[SDP-1380] Allow disbursement.verification_field to be empty (#456)

### What

Allow disbursement.verification_field to be empty

### Why

Address https://stellarorg.atlassian.net/browse/SDP-1380

db/migrations/sdp-migrations/2024-11-01.1-disbursement-make-verification-field-nullable.sql

@@ -0,0 +1,7 @@
+-- This migration drops the verification_field NOT NULL constraint from the disbursements table.
+
+-- +migrate Up
+ALTER TABLE disbursements
+    ALTER COLUMN verification_field DROP NOT NULL;
+
+-- +migrate Down

internal/data/disbursements.go

@@ -14,6 +14,7 @@ import (
 	"github.com/stellar/go/support/log"
 
 	"github.com/stellar/stellar-disbursement-platform-backend/db"
+	"github.com/stellar/stellar-disbursement-platform-backend/internal/utils"
 )
 
 type Disbursement struct {
@@ -75,15 +76,15 @@ func (d *DisbursementModel) Insert(ctx context.Context, disbursement *Disburseme
 		VALUES 
 		    ($1, $2, $3, $4, $5, $6, $7, $8)
 		RETURNING id
-		    `
-	var newId string
-	err := d.dbConnectionPool.GetContext(ctx, &newId, q,
+	`
+	var newID string
+	err := d.dbConnectionPool.GetContext(ctx, &newID, q,
 		disbursement.Name,
 		disbursement.Status,
 		disbursement.StatusHistory,
 		disbursement.Wallet.ID,
 		disbursement.Asset.ID,
-		disbursement.VerificationField,
+		utils.SQLNullString(string(disbursement.VerificationField)),
 		disbursement.ReceiverRegistrationMessageTemplate,
 		disbursement.RegistrationContactType,
 	)
@@ -95,7 +96,7 @@ func (d *DisbursementModel) Insert(ctx context.Context, disbursement *Disburseme
 		return "", fmt.Errorf("unable to create disbursement %s: %w", disbursement.Name, err)
 	}
 
-	return newId, nil
+	return newID, nil
 }
 
 func (d *DisbursementModel) GetWithStatistics(ctx context.Context, id string) (*Disbursement, error) {
@@ -118,7 +119,7 @@ const selectDisbursementQuery = `
 			d.name,
 			d.status,
 			d.status_history,
-			d.verification_field,
+			COALESCE(d.verification_field::text, '') as verification_field,
 			COALESCE(d.file_name, '') as file_name,
 			d.file_content,
 			d.created_at,

internal/data/disbursements_test.go

@@ -15,7 +15,6 @@ import (
 func Test_DisbursementModelInsert(t *testing.T) {
 	dbt := dbtest.Open(t)
 	defer dbt.Close()
-
 	dbConnectionPool, err := db.OpenDBConnectionPool(dbt.DSN)
 	require.NoError(t, err)
 	defer dbConnectionPool.Close()
@@ -31,7 +30,7 @@ func Test_DisbursementModelInsert(t *testing.T) {
 	smsTemplate := "You have a new payment waiting for you from org x. Click on the link to register."
 
 	disbursement := Disbursement{
-		Name:   "disbursement1",
+		Name:   "disbursement",
 		Status: DraftDisbursementStatus,
 		StatusHistory: []DisbursementStatusHistoryEntry{
 			{
@@ -46,24 +45,27 @@ func Test_DisbursementModelInsert(t *testing.T) {
 		RegistrationContactType:             RegistrationContactTypePhone,
 	}
 
-	t.Run("returns error when disbursement already exists", func(t *testing.T) {
+	t.Run("🔴 fails to insert disbursements with non-unique name", func(t *testing.T) {
+		defer DeleteAllDisbursementFixtures(t, ctx, dbConnectionPool)
+
 		_, err := disbursementModel.Insert(ctx, &disbursement)
 		require.NoError(t, err)
 		_, err = disbursementModel.Insert(ctx, &disbursement)
 		require.Error(t, err)
 		require.Equal(t, ErrRecordAlreadyExists, err)
 	})
 
-	t.Run("insert disbursement successfully", func(t *testing.T) {
-		disbursement.Name = "disbursement2"
+	t.Run("🟢 successfully insert disbursement", func(t *testing.T) {
+		defer DeleteAllDisbursementFixtures(t, ctx, dbConnectionPool)
+
 		id, err := disbursementModel.Insert(ctx, &disbursement)
 		require.NoError(t, err)
 		require.NotNil(t, id)
 
 		actual, err := disbursementModel.Get(ctx, dbConnectionPool, id)
 		require.NoError(t, err)
 
-		assert.Equal(t, "disbursement2", actual.Name)
+		assert.Equal(t, "disbursement", actual.Name)
 		assert.Equal(t, DraftDisbursementStatus, actual.Status)
 		assert.Equal(t, asset, actual.Asset)
 		assert.Equal(t, wallet, actual.Wallet)
@@ -73,6 +75,31 @@ func Test_DisbursementModelInsert(t *testing.T) {
 		assert.Equal(t, "user1", actual.StatusHistory[0].UserID)
 		assert.Equal(t, VerificationTypeDateOfBirth, actual.VerificationField)
 	})
+
+	t.Run("🟢 successfully insert disbursement (empty:[VerificationField,ReceiverRegistrationMessageTemplate])", func(t *testing.T) {
+		defer DeleteAllDisbursementFixtures(t, ctx, dbConnectionPool)
+
+		d := disbursement
+		d.ReceiverRegistrationMessageTemplate = ""
+		d.VerificationField = ""
+
+		id, err := disbursementModel.Insert(ctx, &d)
+		require.NoError(t, err)
+		require.NotNil(t, id)
+
+		actual, err := disbursementModel.Get(ctx, dbConnectionPool, id)
+		require.NoError(t, err)
+
+		assert.Equal(t, "disbursement", actual.Name)
+		assert.Equal(t, DraftDisbursementStatus, actual.Status)
+		assert.Equal(t, asset, actual.Asset)
+		assert.Equal(t, wallet, actual.Wallet)
+		assert.Empty(t, actual.ReceiverRegistrationMessageTemplate)
+		assert.Equal(t, 1, len(actual.StatusHistory))
+		assert.Equal(t, DraftDisbursementStatus, actual.StatusHistory[0].Status)
+		assert.Equal(t, "user1", actual.StatusHistory[0].UserID)
+		assert.Empty(t, actual.VerificationField)
+	})
 }
 
 func Test_DisbursementModelCount(t *testing.T) {

internal/serve/httphandler/disbursement_handler.go

@@ -61,11 +61,13 @@ func (d DisbursementHandler) validateRequest(req PostDisbursementRequest) *valid
 		"registration_contact_type",
 		fmt.Sprintf("registration_contact_type must be one of %v", data.AllRegistrationContactTypes()),
 	)
-	v.Check(
-		slices.Contains(data.GetAllVerificationTypes(), req.VerificationField),
-		"verification_field",
-		fmt.Sprintf("verification_field must be one of %v", data.GetAllVerificationTypes()),
-	)
+	if !req.RegistrationContactType.IncludesWalletAddress {
+		v.Check(
+			slices.Contains(data.GetAllVerificationTypes(), req.VerificationField),
+			"verification_field",
+			fmt.Sprintf("verification_field must be one of %v", data.GetAllVerificationTypes()),
+		)
+	}
 
 	return v
 }

internal/serve/httphandler/disbursement_handler_test.go

@@ -38,11 +38,13 @@ import (
 )
 
 func Test_DisbursementHandler_validateRequest(t *testing.T) {
-	testCases := []struct {
+	type TestCase struct {
 		name           string
 		request        PostDisbursementRequest
 		expectedErrors map[string]interface{}
-	}{
+	}
+
+	testCases := []TestCase{
 		{
 			name:    "🔴 all fields are empty",
 			request: PostDisbursementRequest{},
@@ -82,6 +84,32 @@ func Test_DisbursementHandler_validateRequest(t *testing.T) {
 		},
 	}
 
+	for _, rct := range data.AllRegistrationContactTypes() {
+		var name string
+		var expectedErrors map[string]interface{}
+		if !rct.IncludesWalletAddress {
+			name = fmt.Sprintf("🔴[%s]registration_contact_type without wallet address REQUIRES verification_field", rct)
+			expectedErrors = map[string]interface{}{
+				"verification_field": fmt.Sprintf("verification_field must be one of %v", data.GetAllVerificationTypes()),
+			}
+		} else {
+			name = fmt.Sprintf("🟢[%s]registration_contact_type with wallet address DOES NOT REQUIRE registration_contact_type", rct)
+		}
+		newTestCase := TestCase{
+			name: name,
+			request: PostDisbursementRequest{
+				Name:                    "disbursement 1",
+				AssetID:                 "61dbfa89-943a-413c-b862-a2177384d321",
+				WalletID:                "aab4a4a9-2493-4f37-9741-01d5bd31d68b",
+				RegistrationContactType: rct,
+				VerificationField:       "",
+			},
+			expectedErrors: expectedErrors,
+		}
+
+		testCases = append(testCases, newTestCase)
+	}
+
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
 			handler := &DisbursementHandler{}

internal/utils/sql.go

@@ -0,0 +1,10 @@
+package utils
+
+import "database/sql"
+
+func SQLNullString(s string) sql.NullString {
+	return sql.NullString{
+		String: s,
+		Valid:  s != "",
+	}
+}