[0] in MARKDOWN_RESERVED_CHARACTERS:
+        return "\\{}".format(string)
+    return string
+
+
 class Project:  # pylint: disable=too-many-instance-attributes
     def __init__(self, overwrite_enabled=False, root=None):
         self.overwrite_enabled = overwrite_enabled
@@ -98,6 +110,8 @@ def __init__(self, overwrite_enabled=False, root=None):
             autoescape=select_autoescape(["html", "htm", "xml", "md"]),
         )
 
+        self.env.filters["escape_markdown"] = escape_markdown
+
         LOG.debug("Root directory: %s", self.root)
 
     @property
@@ -399,7 +413,9 @@ def _get_property_description(prop):
             for prop in docs_schema.get("readOnlyProperties", [])
         ]
 
-    def _set_docs_properties(self, propname, prop, proppath):
+    def _set_docs_properties(
+        self, propname, prop, proppath
+    ):  # pylint: disable=too-many-locals
         if "$ref" in prop:
             prop = RefResolver.from_schema(self.schema).resolve(prop["$ref"])[1]
 
@@ -432,9 +448,13 @@ def _set_docs_properties(self, propname, prop, proppath):
             template = self.env.get_template("docs-subproperty.md")
             docs_path = self.root / "docs"
 
+            object_properties = (
+                prop.get("properties") or prop.get("patternProperties") or {}
+            )
+
             prop["properties"] = {
                 name: self._set_docs_properties(name, value, proppath + (name,))
-                for name, value in prop["properties"].items()
+                for name, value in object_properties.items()
             }
 
             subproperty_name = " ".join(proppath)

src/rpdk/core/templates/docs-subproperty.md

@@ -41,7 +41,7 @@ To declare this entity in your AWS CloudFormation template, use the following sy
 
 {% for propname, prop in schema.properties.items() %}
 {% if not prop.readonly %}
-#### {{ propname }}
+#### {{ propname | escape_markdown }}
 {% if prop.description %}
 
 {{ prop.description }}

tests/data/schema/valid/valid_no_properties.json

@@ -0,0 +1,17 @@
+{
+    "typeName": "AWS::Valid::TypeName",
+    "description": "a test schema",
+    "properties": {
+        "obj2": {
+            "type": "object",
+            "description": "obj with no props"
+        }
+    },
+    "primaryIdentifier": [
+        "/properties/enum1"
+    ],
+    "readOnlyProperties": [
+        "/properties/str3"
+    ],
+    "additionalProperties": false
+}

tests/data/schema/valid/valid_pattern_properties.json

@@ -0,0 +1,81 @@
+{
+    "typeName": "AWS::Valid::TypeName",
+    "description": "a test schema",
+    "definitions": {
+        "obj1def": {
+            "type": "object",
+            "additionalProperties": false,
+            "properties": {
+                "str1": {
+                    "type": "string",
+                    "minLength": 2
+                }
+            }
+        },
+        "obj2def": {
+            "type": "object",
+            "additionalProperties": false,
+            "patternProperties": {
+                ".*": {
+                    "type": "string"
+                }
+            }
+        }
+    },
+    "properties": {
+        "enum1": {
+            "type": "string",
+            "enum": [
+                "test",
+                "test2"
+            ]
+        },
+        "str2": {
+            "type": "string",
+            "description": "some description"
+        },
+        "obj1": {
+            "type": "object",
+            "description": "",
+            "$ref": "#/definitions/obj1def"
+        },
+        "obj2": {
+            "type": "object",
+            "description": "",
+            "$ref": "#/definitions/obj2def"
+        },
+        "str3": {
+            "type": "string",
+            "description": ""
+        },
+        "arr1": {
+            "type": "array",
+            "description": "",
+            "items": {
+                "$ref": "#/definitions/obj2def"
+            }
+        }
+    },
+    "primaryIdentifier": [
+        "/properties/enum1"
+    ],
+    "readOnlyProperties": [
+        "/properties/str3"
+    ],
+    "additionalIdentifiers": [
+        [
+            "/properties/enum1",
+            "/properties/str2"
+        ],
+        [
+            "/properties/obj1/obj2/str1"
+        ],
+        [
+            "/properties/str2"
+        ]
+    ],
+    "createOnlyProperties": [
+        "/properties/str2"
+    ],
+    "additionalProperties": false
+}

tests/test_project.py

@@ -28,6 +28,7 @@
     SCHEMA_UPLOAD_FILENAME,
     SETTINGS_FILENAME,
     Project,
+    escape_markdown,
 )
 from rpdk.core.test import empty_override
 from rpdk.core.upload import Uploader
@@ -58,6 +59,25 @@
 }
 
 
+@pytest.mark.parametrize(
+    "string", ["^[a-z]$", "([a-z])", ".*", "*."],
+)
+def test_escape_markdown_with_regex_names(string):
+    assert escape_markdown(string).startswith("\\")
+
+
+def test_escape_markdown_with_empty_string():
+    assert escape_markdown("") == ""
+    assert escape_markdown(None) is None
+
+
+@pytest.mark.parametrize(
+    "string", ["Hello", "SomeProperty"],
+)
+def test_escape_markdown(string):
+    assert escape_markdown(string) == string
+
+
 @pytest.fixture
 def project(tmpdir):
     unique_dir = "".join(random.choices(string.ascii_uppercase, k=12))
@@ -185,6 +205,14 @@ def test_generate_no_handlers(project):
             "data/schema/valid/valid_type_complex.json",
             "generate_with_docs_type_complex",
         ),
+        (
+            "data/schema/valid/valid_pattern_properties.json",
+            "generate_with_docs_pattern_properties",
+        ),
+        (
+            "data/schema/valid/valid_no_properties.json",
+            "generate_with_docs_no_properties",
+        ),
         (
             "data/schema/valid/valid_nested_property_object.json",
             "generate_with_docs_nested_object",