[gatsby-source-contentful] handle assets without files for improved preview api support (#3004)

* Handle Contentful Assets with no file

* Update image api queries to handle null file

Author: lsirivong

packages/gatsby-source-contentful/src/__tests__/__snapshots__/normalize.js.snap

@@ -1620,6 +1620,7 @@ Set {
   "wtrHxeu3zEoEce2MokCSi",
   "c10TkaLheGeQG6qQGqWYqUI",
   "c6s3iG2OVmoUcosmA8ocqsG",
+  "FAKE_ID_1phEMTm908mCCeYuSqCkyK",
 }
 `;
 
@@ -2197,6 +2198,36 @@ Array [
       "title": "House icon",
     },
   ],
+  Array [
+    Object {
+      "children": Array [],
+      "description": "",
+      "file": null,
+      "id": "FAKE_ID_1phEMTm908mCCeYuSqCkyK",
+      "internal": Object {
+        "contentDigest": "9cd202ba8ae3dd79494cd56c1ec453bc",
+        "type": "ContentfulAsset",
+      },
+      "node_locale": "en-US",
+      "parent": null,
+      "title": "",
+    },
+  ],
+  Array [
+    Object {
+      "children": Array [],
+      "description": "",
+      "file": null,
+      "id": "FAKE_ID_1phEMTm908mCCeYuSqCkyK___de",
+      "internal": Object {
+        "contentDigest": "b9803a73e3cb3df628b452fb0aa56e88",
+        "type": "ContentfulAsset",
+      },
+      "node_locale": "de",
+      "parent": null,
+      "title": "",
+    },
+  ],
 ]
 `;
 

packages/gatsby-source-contentful/src/__tests__/data.json

@@ -1866,6 +1866,24 @@
                         }
                     }
                 }
+            },
+            {
+              "sys": {
+                "space": {
+                  "sys": {
+                    "type": "Link",
+                    "linkType": "Space",
+                    "id": "rocybtov1ozk"
+                  }
+                },
+                "type": "Asset",
+                "id": "FAKE_ID_1phEMTm908mCCeYuSqCkyK",
+                "revision": 0,
+                "createdAt": "2017-11-16T20:47:42.248Z",
+                "updatedAt": "2017-11-16T20:47:42.248Z",
+                "locale": "en-US"
+              },
+              "fields": {}
             }
         ],
         "deletedEntries": [],

packages/gatsby-source-contentful/src/__tests__/extend-node-type.js

@@ -34,6 +34,12 @@ describe(`contentful extend node type`, () => {
       },
     },
   }
+
+  const nullFileImage = {
+    defaultLocale: `en-US`,
+    file: null,
+  }
+
   describe(`resolveResponsiveResolution`, () => {
     it(`generates responsive resolution data for images`, async () => {
       const resp = await resolveResponsiveResolution(image, { width: 400 })
@@ -72,6 +78,10 @@ describe(`contentful extend node type`, () => {
       expect(resp.width).toBe(450)
       expect(resp.height).toBe(399)
     })
+    it(`handles null`, async () => {
+      const resp = await resolveResponsiveResolution(nullFileImage, { width: 400 })
+      expect(resp).toBe(null)
+    })
   })
   describe(`resolveResponsiveSizes`, () => {
     it(`generates responsive size data for images`, async () => {
@@ -88,6 +98,10 @@ describe(`contentful extend node type`, () => {
       expect(resp.srcSet.length).toBeGreaterThan(1)
       expect(resp).toMatchSnapshot()
     })
+    it(`handles null`, async () => {
+      const resp = await resolveResponsiveSizes(nullFileImage, { maxWidth: 400 })
+      expect(resp).toBe(null)
+    })
   })
   describe(`resolveResize`, () => {
     it(`generates resized images`, async () => {
@@ -102,5 +116,9 @@ describe(`contentful extend node type`, () => {
       })
       expect(resp).toMatchSnapshot()
     })
+    it(`handles null`, async () => {
+      const resp = await resolveResize(nullFileImage, { width: 400 })
+      expect(resp).toBe(null)
+    })
   })
 })

packages/gatsby-source-contentful/src/extend-node-type.js

@@ -69,7 +69,7 @@ const ImageCropFocusType = new GraphQLEnumType({
 const isImage = image =>
   _.includes(
     [`image/jpeg`, `image/jpg`, `image/png`, `image/webp`, `image/gif`],
-    image.file.contentType
+    _.get(image, `file.contentType`)
   )
 
 const getBase64Image = (imgUrl, args = {}) => {
@@ -214,6 +214,7 @@ exports.resolveResponsiveResolution = resolveResponsiveResolution
 
 const resolveResponsiveSizes = (image, options) => {
   if (!isImage(image)) return null
+
   return new Promise(resolve => {
     getBase64ImageAndBasicMeasurements(image, options).then(
       ({ contentType, base64Str, width, height, aspectRatio }) => {
@@ -285,13 +286,10 @@ const resolveResponsiveSizes = (image, options) => {
 }
 exports.resolveResponsiveSizes = resolveResponsiveSizes
 
-const resolveResize = (image, options) =>
-  new Promise(resolve => {
-    if (!isImage(image)) {
-      resolve()
-      return
-    }
+const resolveResize = (image, options) => {
+  if (!isImage(image)) return null
 
+  return new Promise(resolve => {
     getBase64ImageAndBasicMeasurements(image, options).then(
       ({ contentType, base64Str, width, height, aspectRatio }) => {
         // If the user selected a height (so cropping) and fit option
@@ -324,6 +322,7 @@ const resolveResize = (image, options) =>
       }
     )
   })
+}
 
 exports.resolveResize = resolveResize
 

packages/gatsby-source-contentful/src/normalize.js

@@ -354,7 +354,9 @@ exports.createAssetNodes = ({
     //
     // Get localized fields.
     localizedAsset.fields = {
-      file: getField(localizedAsset.fields.file),
+      file: localizedAsset.fields.file 
+        ? getField(localizedAsset.fields.file)
+        : null,
       title: localizedAsset.fields.title
         ? getField(localizedAsset.fields.title)
         : ``,