fix: make uploadFile throw for non-existent files

src/JSHandle.ts

@@ -291,7 +291,24 @@ export class ElementHandle extends JSHandle {
     // the cost unnecessarily.
     // eslint-disable-next-line @typescript-eslint/no-var-requires
     const path = require('path');
-    const files = filePaths.map(filePath => path.resolve(filePath));
+    // eslint-disable-next-line @typescript-eslint/no-var-requires
+    const fs = require('fs');
+    // eslint-disable-next-line @typescript-eslint/no-var-requires
+    const {promisify} = require('util');
+    const access = promisify(fs.access);
+
+    // Locate all files and confirm that they exist.
+    const files = await Promise.all(filePaths.map(async filePath => {
+      const resolvedPath: string = path.resolve(filePath);
+      try {
+        await access(resolvedPath, fs.constants.R_OK);
+      } catch (error) {
+        if (error.code === 'ENOENT')
+          throw new Error(`${filePath} does not exist or is not readable`);
+      }
+
+      return resolvedPath;
+    }));
     const {objectId} = this._remoteObject;
     const {node} = await this._client.send('DOM.describeNode', {objectId});
     const {backendNodeId} = node;

test/input.spec.js

@@ -184,6 +184,18 @@ describe('input tests', function() {
       ]).catch(e => error = e);
       expect(error).not.toBe(null);
     });
+    it('should fail for non-existent files', async() => {
+      const {page} = getTestState();
+
+      await page.setContent(`<input type=file>`);
+      const [chooser] = await Promise.all([
+        page.waitForFileChooser(),
+        page.click('input'),
+      ]);
+      let error = null;
+      await chooser.accept(['file-does-not-exist.txt']).catch(e => error = e);
+      expect(error).not.toBe(null);
+    });
     it('should fail when accepting file chooser twice', async() => {
       const {page} = getTestState();