Follow the fucking spec. A '.' ain't no ','

2025-09-25 17:40:36 +01:00
3 changed files with 102 additions and 40 deletions
@@ -0,0 +1,12 @@
+version: "2"
+linters:
+  default: all
+  disable:
+    - wsl
+    - depguard
+    - varnamelen
+    - wrapcheck
+    - wsl_v5
+    - exhaustruct
+    - gochecknoglobals
+    - nlreturn
@@ -1,3 +1,7 @@
+// Package gofatqr offers a way to parse the QR code string from a portuguese
+// invoice. It's up to date with the tech specs
+// 'Portaria nº 195/2025 Versão 1.1 Outubro 2020'
+// https://info.portaldasfinancas.gov.pt/pt/apoio_contribuinte/Novas_regras_faturacao/Documents/Especificacoes_Tecnicas_Codigo_QR.pdf
 package gofatqr

 // TODO
@@ -14,9 +18,11 @@ import (
 	dec "github.com/shopspring/decimal"
 )

+// ScanMode defines the type used to configure stricter scanning and parsing of
+// the code.
 type ScanMode uint32

-// Setting this up for the future
+// Setting this up for the future.
 const (
 	Strict ScanMode = 1 << iota
 	NifValidation
@@ -27,6 +33,7 @@ const (
 	separator = "*"
 )

+// FiscalSpace Represents the each of the fiscal zones the invoice can have.
 type FiscalSpace struct {
 	TaxCountryRegion        string       `json:"TaxCountryRegion"`        // 1
 	TaxableBase             *dec.Decimal `json:"TaxableBase"`             // 2
@@ -38,6 +45,7 @@ type FiscalSpace struct {
 	VatTotalNormalBase      *dec.Decimal `json:"VatTotalNormalBase"`      // 8
 }

+// FatQR represents the data from the QR code of an invoice.
 type FatQR struct {
 	TaxRegistrationNumber string       `json:"TaxRegistrationNumber"` // A
 	CustomerTaxID         string       `json:"CustomerTaxID"`         // B
@@ -60,7 +68,7 @@ type FatQR struct {
 	OtherInfo             string       `json:"OtherInfo"`             // S
 }

-type FieldCodec struct {
+type fieldCodec struct {
 	Required bool
 	Parse    func(f *FatQR, val string) error
 	String   func(f *FatQR) string
@@ -77,7 +85,7 @@ var (
 	}
 )

-var fatQRFieldMap = map[string]FieldCodec{
+var fatQRFieldMap = map[string]fieldCodec{
 	"A": {
 		Required: true,
 		Parse: func(f *FatQR, val string) error {
@@ -191,8 +199,7 @@ var fatQRFieldMap = map[string]FieldCodec{
 	"H": {
 		Required: true,
 		Parse: func(f *FatQR, val string) error {
-			// TODO
-			// Add some ATCUD validation
+			// TODO - add some ATCUD validation
 			f.ATCUD = val
 			return nil
 		},
@@ -604,6 +611,10 @@ func parseDecimal(f **dec.Decimal, val string) error {
 	if *f == nil {
 		*f = new(dec.Decimal)
 	}
+
+	// Because software #2426 doesn't follow the spec correctly
+	val = strings.ReplaceAll(val, ",", ".")
+
 	return (*f).Scan(val)
 }

@@ -611,15 +622,51 @@ func stringDecimal(d *dec.Decimal) string {
 	return d.Truncate(decCount).StringFixed(decCount)
 }

+// ToJSON returns a []byte with the FatQR data as JSON.
 func (fq *FatQR) ToJSON() []byte {
 	jsondata, _ := json.Marshal(fq)
 	return jsondata
 }

+// FromJSON scans the data from a JSON []byte.
 func (fq *FatQR) FromJSON(data []byte) error {
 	return json.Unmarshal(data, fq)
 }

+// Scan scans a given string and applies the rules of `mode` (to be defined).
+//
+// returns an error if it fails to scan the given string.
+func (fq *FatQR) Scan(s string, _ ScanMode) error {
+	parts := strings.Split(s, "*")
+
+	err := fq.scanParts(parts)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (fq *FatQR) String() string {
+	parts := make([]string, 0, len(fieldOrder))
+
+	for _, key := range fieldOrder {
+		codec, ok := fatQRFieldMap[key]
+		if !ok {
+			panic("invalid key in order")
+		}
+
+		// TODO
+		// Using the flags I have to add, use it to enforce or not obligatory fields
+		// For now we are only going to stringify the data we have
+		if !codec.Empty(fq) {
+			parts = append(parts, codec.String(fq))
+		}
+	}
+
+	return strings.Join(parts, separator)
+}
+
 func (fq *FatQR) scanPart(part []string) error {
 	val, ok := fatQRFieldMap[part[0]]
 	if !ok {
@@ -649,35 +696,3 @@ func (fq *FatQR) scanParts(parts []string) error {

 	return nil
 }
-
-// Scan scans a given string and applies the rules of `mode` (to be defined)
-func (fq *FatQR) Scan(s string, mode ScanMode) error {
-	parts := strings.Split(s, "*")
-
-	err := fq.scanParts(parts)
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func (fq *FatQR) String() string {
-	parts := make([]string, 0, len(fieldOrder))
-
-	for _, key := range fieldOrder {
-		codec, ok := fatQRFieldMap[key]
-		if !ok {
-			panic("invalid key in order")
-		}
-
-		// TODO
-		// Using the flags I have to add, use it to enforce or not obligatory fields
-		// For now we are only going to stringify the data we have
-		if !codec.Empty(fq) {
-			parts = append(parts, codec.String(fq))
-		}
-	}
-
-	return strings.Join(parts, separator)
-}
@@ -13,12 +13,15 @@ func TestScan(t *testing.T) {
 	testCases := []struct {
 		name   string
 		input  string
+		output string // set output empty if its supposed to be equal to input
+		// once again, thanks to the fucking guys at 2426
 	}{
 		{
 			name: "5.0. Example 0 - Some invoice I had laying around",
 			input: "A:513847588*B:132772985*C:PT*D:FS*E:N*F:20250828*" +
 				"G:FS 437251001/115666*H:0*I1:PT*I7:37.94*I8:8.73*" +
 				"N:8.73*O:46.67*Q:mWUp*R:0177",
+			output: "",
 		},
 		{
 			name: "5.1. Example 1 - Invoice",
@@ -30,12 +33,14 @@ func TestScan(t *testing.T) {
 				"K5:25000.00*K6:3000.00*K7:40000.00*K8:8800.00*L:100.00*M:25.00*" +
 				"N:64000.02*O:513600.58*P:100.00*Q:kLp0*R:9999*" +
 				"S:TB;PT00000000000000000000000;513500.58",
+			output: "",
 		},
 		{
 			name: "5.2. Example 2 - Simplified Invoice",
 			input: "A:123456789*B:999999990*C:PT*D:FS*E:N*F:20190812*" +
 				"G:FS CDVF/12345*H:CDF7T5HD-12345*I1:PT*I7:0.65*I8:0.15*N:0.15*O:0.80*" +
 				"Q:YhGV*R:9999*S:NU;0.80",
+			output: "",
 		},
 		{
 			name: "5.3. Example 3 - Pro-form Invoice",
@@ -43,29 +48,54 @@ func TestScan(t *testing.T) {
 				"G:PF G2019CB/145789*H:HB6FT7RV-145789*I1:PT*I2:12345.34*I3:12532.65*" +
 				"I4:751.96*I5:52789.00*I6:6862.57*I7:32425.69*I8:7457.91*N:15072.44*" +
 				"O:125165.12*Q:r/fY*R:9999",
+			output: "",
 		},
 		{
 			name: "5.4. Example 4 - Transport Document",
 			input: "A:500000000*B:123456789*C:PT*D:GT*E:N*F:20190720*" +
 				"G:GT G234CB/50987*H:GTVX4Y8B-50987*I1:0*N:0.00*O:0.00*Q:5uIg*R:9999",
+			output: "",
 		},
 		{
 			name: "5.5. Example 5 - Invoice with foreign tax",
 			input: "A:123456789*B:4443332215*C:FR*D:FT*E:N*F:20190526*" +
 				"G:ABC BNH/4561*H:DK5ZJ2HN-4561*I1:FR*I7:100.00*I8:20.00*N:20.00*" +
 				"O:120.00*Q:YJRE*R:9999",
+			output: "",
 		},
 		{
 			name: "5.6. Example 6 - Tax Rectification Debit Note",
 			input: "A:123456789*B:500000000*C:PT*D:ND*E:N*F:20190216*" +
 				"G:M1F KLG/6145*H: RQD8L6DG-6145*I1:PT-MA*I6:26.50*N:26.50*O:26.50*" +
 				"Q:h1rB*R:9999",
+			output: "",
 		},
 		{
 			name: "5.7. Example 7 - Margin",
 			input: "A:500000000*B:123456789*C:PT*D:FT*E:N*F:20191124*" +
 				"G:NF 19A/789145*H:JL9DS4TT-789145*I1:PT-AC*I7:50.00*I8:9.00*L:1000.00*" +
 				"N:9.00*O:1059.00*Q:d8/K*R:9999",
+			output: "",
+		},
+		{
+			// Literally goes against the spec and we should be expecting failure here
+			name: "Some dev doesn't know how to read a spec file so periods are commas now",
+			input: "A:123456789*B:999999990*C:PT*D:FT*E:N*F:20191231*" +
+				"G:FT AB2019/0035*H:CSDF7T5H-0035*I1:PT*I2:12000,00*I3:15000,00*" +
+				"I4:900.00*I5:50000.00*I6:6500.00*I7:80000.00*I8:18400.00*J1:PT-AC*" +
+				"J2:10000.00*J3:25000.56*J4:1000.02*J5:75000.00*J6:6750,00*" +
+				"J7:100000.00*J8:18000.00*K1:PT-MA*K2:5000,00*K3:12500,00*K4:625.00*" +
+				"K5:25000.00*K6:3000,00*K7:40000,00*K8:8800,00*L:100.00*M:25.00*" +
+				"N:64000.02*O:513600.58*P:100.00*Q:kLp0*R:9999*" +
+				"S:TB;PT00000000000000000000000;513500.58",
+			output: "A:123456789*B:999999990*C:PT*D:FT*E:N*F:20191231*" +
+				"G:FT AB2019/0035*H:CSDF7T5H-0035*I1:PT*I2:12000.00*I3:15000.00*" +
+				"I4:900.00*I5:50000.00*I6:6500.00*I7:80000.00*I8:18400.00*J1:PT-AC*" +
+				"J2:10000.00*J3:25000.56*J4:1000.02*J5:75000.00*J6:6750.00*" +
+				"J7:100000.00*J8:18000.00*K1:PT-MA*K2:5000.00*K3:12500.00*K4:625.00*" +
+				"K5:25000.00*K6:3000.00*K7:40000.00*K8:8800.00*L:100.00*M:25.00*" +
+				"N:64000.02*O:513600.58*P:100.00*Q:kLp0*R:9999*" +
+				"S:TB;PT00000000000000000000000;513500.58",
 		},
 	}

@@ -77,8 +107,13 @@ func TestScan(t *testing.T) {
 			t.Errorf("Should not have occurred an error for: %s, %+v", tc.input, err)
 		}

+		expect := tc.input
+		if tc.output != "" {
+			expect = tc.output
+		}
+
 		stringified := qr.String()
-		if diff := cmp.Diff(tc.input, stringified); diff != "" {
+		if diff := cmp.Diff(expect, stringified); diff != "" {
 			t.Errorf("String mismatch (-want +got):\n%s", diff)
 		}
 	}