lib/email: add an example for Filter method on Header

1 files changed, 62 insertions, 0 deletions

diff --git a/lib/email/header_example_test.go b/lib/email/header_example_test.go
new file mode 100644
index 00000000..2f4e36c4
--- /dev/null
+++ b/lib/email/header_example_test.go
@@ -0,0 +1,62 @@
+package email_test
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/shuLhan/share/lib/email"
+)
+
+func ExampleHeader_Filter() {
+	// Overwrite the email.Epoch to make the example works.
+	email.Epoch = func() int64 {
+		return 1645600000
+	}
+
+	var (
+		fromAddress = []byte("Noreply <noreply@example.com>")
+		toAddresses = []byte("John <john@example.com>, Jane <jane@example.com>")
+		subject     = []byte(`Example subject`)
+		bodyText    = []byte(`Email body as plain text`)
+		bodyHtml    = []byte(`Email body as <b>HTML</b>`)
+
+		recipients []string
+		mboxes     []*email.Mailbox
+		msg        *email.Message
+		err        error
+	)
+
+	mboxes, err = email.ParseMailboxes(toAddresses)
+	if err != nil {
+		log.Fatal(err)
+	}
+	for _, mbox := range mboxes {
+		recipients = append(recipients, mbox.Address)
+	}
+
+	msg, err = email.NewMultipart(
+		fromAddress,
+		toAddresses,
+		subject,
+		bodyText,
+		bodyHtml,
+	)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	_, _ = msg.Pack()
+
+	var (
+		fields []*email.Field
+		field  *email.Field
+	)
+
+	fields = msg.Header.Filter(email.FieldTypeFrom)
+
+	for _, field = range fields {
+		fmt.Printf("%s: %s\n", field.Name, field.Value)
+	}
+	// Output:
+	// from: Noreply <noreply@example.com>
+}