Merge pull request #46 from camptocamp/ogc-api-avoid-stream-already-read

OGC API: Avoid "stream already consumed" errors on shared fetch calls

src/ogc-api/endpoint.spec.ts

@@ -43,6 +43,9 @@ beforeAll(() => {
     return {
       ok: true,
       headers: new Headers(),
+      clone: function () {
+        return this;
+      },
       json: () =>
         new Promise((resolve) => {
           resolve(JSON.parse(contents));
@@ -1633,7 +1636,8 @@ describe('OgcApiEndpoint', () => {
         await expect(endpoint.info).rejects.toEqual(
           new EndpointError(
             `The endpoint appears non-conforming, the following error was encountered:
-The document at http://local/sample-data/notjson?f=json does not appear to be valid JSON.`
+The document at http://local/sample-data/notjson?f=json does not appear to be valid JSON. Error was: Unexpected token 'h', "hello world
+" is not valid JSON`
           )
         );
       });

src/ogc-api/link-utils.ts

@@ -11,11 +11,14 @@ export function fetchDocument<T extends OgcApiDocument>(
     if (!resp.ok) {
       throw new Error(`The document at ${urlObj} could not be fetched.`);
     }
-    return resp.json().catch(() => {
-      throw new Error(
-        `The document at ${urlObj} does not appear to be valid JSON.`
-      );
-    }) as Promise<T>;
+    return resp
+      .clone()
+      .json()
+      .catch((e) => {
+        throw new Error(
+          `The document at ${urlObj} does not appear to be valid JSON. Error was: ${e.message}`
+        );
+      }) as Promise<T>;
   });
 }
 

src/shared/http-utils.spec.ts

@@ -34,7 +34,7 @@ describe('HTTP utils', () => {
     beforeAll(() => {
       fetchBehaviour = 'ok';
       originalFetch = global.fetch; // keep reference of native impl
-      global.fetch = jest.fn((xmlString, opts) => {
+      global.fetch = jest.fn().mockImplementation((xmlString, opts) => {
         const noCors = opts && opts.mode === 'no-cors';
         const headers = { get: () => null };
         switch (fetchBehaviour) {
@@ -45,12 +45,18 @@ describe('HTTP utils', () => {
               status: 200,
               ok: true,
               headers,
+              clone: function () {
+                return this;
+              },
             });
           case 'httpError':
             return Promise.resolve({
               text: () => Promise.resolve('<error>Random error</error>'),
               status: 401,
               ok: false,
+              clone: function () {
+                return this;
+              },
             });
           case 'corsError':
             if (noCors)
@@ -71,6 +77,9 @@ describe('HTTP utils', () => {
                     headers,
                     arrayBuffer: () =>
                       Promise.resolve(Buffer.from(sampleXml, 'utf-8')),
+                    clone: function () {
+                      return this;
+                    },
                   }),
                 10
               );

test-setup.ts

@@ -5,14 +5,14 @@ import * as util from 'util';
 import CacheMock from 'browser-cache-mock';
 import 'isomorphic-fetch';
 import { TextDecoder } from 'util';
-import { Buffer } from './node_modules/buffer';
+import { Buffer } from './node_modules/buffer/index.js';
 
 globalThis.Buffer = Buffer;
 
 // mock the global fetch API
 window.fetchResponseFactory = (url) => '<empty></empty>';
 window.originalFetch = window.fetch;
-window.mockFetch = jest.fn((url) =>
+window.mockFetch = jest.fn().mockImplementation((url) =>
   Promise.resolve({
     text: () => Promise.resolve(globalThis.fetchResponseFactory(url)),
     json: () =>
@@ -21,6 +21,9 @@ window.mockFetch = jest.fn((url) =>
       Promise.resolve(
         Buffer.from(globalThis.fetchResponseFactory(url), 'utf-8')
       ),
+    clone: function () {
+      return this;
+    },
     status: 200,
     ok: true,
     headers: { get: () => null },
@@ -43,9 +46,9 @@ window.caches = {
 global.Worker = function Worker(filePath) {
   let getScopeVar;
   let messageQueue = [];
-  let inside = mitt();
-  let outside = mitt();
-  let scope = {
+  const inside = mitt();
+  const outside = mitt();
+  const scope = {
     onmessage: null,
     dispatchEvent: inside.emit,
     addEventListener: inside.on,
@@ -57,7 +60,7 @@ global.Worker = function Worker(filePath) {
     importScripts() {},
   };
   inside.on('message', (e) => {
-    let f = scope.onmessage || getScopeVar('onmessage');
+    const f = scope.onmessage || getScopeVar('onmessage');
     if (f) f.call(scope, e);
   });
   this.addEventListener = outside.on;
@@ -88,14 +91,14 @@ global.Worker = function Worker(filePath) {
         result.outputFiles[0].contents
       );
       let vars = 'var self=this,global=self,globalThis=self';
-      for (let k in scope) vars += `,${k}=self.${k}`;
+      for (const k in scope) vars += `,${k}=self.${k}`;
       getScopeVar = Function(
         vars +
           ';\n' +
           code +
           '\nreturn function(n){return n=="onmessage"?onmessage:null;}'
       ).call(scope);
-      let q = messageQueue;
+      const q = messageQueue;
       messageQueue = null;
       q.forEach(this.postMessage);
     })