feat(csvimport): validated CSV account parser

internal/csvimport/csvimport.go

@@ -0,0 +1,56 @@
+package csvimport
+
+import (
+	"encoding/csv"
+	"fmt"
+	"io"
+	"strings"
+)
+
+type Row struct {
+	SrcLogin string
+	SrcPass  string
+	DstLogin string
+	DstPass  string
+}
+
+func Parse(r io.Reader) ([]Row, error) {
+	cr := csv.NewReader(r)
+	cr.FieldsPerRecord = -1 // проверяем сами
+	cr.TrimLeadingSpace = true
+
+	var rows []Row
+	seen := map[string]bool{}
+	line := 0
+	for {
+		rec, err := cr.Read()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+		line++
+		if len(rec) == 1 && strings.TrimSpace(rec[0]) == "" {
+			continue // пустая строка
+		}
+		if len(rec) != 4 {
+			return nil, fmt.Errorf("line %d: expected 4 columns, got %d", line, len(rec))
+		}
+		for i := range rec {
+			rec[i] = strings.TrimSpace(rec[i])
+			if rec[i] == "" {
+				return nil, fmt.Errorf("line %d: column %d is empty", line, i+1)
+			}
+		}
+		if seen[rec[0]] {
+			return nil, fmt.Errorf("line %d: duplicate src_login %q", line, rec[0])
+		}
+		seen[rec[0]] = true
+		rows = append(rows, Row{SrcLogin: rec[0], SrcPass: rec[1], DstLogin: rec[2], DstPass: rec[3]})
+	}
+	if len(rows) == 0 {
+		return nil, fmt.Errorf("no rows parsed")
+	}
+	return rows, nil
+}

internal/csvimport/csvimport_test.go

@@ -0,0 +1,34 @@
+package csvimport
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestParseOK(t *testing.T) {
+	rows, err := Parse(strings.NewReader("a@x,p1,a@y,p2\nb@x,p3,b@y,p4\n"))
+	if err != nil {
+		t.Fatalf("parse: %v", err)
+	}
+	if len(rows) != 2 || rows[0].SrcLogin != "a@x" || rows[1].DstPass != "p4" {
+		t.Fatalf("bad rows: %+v", rows)
+	}
+}
+
+func TestParseRejectsBadColumns(t *testing.T) {
+	if _, err := Parse(strings.NewReader("a,b,c\n")); err == nil {
+		t.Fatal("3 columns must error")
+	}
+}
+
+func TestParseRejectsDuplicateSrc(t *testing.T) {
+	if _, err := Parse(strings.NewReader("a@x,p,a@y,p\na@x,q,c@y,q\n")); err == nil {
+		t.Fatal("duplicate src_login must error")
+	}
+}
+
+func TestParseRejectsEmptyField(t *testing.T) {
+	if _, err := Parse(strings.NewReader("a@x,,a@y,p\n")); err == nil {
+		t.Fatal("empty password must error")
+	}
+}