Issue 4687 - Add Context Function get_pages_metadata to Test Site

tests/test_site/globals/get_pages_metadata.py

+import re
+from jinja2 import contextfunction
+
+
+@contextfunction
+def get_pages_metadata(context, filters=None):
+    if not isinstance(filters, dict) and filters:
+        raise TypeError('Filters are not a dictionary')
+
+    return_data = []
+    for page_name, _format in context['source'].list_pages():
+        data, filename = context['source'].read_page(page_name, _format)
+        page_data = parse_page_metadata(data, page_name)
+
+        if filter_metadata(filters, page_data) is True:
+            return_data.append(page_data)
+
+    return return_data
+
+
+def parse_page_metadata(data, page):
+    page_metadata = {'page': page}
+    lines = data.splitlines(True)
+    for i, line in enumerate(lines):
+        if not re.search(r'^\s*[\w\-]+\s*=', line):
+            break
+        name, value = line.split('=', 1)
+        value = value.strip()
+        if value.startswith('[') and value.endswith(']'):
+            value = [element.strip() for element in value[1:-1].split(',')]
+        page_metadata[name.strip()] = value
+    return page_metadata
+
+
+def filter_metadata(filters, metadata):
+    if filters is None:
+        return True
+    for filter_name, filter_value in filters.items():
+        if filter_name not in metadata:
+            return False
+        if isinstance(metadata[filter_name], list):
+            if isinstance(filter_value, basestring):
+                filter_value = [filter_value]
+            for option in filter_value:
+                if str(option) not in metadata[filter_name]:
+                    return False
+        elif filter_value != metadata[filter_name]:
+                return False
+    return True