FEATURE,PB_CHANGE: Add priceModifier for market priced listings.

Author: tyler-smith

api/jsonapi_test.go

@@ -306,6 +306,40 @@ func TestCryptoListings(t *testing.T) {
 	})
 }
 
+func TestCryptoListingsPriceModifier(t *testing.T) {
+	outOfRangeErr := core.ErrPriceModifierOutOfRange{
+		Min: core.PriceModifierMin,
+		Max: core.PriceModifierMax,
+	}
+
+	listing := factory.NewCryptoListing("crypto")
+	listing.Metadata.PriceModifier = core.PriceModifierMax
+	runAPITests(t, apiTests{
+		{"POST", "/ob/listing", jsonFor(t, listing), 200, `{"slug": "crypto"}`},
+		{"GET", "/ob/listing/crypto", jsonFor(t, listing), 200, anyResponseJSON},
+	})
+
+	listing.Metadata.PriceModifier = core.PriceModifierMax + 0.001
+	runAPITest(t, apiTest{
+		"POST", "/ob/listing", jsonFor(t, listing), 200, `{"slug": "crypto"}`,
+	})
+
+	listing.Metadata.PriceModifier = core.PriceModifierMax + 0.01
+	runAPITest(t, apiTest{
+		"POST", "/ob/listing", jsonFor(t, listing), 500, errorResponseJSON(outOfRangeErr),
+	})
+
+	listing.Metadata.PriceModifier = core.PriceModifierMin - 0.001
+	runAPITest(t, apiTest{
+		"POST", "/ob/listing", jsonFor(t, listing), 200, `{"slug": "crypto"}`,
+	})
+
+	listing.Metadata.PriceModifier = core.PriceModifierMin - 1
+	runAPITest(t, apiTest{
+		"POST", "/ob/listing", jsonFor(t, listing), 500, errorResponseJSON(outOfRangeErr),
+	})
+}
+
 func TestListingsQuantity(t *testing.T) {
 	listing := factory.NewListing("crypto")
 	runAPITest(t, apiTest{

core/errors.go

@@ -59,6 +59,15 @@ func (err ErrOutOfInventory) Error() string {
 	return string(jsonBytes)
 }
 
+type ErrPriceModifierOutOfRange struct {
+	Min float64
+	Max float64
+}
+
+func (e ErrPriceModifierOutOfRange) Error() string {
+	return fmt.Sprintf("priceModifier out of range: [%.2f, %.2f]", e.Min, e.Max)
+}
+
 type ErrCryptocurrencyListingIllegalField string
 
 func (e ErrCryptocurrencyListingIllegalField) Error() string {

core/listings.go

@@ -25,7 +25,7 @@ import (
 )
 
 const (
-	ListingVersion           = 3
+	ListingVersion           = 4
 	TitleMaxCharacters       = 140
 	ShortDescriptionLength   = 160
 	DescriptionMaxCharacters = 50000
@@ -43,13 +43,18 @@ const (
 	MaxCountryCodes          = 255
 	EscrowTimeout            = 1080
 	SlugBuffer               = 5
+	PriceModifierMin         = -99.99
+	PriceModifierMax         = 1000.00
 
 	DefaultCoinDivisibility uint32 = 1e8
+
+	priceModifierListingVersion = 4
 )
 
 type price struct {
-	CurrencyCode string `json:"currencyCode"`
-	Amount       uint64 `json:"amount"`
+	CurrencyCode string  `json:"currencyCode"`
+	Amount       uint64  `json:"amount"`
+	Modifier     float32 `json:"modifier"`
 }
 type thumbnail struct {
 	Tiny   string `json:"tiny"`
@@ -146,7 +151,7 @@ func (n *OpenBazaarNode) SignListing(listing *pb.Listing) (*pb.SignedListing, er
 	}
 
 	// Set listing version
-	listing.Metadata.Version = ListingVersion
+	listing.Metadata.Version = versionForNewListing(listing)
 
 	// Add the vendor ID to the listing
 	id := new(pb.ID)
@@ -442,16 +447,20 @@ func (n *OpenBazaarNode) extractListingData(listing *pb.SignedListing) (ListingD
 	}
 
 	ld := ListingData{
-		Hash:               listingHash,
-		Slug:               listing.Listing.Slug,
-		Title:              listing.Listing.Item.Title,
-		Categories:         listing.Listing.Item.Categories,
-		NSFW:               listing.Listing.Item.Nsfw,
-		CoinType:           listing.Listing.Metadata.CoinType,
-		ContractType:       listing.Listing.Metadata.ContractType.String(),
-		Description:        listing.Listing.Item.Description[:descriptionLength],
-		Thumbnail:          thumbnail{listing.Listing.Item.Images[0].Tiny, listing.Listing.Item.Images[0].Small, listing.Listing.Item.Images[0].Medium},
-		Price:              price{listing.Listing.Metadata.PricingCurrency, listing.Listing.Item.Price},
+		Hash:         listingHash,
+		Slug:         listing.Listing.Slug,
+		Title:        listing.Listing.Item.Title,
+		Categories:   listing.Listing.Item.Categories,
+		NSFW:         listing.Listing.Item.Nsfw,
+		CoinType:     listing.Listing.Metadata.CoinType,
+		ContractType: listing.Listing.Metadata.ContractType.String(),
+		Description:  listing.Listing.Item.Description[:descriptionLength],
+		Thumbnail:    thumbnail{listing.Listing.Item.Images[0].Tiny, listing.Listing.Item.Images[0].Small, listing.Listing.Item.Images[0].Medium},
+		Price: price{
+			CurrencyCode: listing.Listing.Metadata.PricingCurrency,
+			Amount:       listing.Listing.Item.Price,
+			Modifier:     listing.Listing.Metadata.PriceModifier,
+		},
 		ShipsTo:            shipsTo,
 		FreeShipping:       freeShipping,
 		Language:           listing.Listing.Metadata.Language,
@@ -1246,6 +1255,18 @@ func validateMarketPriceListing(listing *pb.Listing) error {
 		return ErrMarketPriceListingIllegalField("item.price")
 	}
 
+	if listing.Metadata.PriceModifier != 0 {
+		listing.Metadata.PriceModifier = float32(int(listing.Metadata.PriceModifier*100.0)) / 100.0
+	}
+
+	if listing.Metadata.PriceModifier < PriceModifierMin ||
+		listing.Metadata.PriceModifier > PriceModifierMax {
+		return ErrPriceModifierOutOfRange{
+			Min: PriceModifierMin,
+			Max: PriceModifierMax,
+		}
+	}
+
 	return nil
 }
 
@@ -1293,3 +1314,14 @@ func verifySignaturesOnListing(sl *pb.SignedListing) error {
 	}
 	return nil
 }
+
+func versionForNewListing(listing *pb.Listing) uint32 {
+	// Don't use newer version number of the listing doesn't have new features
+	if ListingVersion == priceModifierListingVersion &&
+		listing.Metadata.Format == pb.Listing_Metadata_MARKET_PRICE &&
+		listing.Metadata.PriceModifier != 0 {
+		return priceModifierListingVersion - 1
+	}
+
+	return ListingVersion
+}

core/order.go

@@ -819,6 +819,7 @@ func (n *OpenBazaarNode) CalculateOrderTotal(contract *pb.RicardianContract) (ui
 
 		if l.Metadata.Format == pb.Listing_Metadata_MARKET_PRICE {
 			satoshis, err = n.getMarketPriceInSatoshis(l.Metadata.CoinType, itemQuantity)
+			satoshis += uint64(float32(satoshis) * l.Metadata.PriceModifier / 100.0)
 			itemQuantity = 1
 		} else {
 			satoshis, err = n.getPriceInSatoshi(l.Metadata.PricingCurrency, l.Item.Price)