🔨 add debugging facility

functions/grapher/thumbnail/[slug].ts

@@ -6,10 +6,25 @@ export interface Env {
         fetch: typeof fetch
     }
     url: URL
+    ENV: string
 }
 
 const router = Router<IRequestStrict, [URL, Env, ExecutionContext]>()
 router
+    .get(
+        "/grapher/thumbnail/_debug",
+        async ({ params: {} }, { searchParams }, env) => {
+            console.log("Constructing debug info")
+            const info = {
+                url: env.url,
+                env: env.ENV,
+                searchParams: Array.from(searchParams.entries()),
+            }
+            return new Response(JSON.stringify(info), {
+                headers: { "Content-Type": "application/json" },
+            })
+        }
+    )
     .get(
         "/grapher/thumbnail/:slug.png",
         async ({ params: { slug } }, { searchParams }, env) =>
@@ -39,7 +54,11 @@ export const onRequestGet: PagesFunction = async (ctx) => {
         if (maybeCached) return maybeCached
     }
 
-    console.log("Handling", request.url, request.headers.get("User-Agent"))
+    console.log(
+        "Handling (with debug support)",
+        request.url,
+        request.headers.get("User-Agent")
+    )
 
     return router
         .fetch(request, url, { ...env, url }, ctx)

wrangler.toml

@@ -11,7 +11,7 @@ ENV = "development"
 [env.preview.vars]
 MAILGUN_DOMAIN = "mg.ourworldindata.org"
 SLACK_ERROR_CHANNEL_ID = "C016H0BNNB1"
-
+ENV = "preview"
 
 # Overrides for CF production deployment
 [env.production]