add some error wrapping to indicate file problems

src/logic/import/voc/VOCImporter.ts

@@ -13,6 +13,21 @@ type VOCImportResult = {
  fileParseResults: FileParseResult[],
 };
 
+class DocumentParsingError extends Error {
+ constructor(message?: string) {
+ super(message);
+ this.name = "DocumentParsingError";
+ }
+}
+class AnnotationParsingError extends Error {
+ constructor(message?: string) {
+ super(message);
+ this.name = "AnnotationParsingError";
+ }
+}
+
+const parser = new DOMParser();
+
 export class VOCImporter extends AnnotationImporter {
  public import(
  filesData: File[],
@@ -40,31 +55,54 @@ export class VOCImporter extends AnnotationImporter {
  }
 
  private loadAndParseFiles(files: File[]): Promise<VOCImportResult> {
- const parser = new DOMParser();
-
  return Promise.all(files.map((file: File) => file.text())).then((fileTexts: string[]) => 
- fileTexts.reduce((current: VOCImportResult, fileText: string) => 
- VOCImporter.parseDocumentIntoImageData(parser.parseFromString(fileText, 'application/xml'), current), 
- {
- labelNames: {},
- fileParseResults: [],
- } as VOCImportResult)
+ fileTexts.reduce((current: VOCImportResult, fileText: string, currentIndex: number) => 
+ {
+ const fileName = files[currentIndex].name;
+ try {
+ return VOCImporter.parseDocumentIntoImageData(VOCImporter.tryParseVOCDocument(fileText), current);
+ } catch (e) {
+ if (e instanceof DocumentParsingError) {
+ throw new DocumentParsingError(`Failed trying to parse ${fileName} as VOC XML document.`)
+ } else if (e instanceof AnnotationParsingError) {
+ throw new AnnotationParsingError(`Failed trying to find required VOC annotations for ${fileName}.`)
+ } else {
+ throw e;
+ }
+ }
+ }, 
+ {
+ labelNames: {},
+ fileParseResults: [],
+ } as VOCImportResult)
  );
  }
 
+ private static tryParseVOCDocument(fileText: string): Document {
+ try {
+ return parser.parseFromString(fileText, 'application/xml');
+ } catch {
+ throw new DocumentParsingError();
+ }
+ }
+
  protected static parseDocumentIntoImageData(document: Document, { fileParseResults, labelNames }: VOCImportResult): VOCImportResult {
  const root = document.getElementsByTagName('annotation')[0];
  const filename = root.getElementsByTagName('filename')[0].textContent;
 
- const [labeledBoxes, newLabelNames] = this.parseAnnotationsFromFileString(document, labelNames);
+ try {
+ const [labeledBoxes, newLabelNames] = this.parseAnnotationsFromFileString(document, labelNames);
 
- return {
- labelNames: newLabelNames,
- fileParseResults: fileParseResults.concat({
- filename,
- labeledBoxes
- }),
- };
+ return {
+ labelNames: newLabelNames,
+ fileParseResults: fileParseResults.concat({
+ filename,
+ labeledBoxes
+ }),
+ };
+ } catch {
+ throw new AnnotationParsingError();
+ }
  }
 
  protected static parseAnnotationsFromFileString(document: Document, labelNames: Record<string, LabelName>):