Merge pull request #1 from obalunenko/develop

Implement validator

Author: obalunenko

.github/workflows/go.yml

@@ -0,0 +1,25 @@
+name: Go
+on: [push]
+jobs:
+  
+  vet-test:
+    name: Vet and test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Go 1.15
+        uses: actions/setup-go@v1
+        with:
+          go-version: 1.15
+        id: go
+      
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v1
+      
+      - name: Get dependencies
+        run: go mod verify
+      
+      - name: Vet
+        run: go vet $(go list ./...)
+      
+      - name: Test
+        run: go test -race -v $(go list ./...)

.gitignore

@@ -13,3 +13,6 @@
 
 # Dependency directories (remove the comment below to include it)
 # vendor/
+
+.idea/
+.vscode/

go.mod

@@ -0,0 +1,5 @@
+module github.com/obalunenko/csvvalidator
+
+go 1.15
+
+require github.com/stretchr/testify v1.7.0

go.sum

@@ -0,0 +1,11 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

validation.go

@@ -0,0 +1,133 @@
+// Package csvvalidator provide validation of csv rows according to set up rules.
+package csvvalidator
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// Column represents csv column.
+type Column struct {
+	Number uint
+	Name   string
+}
+
+// NewColumn creates new Column with passed column number,
+// name of column is optional.
+func NewColumn(number uint, name ...string) Column {
+	var resName string
+	if len(name) != 0 {
+		resName = strings.Join(name, " ")
+	}
+	return Column{
+		Number: number,
+		Name:   resName,
+	}
+
+}
+
+func (c *Column) String() string {
+	if c.Name == "" {
+		return fmt.Sprintf("%d", c.Number)
+	}
+	return fmt.Sprintf("%d:%s", c.Number, c.Name)
+}
+
+// Rule represent column row validation rule.
+type Rule struct {
+	MaxLength       uint // if 0 - no limit
+	MinLength       uint // if 0 - no limit
+	RestrictedChars []string
+}
+
+var (
+	// RuleNotEmpty defines a rule for field that require it to be not empty.
+	RuleNotEmpty = Rule{
+		MaxLength:       0,
+		MinLength:       1,
+		RestrictedChars: nil,
+	}
+	// RuleShouldBeEmpty defines a rule for field that require it to be empty.
+	RuleShouldBeEmpty = Rule{
+		MaxLength:       0,
+		MinLength:       0,
+		RestrictedChars: nil,
+	}
+)
+
+// ValidationRules represent rules for columns validation,
+// counting of columns in row starts from 0.
+type ValidationRules map[Column]Rule
+
+// Row represent csv row:
+// - total columns number for row
+// - validation rules for each column.
+type Row struct {
+	ColumnsTotalNum uint
+	ColumnsRules    ValidationRules
+}
+
+// ValidateRow validates passed row.
+func (row Row) ValidateRow(rec []string) error {
+	if row.ColumnsTotalNum == 0 {
+		return errors.New("invalid columns total number specified in rules")
+	}
+
+	if uint(len(rec)) != row.ColumnsTotalNum {
+		return fmt.Errorf("invalid row [row:[%v]; columns num:[%d]; should be: [%d]]",
+			rec,  len(rec), row.ColumnsTotalNum)
+	}
+
+	return row.ColumnsRules.ValidateRow(rec)
+}
+
+// ValidateRow validates passed row,
+// counting of columns in row starts from 0.
+func (rules ValidationRules) ValidateRow(rec []string) error {
+	if len(rules) == 0 {
+		return errors.New("validation rules not specified")
+	}
+	if len(rec) == 0 {
+		return errors.New("empty row")
+	}
+
+	for col, rule := range rules {
+		if err := validateColumn(rec[col.Number], rule); err != nil {
+			return fmt.Errorf("invalid column [row:%s; column:%s]: %w", rec,col.String(), err)
+		}
+	}
+
+	return nil
+}
+
+func validateColumn(data string, rule Rule) error {
+	if rule.MinLength != 0 && data == "" {
+		return errors.New("should not be empty")
+	}
+
+	if rule.MinLength == rule.MaxLength {
+		if uint(len(data)) != rule.MinLength {
+			return fmt.Errorf("invalid length [column:[%s]; has len:[%d]; should be:[%d]]",
+				data,len(data),rule.MinLength)
+		}
+	}
+
+	if uint(len(data)) < rule.MinLength {
+		return fmt.Errorf("invalid length [column:[%s]; has len:[%d]; should be at less[%d]]",
+			data, len(data),rule.MinLength)
+	}
+
+	if uint(len(data)) > rule.MaxLength && rule.MaxLength != 0 {
+		return fmt.Errorf("invalid length [column:[%s]; has len:[%d]; should be at less[%d]]",
+			data, len(data),rule.MaxLength)
+	}
+
+	if rule.RestrictedChars != nil {
+		if strings.ContainsAny(data, strings.Join(rule.RestrictedChars, "")) {
+			return fmt.Errorf("contains restricted characters [column:[%s]]", data)
+		}
+	}
+
+	return nil
+}

validation_example_test.go

@@ -0,0 +1,71 @@
+package csvvalidator_test
+
+import (
+	"fmt"
+
+	"github.com/obalunenko/csvvalidator"
+)
+
+func ExampleValidationRules_ValidateRow() {
+	// initialise columns
+	var (
+		clientNameCol        = csvvalidator.NewColumn(0, "Client Name")
+		transactionDateCol   = csvvalidator.NewColumn(1, "Transaction Date")
+		transactionAmountCol = csvvalidator.NewColumn(2, "Transaction Amount")
+		debitCreditCodeCol   = csvvalidator.NewColumn(3, "Debit Credit Code")
+		customerIDCol        = csvvalidator.NewColumn(4, "Customer ID")
+
+		// set total columns number
+		totalColNum = uint(5)
+	)
+
+	// set up validation rules
+	var rowRules = csvvalidator.ValidationRules{
+		clientNameCol: csvvalidator.Rule{
+			MaxLength:       4,
+			MinLength:       4,
+			RestrictedChars: nil,
+		},
+		transactionDateCol: csvvalidator.Rule{
+			MaxLength:       10,
+			MinLength:       10,
+			RestrictedChars: nil,
+		},
+		transactionAmountCol: csvvalidator.Rule{
+			MaxLength:       14,
+			MinLength:       4,
+			RestrictedChars: nil,
+		},
+		debitCreditCodeCol: csvvalidator.Rule{
+			MaxLength:       1,
+			MinLength:       1,
+			RestrictedChars: nil,
+		},
+		customerIDCol: csvvalidator.Rule{
+			MaxLength:       10,
+			MinLength:       1,
+			RestrictedChars: nil,
+		},
+	}
+
+	// create csv row ([]string)
+	var testDataRow = make([]string, totalColNum)
+	testDataRow[clientNameCol.Number] = "Test Client Name too long" // exceed maxlength
+	testDataRow[transactionDateCol.Number] = "2019/05/30"
+	testDataRow[transactionAmountCol.Number] = "100.45"
+	testDataRow[debitCreditCodeCol.Number] = "C"
+	testDataRow[customerIDCol.Number] = "ID"
+
+	// validate row
+	err := rowRules.ValidateRow(testDataRow)
+	fmt.Print(err)
+	// Output:
+	// invalid column [row:[Test Client Name too long 2019/05/30 100.45 C ID]; column:0:Client Name]: invalid length [column:[Test Client Name too long]; has len:[25]; should be:[4]]
+}
+
+func ExampleNewColumn() {
+	clientNameCol := csvvalidator.NewColumn(0, "Client Name")
+	fmt.Print(clientNameCol.String())
+	// Output:
+	// 0:Client Name
+}