import 'dart:convert';
import 'package:enough_mail/enough_mail.dart' as imap;
import 'package:flutter_test/flutter_test.dart';
import 'package:sharedinbox/core/utils/cid_utils.dart';
// A minimal multipart/related email with one embedded PNG referenced via cid:.
//
// The image data is the 1×1 red pixel PNG (67 bytes) from RFC-tests tradition.
const _kPixelPng =
'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwADhQGAWjR9awAAAABJRU5ErkJggg==';
// Build a synthetic RFC 2822 multipart/related message.
String _buildRelatedMime({String cidHost = 'test@example.com'}) {
const boundary = '----=_Part_TEST_BOUNDARY';
const innerBoundary = '----=_Part_INNER_BOUNDARY';
return [
'MIME-Version: 1.0',
'Content-Type: multipart/related;',
'\ttype="multipart/alternative";',
'\tboundary="$boundary"',
'',
'--$boundary',
'Content-Type: multipart/alternative;',
'\tboundary="$innerBoundary"',
'',
'--$innerBoundary',
'Content-Type: text/plain; charset=UTF-8',
'',
'See the image below.',
'--$innerBoundary',
'Content-Type: text/html; charset=UTF-8',
'',
'
',
'--$innerBoundary--',
'',
'--$boundary',
'Content-Type: image/png',
'Content-Disposition: inline',
'Content-Transfer-Encoding: base64',
'Content-ID: <$cidHost>',
'',
_kPixelPng,
'--$boundary--',
].join('\r\n');
}
void main() {
group('injectInlineImages', () {
test('replaces cid: reference with data: URI', () {
final msg = imap.MimeMessage.parseFromText(_buildRelatedMime());
const html = '
';
final result = injectInlineImages(html, msg);
expect(result, contains('src="data:image/png;base64,'));
expect(result, isNot(contains('cid:')));
});
test('leaves HTML unchanged when there are no inline parts', () {
// A plain text-only message.
const plainMime = 'MIME-Version: 1.0\r\n'
'Content-Type: text/plain\r\n'
'\r\n'
'Hello';
final msg = imap.MimeMessage.parseFromText(plainMime);
const html = '
';
expect(injectInlineImages(html, msg), html);
});
test('handles single-quoted src attribute', () {
final msg = imap.MimeMessage.parseFromText(_buildRelatedMime());
const html = "";
final result = injectInlineImages(html, msg);
expect(result, contains("src='data:image/png;base64,"));
expect(result, isNot(contains('cid:')));
});
test('embedded data is the same base64 as the MIME part', () {
final msg = imap.MimeMessage.parseFromText(_buildRelatedMime());
const html = '';
final result = injectInlineImages(html, msg);
// Extract base64 payload from the data URI.
final match = RegExp(
r'data:image/png;base64,([A-Za-z0-9+/=]+)',
).firstMatch(result);
expect(match, isNotNull);
final decoded = base64.decode(match!.group(1)!);
expect(decoded.length, greaterThan(0));
});
});
}