Initial commit

.travis.yml

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+language: go
+
+go:
+  - 1.x
+
+script:
+  - go test -race -coverprofile=coverage.txt -covermode=atomic
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)

LICENSE

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+MIT License
+
+Copyright (c) 2018 Igor German
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+## DED (Disposable Email Detector)
+
+[![Build Status](https://www.travis-ci.org/namreg/ded.svg?branch=master)](https://www.travis-ci.org/namreg/ded)
+[![Go Report Card](https://goreportcard.com/badge/github.com/namreg/ded)](https://goreportcard.com/report/github.com/namreg/ded)
+[![GitHub](https://img.shields.io/github/license/mashape/apistatus.svg)](https://github.com/namreg/ded/blob/master/LICENSE)
+[![GoDoc](https://godoc.org/github.com/namreg/ded?status.svg)](https://godoc.org/github.com/namreg/ded)

ded.go

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+package ded
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+	"sync"
+)
+
+//ErrEmailMalformed error returns when email is not valid.
+var ErrEmailMalformed = errors.New("ded: email malformed")
+
+//IsDisposableEmail checks whether the given email is disposable.
+func IsDisposableEmail(email string) (bool, error) {
+	parts := strings.SplitN(email, "@", 2)
+	if len(parts) != 2 {
+		return false, ErrEmailMalformed
+	}
+	return IsDisposableDomain(parts[1])
+}
+
+//IsDisposableDomain checks whether the given domain is disposable.
+func IsDisposableDomain(domain string) (bool, error) {
+	domains.once.Do(func() { domains.loadFromFile("domains.txt") })
+	if domains.err != nil {
+		return false, domains.err
+	}
+	domain = strings.TrimSpace(domain)
+	return domains.has(normalizeString(domain)), nil
+}
+
+func normalizeString(str string) string {
+	return strings.ToLower(strings.TrimSpace(str))
+}
+
+var domains = new(collection)
+
+type collection struct {
+	items map[string]struct{}
+	err   error
+	once  sync.Once
+}
+
+func (c *collection) has(item string) bool {
+	_, ok := c.items[item]
+	return ok
+}
+
+func (c *collection) loadFromFile(filename string) {
+	f, err := os.Open(filename)
+	if err != nil {
+		c.err = fmt.Errorf("ded: could not open %q file: %v", filename, err)
+		return
+	}
+	c.items = make(map[string]struct{})
+
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		domain := normalizeString(s.Text())
+		if domain == "" {
+			continue
+		}
+		c.items[domain] = struct{}{}
+	}
+
+	if err := s.Err(); err != nil {
+		c.err = fmt.Errorf("ded: scanner error: %v", err)
+	}
+}

ded_test.go

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+package ded
+
+import (
+	"testing"
+)
+
+func TestIsDisposableEmail(t *testing.T) {
+	tests := []struct {
+		name    string
+		email   string
+		want    bool
+		wantErr error
+	}{
+		{"not disposable email", "[email protected]", false, nil},
+		{"disposable email", "[email protected]", true, nil},
+		{"ignore spaces", "   [email protected]   ", true, nil},
+		{"case insensitive", "[email protected]", true, nil},
+		{"malformed email", "eml.com", false, ErrEmailMalformed},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := IsDisposableEmail(tt.email)
+			if err != tt.wantErr {
+				t.Fatalf("IsDisposableEmail() error = %v, wantErr %v", err, tt.wantErr)
+			}
+			if got != tt.want {
+				t.Fatalf("IsDisposableEmail() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestIsDisposableDomain(t *testing.T) {
+	tests := []struct {
+		name    string
+		domain  string
+		want    bool
+		wantErr error
+	}{
+		{"not disposable domain", "google.com", false, nil},
+		{"disposable domain", "mail.wtf", true, nil},
+		{"ignore spaces", "   mail.wtf   ", true, nil},
+		{"case insensitive", "MAIL.wtf", true, nil},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := IsDisposableDomain(tt.domain)
+			if err != tt.wantErr {
+				t.Fatalf("TestIsDisposableDomain() error = %v, wantErr %v", err, tt.wantErr)
+			}
+			if got != tt.want {
+				t.Fatalf("TestIsDisposableDomain() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}