improve: extract a price when it is prefixed with "US$"

Author: php-coder

src/main/java/ru/mystamps/web/feature/series/importing/SeriesInfoExtractorServiceImpl.java

@@ -435,6 +435,8 @@ public SeriesExtractedInfo extract(String pageUrl, RawParsedDataDto data) {
 		if (matcher.find()) {
 			fragment = matcher.replaceAll("$1$2");
 		}
+
+		String prefix = "US$";
 
 		String[] candidates = StringUtils.split(fragment, ' ');
 		for (String candidate : candidates) {
@@ -446,6 +448,10 @@ public SeriesExtractedInfo extract(String pageUrl, RawParsedDataDto data) {
 			if (candidate.endsWith("$") && candidate.length() >= 2) {
 				candidate = candidate.substring(0, candidate.length() - 1);
 			}
+			// "US$10" -> "10"
+			if (candidate.startsWith(prefix) && candidate.length() > prefix.length()) {
+				candidate = StringUtils.substringAfter(candidate, prefix);
+			}
 			try {
 				BigDecimal price = new BigDecimal(candidate);
 				log.debug("Price is {}", price);

src/test/groovy/ru/mystamps/web/feature/series/importing/SeriesInfoExtractorServiceImplTest.groovy

@@ -647,13 +647,15 @@ class SeriesInfoExtractorServiceImplTest extends Specification {
 	}
 
 	@Unroll
+	@SuppressWarnings('UnnecessaryBigDecimalInstantiation')
 	def 'extractPrice() should extract "#expected" from "#fragment"'(String fragment, BigDecimal expected) {
 		expect:
 			service.extractPrice(fragment) == expected
 		where:
 			fragment        | expected
 			'1$'            | BigDecimal.ONE
 			'10$'           | BigDecimal.TEN
+			'US$16.50'      | new BigDecimal('16.50')
 			'10 EUR'        | BigDecimal.TEN
 			'10.0 EUR'      | BigDecimal.TEN
 			'10.00 EUR'     | BigDecimal.TEN