fix(gatsby-source-filesystem): fix unhandled rejection by returning promise chain (#14180)

Author: wardpeet

packages/gatsby-source-filesystem/src/__tests__/create-remote-file-node.js

@@ -104,6 +104,11 @@ describe(`create-remote-file-node`, () => {
         pipe: jest.fn(() => gotMock),
         on: jest.fn((mockType, mockCallback) => {
           if (mockType === type) {
+            // got throws on 404/500 so we mimic this behaviour
+            if (response.statusCode === 404) {
+              throw new Error(`Response code 404 (Not Found)`)
+            }
+
             mockCallback(response)
           }
 
@@ -177,7 +182,7 @@ describe(`create-remote-file-node`, () => {
         )
       })
 
-      it(`passes custom http heades, if defined`, async () => {
+      it(`passes custom http header, if defined`, async () => {
         await setup({
           httpHeaders: {
             Authorization: `Bearer foobar`,
@@ -193,6 +198,19 @@ describe(`create-remote-file-node`, () => {
           })
         )
       })
+
+      it(`fails when 404 is given`, async () => {
+        expect.assertions(1)
+        try {
+          await setup({}, `response`, { statusCode: 404 })
+        } catch (err) {
+          expect(err).toEqual(
+            expect.stringContaining(
+              `failed to process https://images.whatever.com/real-image-trust-me`
+            )
+          )
+        }
+      })
     })
   })
 

packages/gatsby-source-filesystem/src/create-remote-file-node.js

@@ -345,8 +345,11 @@ module.exports = ({
     name,
   })
 
-  fileDownloadPromise.then(() => bar.tick())
+  processingCache[url] = fileDownloadPromise.then(node => {
+    bar.tick()
 
-  processingCache[url] = fileDownloadPromise
-  return fileDownloadPromise
+    return node
+  })
+
+  return processingCache[url]
 }