Emit warning for unrecognised repo properties with our common prefix

src/feature-flags/properties.test.ts

@@ -4,7 +4,7 @@ import * as sinon from "sinon";
 import * as api from "../api-client";
 import { getRunnerLogger } from "../logging";
 import { parseRepositoryNwo } from "../repository";
-import { setupTests } from "../testing-utils";
+import { RecordingLogger, setupTests } from "../testing-utils";
 
 import * as properties from "./properties";
 
@@ -197,3 +197,38 @@ test.serial(
     );
   },
 );
+
+test.serial(
+  "loadPropertiesFromApi warns if a repository property name starts with the common prefix, but is not recognised by us",
+  async (t) => {
+    process.env["GITHUB_EVENT_NAME"] = "push";
+    const propertyName: string = `${properties.GITHUB_CODEQL_PROPERTY_PREFIX}unknown`;
+    sinon.stub(api, "getRepositoryProperties").resolves({
+      headers: {},
+      status: 200,
+      url: "",
+      data: [
+        {
+          property_name: propertyName,
+          value: "true",
+        },
+      ] satisfies properties.GitHubPropertiesResponse,
+    });
+    const logger = new RecordingLogger();
+    const warningSpy = sinon.spy(logger, "warning");
+    const mockRepositoryNwo = parseRepositoryNwo("owner/repo");
+    const response = await properties.loadPropertiesFromApi(
+      logger,
+      mockRepositoryNwo,
+    );
+    t.deepEqual(response, {});
+    t.true(warningSpy.calledOnce);
+    t.assert(
+      warningSpy.firstCall.args[0]
+        .toString()
+        .startsWith(
+          `Found repository properties ('${propertyName}'), which look like CodeQL Action repository properties`,
+        ),
+    );
+  },
+);

src/feature-flags/properties.ts

@@ -1,7 +1,11 @@
+import { isDynamicWorkflow } from "../actions-util";
 import { getRepositoryProperties } from "../api-client";
 import { Logger } from "../logging";
 import { RepositoryNwo } from "../repository";
 
+/** The common prefix that we expect all of our repository properties to have. */
+export const GITHUB_CODEQL_PROPERTY_PREFIX = "github-codeql-";
+
 /**
  * Enumerates repository property names that have some meaning to us.
  */
@@ -114,6 +118,8 @@ export async function loadPropertiesFromApi(
     );
 
     const properties: RepositoryProperties = {};
+    const unrecognisedProperties: string[] = [];
+
     for (const property of remoteProperties) {
       if (property.property_name === undefined) {
         throw new Error(
@@ -123,6 +129,11 @@ export async function loadPropertiesFromApi(
 
       if (isKnownPropertyName(property.property_name)) {
         setProperty(properties, property.property_name, property.value, logger);
+      } else if (
+        property.property_name.startsWith(GITHUB_CODEQL_PROPERTY_PREFIX) &&
+        !isDynamicWorkflow()
+      ) {
+        unrecognisedProperties.push(property.property_name);
       }
     }
 
@@ -139,6 +150,20 @@ export async function loadPropertiesFromApi(
       }
     }
 
+    // Emit a warning if we encountered unrecognised properties that have our prefix.
+    if (unrecognisedProperties.length > 0) {
+      const unrecognisedPropertyList = unrecognisedProperties
+        .map((name) => `'${name}'`)
+        .join(", ");
+
+      logger.warning(
+        `Found repository properties (${unrecognisedPropertyList}), ` +
+          "which look like CodeQL Action repository properties, " +
+          "but which are not understood by this version of the CodeQL Action. " +
+          "Do you need to update to a newer version?",
+      );
+    }
+
     return properties;
   } catch (e) {
     throw new Error(