Working

packages/geojson-inspector/src/index.ts

@@ -8,6 +8,8 @@
  * Learn more at https://developers.cloudflare.com/workers/
  */
 
+import { FailedInspectorResponse, InspectorResponse } from './types';
+
 export interface Env {
 	// Example binding to KV. Learn more at https://developers.cloudflare.com/workers/runtime-apis/kv/
 	// MY_KV_NAMESPACE: KVNamespace;
@@ -40,6 +42,113 @@ export default {
 			return new Response('Please provide a location', { status: 400 });
 		}
 		// https://uploads.seasketch.org/projects/cburt/public/4b08062c-9218-45d7-a00c-5147e103e02b.geojson.json
-		return new Response('Hello World!');
+		// fetch the geojson from the provided location
+		const startT = performance.now();
+		const response = await fetch(location, {
+			headers: {
+				accept: 'application/json',
+			},
+		});
+		const endT = performance.now();
+		let failedResponse: FailedInspectorResponse;
+
+		// if the fetch fails return an error
+		if (!response.ok) {
+			if (response.status === 404) {
+				failedResponse = {
+					location,
+					error: 'Server returned 404. Location not found',
+					errorsStatus: 404,
+				};
+			} else if (response.status >= 400 && response.status < 500) {
+				failedResponse = {
+					location,
+					error: 'Client error. Please check the location',
+					errorsStatus: response.status,
+				};
+			} else {
+				const text = await response.text();
+				failedResponse = {
+					location,
+					error: 'Server error. Could not retrieve data from location.\n' + text,
+					errorsStatus: response.status,
+				};
+			}
+			return new Response(JSON.stringify(failedResponse), {
+				status: 200,
+				headers: {
+					'Content-Type': 'application/json',
+					'Cache-Control': 'public, max-age=10, s-maxage=10',
+				},
+			});
+		} else {
+			const contentLength = response.headers.get('content-length');
+			const contentType = response.headers.get('content-type');
+			const cacheControl = response.headers.get('cache-control');
+			try {
+				const geojson: any = await response.json();
+				if (!('type' in geojson)) {
+					failedResponse = {
+						location,
+						error: 'Response is not a valid GeoJSON',
+						errorsStatus: 200,
+					};
+					return new Response(JSON.stringify(failedResponse), {
+						status: 200,
+						headers: {
+							'Content-Type': 'application/json',
+							'Cache-Control': 'public, max-age=10, s-maxage=10',
+						},
+					});
+				} else if (geojson.type !== 'FeatureCollection' && geojson.type !== 'Feature') {
+					failedResponse = {
+						location,
+						error: 'GeoJSON object must be a Feature or FeatureCollection',
+						errorsStatus: 200,
+					};
+					return new Response(JSON.stringify(failedResponse), {
+						status: 200,
+						headers: {
+							'Content-Type': 'application/json',
+							'Cache-Control': 'public, max-age=10, s-maxage=10',
+						},
+					});
+				} else {
+					const rootType = geojson.type;
+					return new Response(
+						JSON.stringify({
+							location,
+							contentLength: contentLength ? parseInt(contentLength) : 0,
+							contentType: contentType || '',
+							cacheControl: cacheControl || '',
+							latency: endT - startT,
+							rootType,
+							featureCount: rootType === 'FeatureCollection' ? geojson.features.length : 1,
+							geometryType: rootType === 'FeatureCollection' ? geojson.features[0]?.geometry?.type || 'Unknown' : geojson.geometry.type,
+						} as InspectorResponse),
+						{
+							status: 200,
+							headers: {
+								'Content-Type': 'application/json',
+								'Cache-Control': 'public, max-age=120, s-maxage=120',
+							},
+						}
+					);
+				}
+			} catch (e) {
+				failedResponse = {
+					location,
+					error: 'Failed to parse response as JSON',
+					errorsStatus: 200,
+				};
+				return new Response(JSON.stringify(failedResponse), {
+					status: 200,
+					headers: {
+						'Content-Type': 'application/json',
+						'Cache-Control': 'public, max-age=10, s-maxage=10',
+					},
+				});
+			}
+		}
 	},
 };

packages/geojson-inspector/src/types.ts

@@ -0,0 +1,24 @@
+interface BaseInspectorResponse {
+	location: string;
+}
+
+export interface FailedInspectorResponse extends BaseInspectorResponse {
+	error: string;
+	errorsStatus: number;
+}
+
+export interface SuccessfulInspectorResponse extends BaseInspectorResponse {
+	contentLength: number;
+	contentType: string;
+	cacheControl: string;
+	latency: number;
+	featureCount: number;
+	geometryType: 'Point' | 'MultiPoint' | 'LineString' | 'MultiLineString' | 'Polygon' | 'MultiPolygon';
+	rootType: 'FeatureCollection' | 'Feature';
+}
+
+export type InspectorResponse = FailedInspectorResponse | SuccessfulInspectorResponse;
+
+export function isSuccessfulInspectorResponse(response: InspectorResponse): response is SuccessfulInspectorResponse {
+	return (response as FailedInspectorResponse).error === undefined;
+}

packages/geojson-inspector/wrangler.toml

@@ -1,6 +1,8 @@
 name = "geojson-inspector"
 main = "src/index.ts"
 compatibility_date = "2024-02-08"
+# https://github.com/cloudflare/workerd/issues/787
+compatibility_flags = ["no_minimal_subrequests"]
 
 # Variable bindings. These are arbitrary, plaintext strings (similar to environment variables)
 # Note: Use secrets to store sensitive data.