message: use class variable instead of global to track file upload contents
diff: @@ -20,7 +20,6 @@ const boxTarget = {
  }
  },
  };
  -let fileUploadContents = '';
  const EditYAMLComponent = DropTarget(NativeTypes.FILE, boxTarget, (connectObj, monitor) => ({
  connectDropTarget: connectObj.dropTarget(),
  @@ -30,6 +29,7 @@ const EditYAMLComponent = DropTarget(NativeTypes.FILE, boxTarget, (connectObj, m
  export const DroppableEditYAML = withDragDropContext<DroppableEditYAMLProps>(
  class DroppableEditYAML extends React.Component<DroppableEditYAMLProps, DroppableEditYAMLState> {
  + private fileUploadContents: string = '';
  constructor(props) {
  super(props);
  this.state = {
  @@ -41,9 +41,9 @@ export const DroppableEditYAML = withDragDropContext<DroppableEditYAMLProps>(
  }
  addDocument(newFileContent: string) {
  - fileUploadContents = _.isEmpty(fileUploadContents)
  + this.fileUploadContents = _.isEmpty(this.fileUploadContents)
  ? newFileContent
  - : `${fileUploadContents}\n---\n${newFileContent}`;
  + : `${this.fileUploadContents}\n---\n${newFileContent}`;
  }
  readFileContents(file, lastFile) {
  @@ -63,7 +63,7 @@ export const DroppableEditYAML = withDragDropContext<DroppableEditYAMLProps>(
  } else {
  this.addDocument(input.trim());
  if (lastFile) {
  - this.setState({ fileUpload: fileUploadContents });
  + this.setState({ fileUpload: this.fileUploadContents });
  }
  }
  };
  @@ -93,7 +93,7 @@ export const DroppableEditYAML = withDragDropContext<DroppableEditYAMLProps>(
  clearFileUpload() {
  this.setState({ fileUpload: '', errors: [] });
  - fileUploadContents = '';
  + this.fileUploadContents = '';
  }
  render() {
  