add test for profit value/pct calculation; pct adjustments

hawk/src/main/java/io/irw/hawk/scraper/service/extractors/PriceExtractor.java

@@ -114,10 +114,10 @@ private static BigDecimal calculatePricePerPieceWithShipping(BigDecimal priceWit
  BigDecimal shippingCost) {
  return priceWithoutShipping
  .add(shippingCost)
- .divide(BigDecimal.valueOf(pieces), RoundingMode.HALF_UP);
+ .divide(BigDecimal.valueOf(pieces), 2, RoundingMode.HALF_UP);
  }
 
- private static BigDecimal calculateExpectedProfitUsd(BigDecimal pricePerPieceWithShipping,
+ protected static BigDecimal calculateExpectedProfitUsd(BigDecimal pricePerPieceWithShipping,
  BigDecimal referencePricePerPiece, Integer pieces,
  BigDecimal meestShippingAndHandlingOverhead) {
  return referencePricePerPiece
@@ -126,12 +126,14 @@ private static BigDecimal calculateExpectedProfitUsd(BigDecimal pricePerPieceWit
  .subtract(meestShippingAndHandlingOverhead);
  }
 
- private static BigDecimal calculateExpectedProfitPct(BigDecimal expectedProfitUsd, BigDecimal listingPriceUsd,
+ protected static BigDecimal calculateExpectedProfitPct(BigDecimal expectedProfitUsd, BigDecimal listingPriceUsd,
  BigDecimal shippingPriceUsd,
  BigDecimal meestShippingAndHandlingOverhead) {
  BigDecimal totalExpencesForListing = listingPriceUsd
  .add(shippingPriceUsd)
  .add(meestShippingAndHandlingOverhead);
- return expectedProfitUsd.divide(totalExpencesForListing, RoundingMode.HALF_DOWN);
+ return expectedProfitUsd
+ .multiply(BigDecimal.valueOf(100))
+ .divide(totalExpencesForListing, 2, RoundingMode.HALF_DOWN);
  }
 }

hawk/src/test/java/io/irw/hawk/scraper/service/extractors/PriceExtractorTest.java

@@ -0,0 +1,44 @@
+package io.irw.hawk.scraper.service.extractors;
+
+import static io.irw.hawk.scraper.service.extractors.PriceExtractor.calculateExpectedProfitPct;
+import static io.irw.hawk.scraper.service.extractors.PriceExtractor.calculateExpectedProfitUsd;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.math.BigDecimal;
+import org.assertj.core.data.Offset;
+import org.junit.jupiter.api.Test;
+
+class PriceExtractorTest {
+
+ public static final int LISTING_PRICE_PER_PIECE_USD = 5;
+ public static final int SHIPPING_PRICE_PER_PIECE_USD = 1;
+ public static final int MEEST_SH_OVERHEAD = 10;
+ public static final int NUMBER_OF_PIECES = 8;
+ public static final int USUAL_PRICE_PER_PIECE_USD = 9;
+ public static final double DELTA = 0.01;
+
+ @Test
+ void shouldCalculateExpectedProfitUsd() {
+ BigDecimal calculatedProfitUsd = calculateExpectedProfitUsd(
+ BigDecimal.valueOf(LISTING_PRICE_PER_PIECE_USD + SHIPPING_PRICE_PER_PIECE_USD),
+ BigDecimal.valueOf(USUAL_PRICE_PER_PIECE_USD), NUMBER_OF_PIECES, BigDecimal.valueOf(MEEST_SH_OVERHEAD));
+ double expectedProfitUsdValue = (USUAL_PRICE_PER_PIECE_USD * NUMBER_OF_PIECES
+ - (LISTING_PRICE_PER_PIECE_USD + SHIPPING_PRICE_PER_PIECE_USD) * NUMBER_OF_PIECES) - MEEST_SH_OVERHEAD;
+ assertThat(calculatedProfitUsd.doubleValue()).isEqualTo(expectedProfitUsdValue, Offset.offset(DELTA));
+ }
+
+ @Test
+ void shouldCalculateExpectedProfitPct() {
+ double expectedProfitUsd = USUAL_PRICE_PER_PIECE_USD * NUMBER_OF_PIECES
+ - (LISTING_PRICE_PER_PIECE_USD + SHIPPING_PRICE_PER_PIECE_USD) * NUMBER_OF_PIECES - MEEST_SH_OVERHEAD;
+ BigDecimal calculatedProfitPct = calculateExpectedProfitPct(BigDecimal.valueOf(expectedProfitUsd),
+ BigDecimal.valueOf(LISTING_PRICE_PER_PIECE_USD * NUMBER_OF_PIECES),
+ BigDecimal.valueOf(SHIPPING_PRICE_PER_PIECE_USD * NUMBER_OF_PIECES), BigDecimal.valueOf(MEEST_SH_OVERHEAD));
+
+ double expectedProfitPercentValue = (expectedProfitUsd /
+ ((LISTING_PRICE_PER_PIECE_USD + SHIPPING_PRICE_PER_PIECE_USD) * NUMBER_OF_PIECES + MEEST_SH_OVERHEAD))
+ * 100;
+ assertThat(calculatedProfitPct).matches(bigDecimal -> bigDecimal.compareTo(BigDecimal.ZERO) > 0);
+ assertThat(calculatedProfitPct.doubleValue()).isEqualTo(expectedProfitPercentValue, Offset.offset(DELTA));
+ }
+}