Feature: Display List-Unsubscribe & List-Unsubscribe-Post header info with syntax validation (#236)

internal/storage/database.go

@@ -405,6 +405,20 @@ func GetMessage(id string) (*Message, error) {
 		}
 	}
 
+	// get List-Unsubscribe links if set
+	obj.ListUnsubscribe = ListUnsubscribe{}
+	obj.ListUnsubscribe.Links = []string{}
+	if env.GetHeader("List-Unsubscribe") != "" {
+		l := env.GetHeader("List-Unsubscribe")
+		links, err := tools.ListUnsubscribeParser(l)
+		obj.ListUnsubscribe.Header = l
+		obj.ListUnsubscribe.Links = links
+		if err != nil {
+			obj.ListUnsubscribe.Errors = err.Error()
+		}
+		obj.ListUnsubscribe.HeaderPost = env.GetHeader("List-Unsubscribe-Post")
+	}
+
 	// mark message as read
 	if err := MarkRead(id); err != nil {
 		return &obj, err

internal/storage/structs.go

@@ -29,6 +29,9 @@ type Message struct {
 	ReturnPath string
 	// Message subject
 	Subject string
+	// List-Unsubscribe header information
+	// swagger:ignore
+	ListUnsubscribe ListUnsubscribe
 	// Message date if set, else date received
 	Date time.Time
 	// Message tags
@@ -122,3 +125,16 @@ func AttachmentSummary(a *enmime.Part) Attachment {
 
 	return o
 }
+
+// ListUnsubscribe contains a summary of List-Unsubscribe & List-Unsubscribe-Post headers
+// including validation of the link structure
+type ListUnsubscribe struct {
+	// List-Unsubscribe header value
+	Header string
+	// Detected links, maximum one email and one HTTP(S)
+	Links []string
+	// Validation errors if any
+	Errors string
+	// List-Unsubscribe-Post value if set
+	HeaderPost string
+}

internal/tools/listunsubscribeparser.go

@@ -0,0 +1,99 @@
+package tools
+
+import (
+	"fmt"
+	"net/url"
+	"regexp"
+	"strings"
+)
+
+// ListUnsubscribeParser will attempt to parse a `List-Unsubscribe` header and return
+// a slide of addresses (mail & URLs)
+func ListUnsubscribeParser(v string) ([]string, error) {
+	var results = []string{}
+	var re = regexp.MustCompile(`(?mU)<(.*)>`)
+	var reJoins = regexp.MustCompile(`(?imUs)>(.*)<`)
+	var reValidJoinChars = regexp.MustCompile(`(?imUs)^(\s+)?,(\s+)?$`)
+	var reWrapper = regexp.MustCompile(`(?imUs)^<(.*)>$`)
+	var reMailTo = regexp.MustCompile(`^mailto:[a-zA-Z0-9]`)
+	var reHTTP = regexp.MustCompile(`^(?i)https?://[a-zA-Z0-9]`)
+	var reSpaces = regexp.MustCompile(`\s`)
+	var reComments = regexp.MustCompile(`(?mUs)\(.*\)`)
+	var hasMailTo bool
+	var hasHTTP bool
+
+	v = strings.TrimSpace(v)
+
+	comments := reComments.FindAllStringSubmatch(v, -1)
+	for _, c := range comments {
+		// strip comments
+		v = strings.Replace(v, c[0], "", -1)
+		v = strings.TrimSpace(v)
+	}
+
+	if !re.MatchString(v) {
+		return results, fmt.Errorf("\"%s\" no valid unsubscribe links found", v)
+	}
+
+	errors := []string{}
+
+	if !reWrapper.MatchString(v) {
+		return results, fmt.Errorf("\"%s\" should be enclosed in <>", v)
+	}
+
+	matches := re.FindAllStringSubmatch(v, -1)
+
+	if len(matches) > 2 {
+		errors = append(errors, fmt.Sprintf("\"%s\" should include a maximum of one email and one HTTP link", v))
+	} else {
+		splits := reJoins.FindAllStringSubmatch(v, -1)
+		for _, g := range splits {
+			if !reValidJoinChars.MatchString(g[1]) {
+				return results, fmt.Errorf("\"%s\" <> should be split with a comma and optional spaces", v)
+			}
+		}
+
+		for _, m := range matches {
+			r := m[1]
+			if reSpaces.MatchString(r) {
+				errors = append(errors, fmt.Sprintf("\"%s\" should not contain spaces", r))
+				continue
+			}
+
+			if reMailTo.MatchString(r) {
+				if hasMailTo {
+					errors = append(errors, fmt.Sprintf("\"%s\" should only contain one mailto:", r))
+					continue
+				}
+
+				hasMailTo = true
+			} else if reHTTP.MatchString(r) {
+				if hasHTTP {
+					errors = append(errors, fmt.Sprintf("\"%s\" should only contain one HTTP link", r))
+					continue
+				}
+
+				hasHTTP = true
+
+			} else {
+				errors = append(errors, fmt.Sprintf("\"%s\" should start with either http(s):// or mailto:", r))
+				continue
+			}
+
+			_, err := url.ParseRequestURI(r)
+			if err != nil {
+				errors = append(errors, err.Error())
+				continue
+			}
+
+			results = append(results, r)
+		}
+	}
+
+	var err error
+	if len(errors) > 0 {
+		err = fmt.Errorf("%s", strings.Join(errors, ", "))
+	}
+
+	return results, err
+}

internal/tools/tools_test.go

@@ -69,3 +69,51 @@ func TestSnippets(t *testing.T) {
 		}
 	}
 }
+
+func TestListUnsubscribeParser(t *testing.T) {
+	tests := map[string]bool{}
+
+	// should pass
+	tests["<mailto:unsubscribe@example.com>"] = true
+	tests["<https://example.com>"] = true
+	tests["<HTTPS://EXAMPLE.COM>"] = true
+	tests["<mailto:unsubscribe@example.com>, <http://example.com>"] = true
+	tests["<mailto:unsubscribe@example.com>, <https://example.com>"] = true
+	tests["<https://example.com>, <mailto:unsubscribe@example.com>"] = true
+	tests["<https://example.com> , 		<mailto:unsubscribe@example.com>"] = true
+	tests["<https://example.com> ,<mailto:unsubscribe@example.com>"] = true
+	tests["<mailto:unsubscribe@example.com>,<https://example.com>"] = true
+	tests[`<https://example.com> ,
+		 <mailto:unsubscribe@example.com>`] = true
+	tests["<mailto:unsubscribe@example.com?subject=unsubscribe%20me>"] = true
+	tests["(Use this command to get off the list) <mailto:unsubscribe@example.com?subject=unsubscribe%20me>"] = true
+	tests["<mailto:unsubscribe@example.com> (Use this command to get off the list)"] = true
+	tests["(Use this command to get off the list) <mailto:unsubscribe@example.com>, (Click this link to unsubscribe) <http://example.com>"] = true
+
+	// should fail
+	tests["mailto:unsubscribe@example.com"] = false                                                // no <>
+	tests["<mailto::unsubscribe@example.com>"] = false                                             // ::
+	tests["https://example.com/"] = false                                                          // no <>
+	tests["mailto:unsubscribe@example.com, <https://example.com/>"] = false                        // no <>
+	tests["<MAILTO:unsubscribe@example.com>"] = false                                              // capitals
+	tests["<mailto:unsubscribe@example.com>, <mailto:test2@example.com>"] = false                  // two emails
+	tests["<http://exampl\\e2.com>, <http://example2.com>"] = false                                // two links
+	tests["<http://example.com>, <mailto:unsubscribe@example.com>, <http://example2.com>"] = false // two links
+	tests["<mailto:unsubscribe@example.com>, <example.com>"] = false                               // no mailto || http(s)
+	tests["<mailto: unsubscribe@example.com>, <unsubscribe@lol.com>"] = false                      // space
+	tests["<mailto:unsubscribe@example.com?subject=unsubscribe me>"] = false                       // space
+	tests["<http:///example.com>"] = false                                                         // http:///
+
+	for search, expected := range tests {
+		_, err := ListUnsubscribeParser(search)
+		hasError := err != nil
+		if expected == hasError {
+			if err != nil {
+				t.Logf("ListUnsubscribeParser: %v", err)
+			} else {
+				t.Logf("ListUnsubscribeParser: \"%s\" expected: %v", search, expected)
+			}
+			t.Fail()
+		}
+	}
+}

server/ui-src/assets/styles.scss

@@ -64,6 +64,11 @@
 	}
 }
 
+.link {
+	@extend a;
+	cursor: pointer;
+}
+
 .loader {
 	position: fixed;
 	top: 0;
@@ -154,6 +159,7 @@
 		padding-right: 1.5rem;
 		font-weight: normal;
 		vertical-align: top;
+		min-width: 120px;
 	}
 
 	td {

server/ui-src/components/message/Message.vue

@@ -7,6 +7,7 @@ import LinkCheck from './LinkCheck.vue'
 import SpamAssassin from './SpamAssassin.vue'
 import Prism from 'prismjs'
 import Tags from 'bootstrap5-tags'
+import { Tooltip } from 'bootstrap'
 import commonMixins from '../../mixins/CommonMixins'
 import { mailbox } from '../../stores/mailbox'
 
@@ -39,6 +40,7 @@ export default {
 			spamScore: false,
 			spamScoreColor: false,
 			showMobileButtons: false,
+			showUnsubscribe: false,
 			scaleHTMLPreview: 'display',
 			// keys names match bootstrap icon names 
 			responsiveSizes: {
@@ -121,6 +123,9 @@ export default {
 				})
 			})
 
+			const tooltipTriggerList = document.querySelectorAll('[data-bs-toggle="tooltip"]');
+			[...tooltipTriggerList].map(tooltipTriggerEl => new Tooltip(tooltipTriggerEl))
+
 			// delay 0.2s until vue has rendered the iframe content
 			window.setTimeout(function () {
 				let p = document.getElementById('preview-html')
@@ -244,12 +249,20 @@ export default {
 								<span v-else>
 									[ Unknown ]
 								</span>
+
+								<span v-if="message.ListUnsubscribe.Header != ''" class="small ms-3 link"
+									:title="showUnsubscribe ? 'Hide unsubscribe information' : 'Show unsubscribe information'"
+									@click="showUnsubscribe = !showUnsubscribe">
+									Unsubscribe
+									<i class="bi bi bi-info-circle"
+										:class="{ 'text-danger': message.ListUnsubscribe.Errors != '' }"></i>
+								</span>
 							</td>
 						</tr>
 						<tr class="small">
 							<th>To</th>
 							<td class="privacy">
-								<span v-if="message.To && message.To.length" v-for="(t, i) in message.To">
+								<span v-if="message.To && message.To.length" v-for="(   t, i   ) in    message.To   ">
 									<template v-if="i > 0">, </template>
 									<span>
 										<span class="text-spaces">{{ t.Name }}</span>
@@ -264,7 +277,7 @@ export default {
 						<tr v-if="message.Cc && message.Cc.length" class="small">
 							<th>Cc</th>
 							<td class="privacy">
-								<span v-for="(t, i) in message.Cc">
+								<span v-for="(   t, i   ) in    message.Cc   ">
 									<template v-if="i > 0">,</template>
 									<span class="text-spaces">{{ t.Name }}</span>
 									&lt;<a :href="searchURI(t.Address)" class="text-body">
@@ -276,7 +289,7 @@ export default {
 						<tr v-if="message.Bcc && message.Bcc.length" class="small">
 							<th>Bcc</th>
 							<td class="privacy">
-								<span v-for="(t, i) in message.Bcc">
+								<span v-for="(   t, i   ) in    message.Bcc   ">
 									<template v-if="i > 0">,</template>
 									<span class="text-spaces">{{ t.Name }}</span>
 									&lt;<a :href="searchURI(t.Address)" class="text-body">
@@ -288,7 +301,7 @@ export default {
 						<tr v-if="message.ReplyTo && message.ReplyTo.length" class="small">
 							<th class="text-nowrap">Reply-To</th>
 							<td class="privacy text-body-secondary text-break">
-								<span v-for="(t, i) in message.ReplyTo">
+								<span v-for="(   t, i   ) in    message.ReplyTo   ">
 									<template v-if="i > 0">,</template>
 									<span class="text-spaces">{{ t.Name }}</span>
 									&lt;<a :href="searchURI(t.Address)" class="text-body-secondary">
@@ -328,11 +341,34 @@ export default {
 									data-separator="|,|">
 									<option value="">Type a tag...</option>
 									<!-- you need at least one option with the placeholder -->
-									<option v-for="t in mailbox.tags" :value="t">{{ t }}</option>
+									<option v-for="   t    in    mailbox.tags   " :value="t">{{ t }}</option>
 								</select>
 								<div class="invalid-feedback">Invalid tag name</div>
 							</td>
 						</tr>
+
+						<tr v-if="message.ListUnsubscribe.Header != ''" class="small"
+							:class="showUnsubscribe ? '' : 'd-none'">
+							<th>Unsubscribe</th>
+							<td>
+								<span v-if="message.ListUnsubscribe.Links.length" class="text-secondary small me-2">
+									<template v-for="(u, i) in message.ListUnsubscribe.Links">
+										<template v-if="i > 0">, </template>
+										&lt;{{ u }}&gt;
+									</template>
+								</span>
+								<i class="bi bi-info-circle text-success me-2 link"
+									v-if="message.ListUnsubscribe.HeaderPost != ''" data-bs-toggle="tooltip"
+									data-bs-placement="top" data-bs-custom-class="custom-tooltip"
+									:data-bs-title="'List-Unsubscribe-Post: ' + message.ListUnsubscribe.HeaderPost">
+								</i>
+								<i class="bi bi-exclamation-circle text-danger link"
+									v-if="message.ListUnsubscribe.Errors != ''" data-bs-toggle="tooltip"
+									data-bs-placement="top" data-bs-custom-class="custom-tooltip"
+									:data-bs-title="message.ListUnsubscribe.Errors">
+								</i>
+							</td>
+						</tr>
 					</tbody>
 				</table>
 			</div>
@@ -455,7 +491,7 @@ export default {
 				</button>
 
 				<div class="d-none d-lg-block ms-auto me-3" v-if="showMobileButtons">
-					<template v-for="vals, key in responsiveSizes">
+					<template v-for="   vals, key    in    responsiveSizes   ">
 						<button class="btn" :disabled="scaleHTMLPreview == key" :title="'Switch to ' + key + ' view'"
 							v-on:click="scaleHTMLPreview = key">
 							<i class="bi" :class="'bi-' + key"></i>