Re #265 - extended jsonpath support (#266)

* Re #265 - Use extended JSONpath support,
Allow a JSONPath selector to not match anything (yet)
Adding test
Correctly capture invalid JSONPath query error

changedetectionio/forms.py

@@ -179,7 +179,7 @@ class ValidateCSSJSONInput(object):
     def __call__(self, form, field):
         if 'json:' in field.data:
             from jsonpath_ng.exceptions import JsonPathParserError, JsonPathLexerError
-            from jsonpath_ng import jsonpath, parse
+            from jsonpath_ng.ext import parse
 
             input = field.data.replace('json:', '')
 
@@ -189,6 +189,8 @@ class ValidateCSSJSONInput(object):
                 message = field.gettext('\'%s\' is not a valid JSONPath expression. (%s)')
                 raise ValidationError(message % (input, str(e)))
 
+            # Re #265 - maybe in the future fetch the page and offer a
+            # warning/notice that its possible the rule doesnt yet match anything?
 
 class quickWatchForm(Form):
     # https://wtforms.readthedocs.io/en/2.3.x/fields/#module-wtforms.fields.html5

changedetectionio/html_tools.py

@@ -1,6 +1,6 @@
 import json
 from bs4 import BeautifulSoup
-from jsonpath_ng import parse
+from jsonpath_ng.ext import parse
 
 
 class JSONNotFound(ValueError):
@@ -47,8 +47,8 @@ def _parse_json(json_data, jsonpath_filter):
 
     # Re #257 - Better handling where it does not exist, in the case the original 's' value was False..
     if not match:
-        # Maybe better to just allow it through, maybe they are waiting on a value to become available?
-        raise JSONNotFound("No Matching JSON could be found for the rule {}".format(jsonpath_filter.replace('json:', '')))
+        # Re 265 - Just return an empty string when filter not found
+        return ''
 
     stripped_text_from_html = json.dumps(s, indent=4)
 
@@ -87,6 +87,7 @@ def extract_json_as_string(content, jsonpath_filter):
                     break
 
     if not stripped_text_from_html:
-        raise JSONNotFound("No JSON matching the rule '%s' found" % jsonpath_filter.replace('json:',''))
+        # Re 265 - Just return an empty string when filter not found
+        return ''
 
     return stripped_text_from_html

changedetectionio/tests/test_jsonpath_selector.py

@@ -46,6 +46,45 @@ and it can also be repeated
     with pytest.raises(html_tools.JSONNotFound) as e_info:
         html_tools.extract_json_as_string('COMPLETE GIBBERISH, NO JSON!', "$.id")
 
+def set_original_ext_response():
+    data = """
+        [
+        {
+            "isPriceLowered": false,
+            "status": "ForSale",
+            "statusOrig": "for sale"
+        },
+        {
+            "_id": "5e7b3e1fb3262d306323ff1e",
+            "listingsType": "consumer",
+            "status": "ForSale",
+            "statusOrig": "for sale"
+        }
+    ]
+        """
+
+    with open("test-datastore/endpoint-content.txt", "w") as f:
+        f.write(data)
+
+def set_modified_ext_response():
+    data = """
+    [
+    {
+        "isPriceLowered": false,
+        "status": "Sold",
+        "statusOrig": "sold"
+    },
+    {
+        "_id": "5e7b3e1fb3262d306323ff1e",
+        "listingsType": "consumer",
+        "isPriceLowered": false,
+        "status": "Sold"
+    }
+]
+    """
+
+    with open("test-datastore/endpoint-content.txt", "w") as f:
+        f.write(data)
 
 def set_original_response():
     test_return_data = """
@@ -213,3 +252,76 @@ def test_check_json_filter_bool_val(client, live_server):
     res = client.get(url_for("diff_history_page", uuid="first"))
     # But the change should be there, tho its hard to test the change was detected because it will show old and new versions
     assert b'false' in res.data
+
+# Re #265 - Extended JSON selector test
+# Stuff to consider here
+# - Selector should be allowed to return empty when it doesnt match (people might wait for some condition)
+# - The 'diff' tab could show the old and new content
+# - Form should let us enter a selector that doesnt (yet) match anything
+def test_check_json_ext_filter(client, live_server):
+    json_filter = 'json:$[?(@.status==Sold)]'
+
+    set_original_ext_response()
+
+    # Give the endpoint time to spin up
+    time.sleep(1)
+
+    # Add our URL to the import page
+    test_url = url_for('test_endpoint', _external=True)
+    res = client.post(
+        url_for("import_page"),
+        data={"urls": test_url},
+        follow_redirects=True
+    )
+    assert b"1 Imported" in res.data
+
+    # Trigger a check
+    client.get(url_for("api_watch_checknow"), follow_redirects=True)
+
+    # Give the thread time to pick it up
+    time.sleep(3)
+
+    # Goto the edit page, add our ignore text
+    # Add our URL to the import page
+    res = client.post(
+        url_for("edit_page", uuid="first"),
+        data={"css_filter": json_filter,
+              "url": test_url,
+              "tag": "",
+              "headers": "",
+              "fetch_backend": "html_requests"
+              },
+        follow_redirects=True
+    )
+    assert b"Updated watch." in res.data
+
+    # Check it saved
+    res = client.get(
+        url_for("edit_page", uuid="first"),
+    )
+    assert bytes(json_filter.encode('utf-8')) in res.data
+
+    # Trigger a check
+    client.get(url_for("api_watch_checknow"), follow_redirects=True)
+
+    # Give the thread time to pick it up
+    time.sleep(3)
+    #  Make a change
+    set_modified_ext_response()
+
+    # Trigger a check
+    client.get(url_for("api_watch_checknow"), follow_redirects=True)
+    # Give the thread time to pick it up
+    time.sleep(4)
+
+    # It should have 'unviewed'
+    res = client.get(url_for("index"))
+    assert b'unviewed' in res.data
+
+    res = client.get(url_for("diff_history_page", uuid="first"))
+
+    # We should never see 'ForSale' because we are selecting on 'Sold' in the rule,
+    # But we should know it triggered ('unviewed' assert above)
+    assert b'ForSale' not in res.data
+    assert b'Sold' in res.data
+