fix: filter non-file items out

Author: Roland Groza

src/file-selector.spec.ts

@@ -70,6 +70,14 @@ it('uses the DataTransfer {items} instead of {files} if it exists', async () =>
     expect(file.path).toBe(name);
 });
 
+it('skips DataTransfer {items} that are of kind "string"', async () => {
+    const item = dataTransferItemFromStr('test');
+    const evt = dragEvtFromItems(item);
+
+    const files = await fromEvent(evt);
+    expect(files).toHaveLength(0);
+});
+
 it('can read a tree of directories recursively and return a flat list of FileWithPath objects', async () => {
     const mockFiles = sortFiles([
         createFile('ping.json', {ping: true}),
@@ -124,8 +132,20 @@ function dataTransferItemFromFile(file: File): DataTransferItem {
         getAsFile() {
             return file;
         },
-        getAsString() {
+        // tslint:disable-next-line: no-empty
+        getAsString() {}
+    } as any;
+}
+
+function dataTransferItemFromStr(str: string): DataTransferItem {
+    return {
+        kind: 'string',
+        type: 'text/plain',
+        getAsFile() {
             return null;
+        },
+        getAsString(cb: (data: string) => void) {
+            return cb(str);
         }
     } as any;
 }

src/file-selector.ts

@@ -42,7 +42,10 @@ async function getDataTransferFiles(dt: DataTransfer) {
 // https://developer.mozilla.org/en-US/docs/Web/API/DataTransferItem
 function toFilePromises(item: DataTransferItem) {
     if (typeof item.webkitGetAsEntry !== 'function') {
-        return fromDataTransferItem(item);
+        if (item.kind === 'file') {
+            return fromDataTransferItem(item);
+        }
+        return [];
     }
 
     const entry = item.webkitGetAsEntry();

src/file.spec.ts

@@ -45,11 +45,15 @@ describe('toFile()', () => {
             type: 'application/json',
             lastModified: 1234567
         };
-        const file = new File([], 'test.json', opts);
+        const data = JSON.stringify({ping: true});
+        const file = new File([data], 'test.json', opts);
         const fwp = toFileWithPath(file);
 
         expect(fwp === file).toBe(false);
-        expect(fwp).toEqual(file);
+        expect(fwp.name).toEqual(file.name);
+        expect(fwp.type).toEqual(file.type);
+        expect(fwp.size).toEqual(file.size);
+        expect(fwp.lastModified).toEqual(file.lastModified);
     });
 
     it('should behave like a File', done => {

src/file.ts

@@ -45,7 +45,8 @@ function withMimeType(file: File) {
 }
 
 function clone(file: File, type?: string) {
-    return new File([file], file.name, {
+    const data = file.slice();
+    return new File([data], file.name, {
         lastModified: file.lastModified,
         type: type || file.type
     });