Fix TestNewImageAttachment tests

In particular, this will support audio attachments.

Ref T872

activitystreams/activity.go

@@ -117,6 +117,7 @@ type Object struct {
 	Content      string            `json:"content"`
 	ContentMap   map[string]string `json:"contentMap,omitempty"`
 	Tag          []Tag             `json:"tag"`
+	Attachment   []Attachment      `json:"attachment,omitempty"`
 
 	// Extensions
 	// NOTE: add extensions here

activitystreams/attachment.go

@@ -0,0 +1,47 @@
+package activitystreams
+
+import (
+	"mime"
+	"strings"
+)
+
+type Attachment struct {
+	Type      AttachmentType `json:"type"`
+	URL       string         `json:"url"`
+	MediaType string         `json:"mediaType"`
+	Name      string         `json:"name"`
+}
+
+type AttachmentType string
+
+const (
+	AttachImage    AttachmentType = "Image"
+	AttachDocument AttachmentType = "Document"
+)
+
+// NewImageAttachment creates a new Attachment from the given URL, setting the
+// correct type and automatically detecting the MediaType based on the file
+// extension.
+func NewImageAttachment(url string) Attachment {
+	return newAttachment(url, AttachImage)
+}
+
+// NewDocumentAttachment creates a new Attachment from the given URL, setting the
+// correct type and automatically detecting the MediaType based on the file
+// extension.
+func NewDocumentAttachment(url string) Attachment {
+	return newAttachment(url, AttachDocument)
+}
+
+func newAttachment(url string, attachType AttachmentType) Attachment {
+	var fileType string
+	extIdx := strings.LastIndexByte(url, '.')
+	if extIdx > -1 {
+		fileType = mime.TypeByExtension(url[extIdx:])
+	}
+	return Attachment{
+		Type:      attachType,
+		URL:       url,
+		MediaType: fileType,
+	}
+}

activitystreams/attachment_test.go

@@ -0,0 +1,64 @@
+package activitystreams
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestNewImageAttachment(t *testing.T) {
+	type args struct {
+		url string
+	}
+	tests := []struct {
+		name string
+		args args
+		want Attachment
+	}{
+		{name: "good svg", args: args{"https://writefreely.org/img/writefreely.svg"}, want: Attachment{
+			Type:      "Image",
+			URL:       "https://writefreely.org/img/writefreely.svg",
+			MediaType: "image/svg+xml",
+		}},
+		{name: "good png", args: args{"https://i.snap.as/12345678.png"}, want: Attachment{
+			Type:      "Image",
+			URL:       "https://i.snap.as/12345678.png",
+			MediaType: "image/png",
+		}},
+		{name: "no extension", args: args{"https://i.snap.as/12345678"}, want: Attachment{
+			Type:      "Image",
+			URL:       "https://i.snap.as/12345678",
+			MediaType: "",
+		}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := NewImageAttachment(tt.args.url); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("NewImageAttachment() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestNewDocumentAttachment(t *testing.T) {
+	type args struct {
+		url string
+	}
+	tests := []struct {
+		name string
+		args args
+		want Attachment
+	}{
+		{name: "mp3", args: args{"https://listen.as/matt/abc.mp3"}, want: Attachment{
+			Type:      "Document",
+			URL:       "https://listen.as/matt/abc.mp3",
+			MediaType: "audio/mpeg",
+		}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := NewDocumentAttachment(tt.args.url); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("NewDocumentAttachment() = %+v, want %+v", got, tt.want)
+			}
+		})
+	}
+}

activitystreams/tag.go

@@ -10,5 +10,5 @@ type TagType string
 
 const (
 	TagHashtag TagType = "Hashtag"
-	TagMention         = "Mention"
+	TagMention TagType = "Mention"
 )

auth/auth.go

@@ -1,7 +1,7 @@
 package auth
 
 import (
-	uuid "github.com/nu7hatch/gouuid"
+	uuid "github.com/gofrs/uuid"
 	"github.com/writeas/web-core/log"
 	"strings"
 )
@@ -16,7 +16,7 @@ func GetToken(header string) []byte {
 			token = f[1]
 		}
 	}
-	t, err := uuid.ParseHex(token)
+	t, err := uuid.FromString(token)
 	if err != nil {
 		log.Error("Couldn't parseHex on '%s': %v", accessToken, err)
 	} else {
@@ -31,7 +31,7 @@ func GetHeaderToken(header string) []byte {
 	if len(header) > 0 {
 		f := strings.Fields(header)
 		if len(f) == 2 && f[0] == "Token" {
-			t, err := uuid.ParseHex(f[1])
+			t, err := uuid.FromString(f[1])
 			if err != nil {
 				log.Error("Couldn't parseHex on '%s': %v", accessToken, err)
 			} else {

go.mod

@@ -3,16 +3,15 @@ module github.com/writeas/web-core
 go 1.10
 
 require (
-	github.com/kr/pretty v0.1.0 // indirect
+	github.com/gofrs/uuid v3.3.0+incompatible
 	github.com/kylemcc/twitter-text-go v0.0.0-20180726194232-7f582f6736ec
 	github.com/microcosm-cc/bluemonday v1.0.2
-	github.com/nu7hatch/gouuid v0.0.0-20131221200532-179d4d0c4d8d
 	github.com/shurcooL/sanitized_anchor_name v1.0.0 // indirect
-	github.com/writeas/impart v1.1.0
+	github.com/writeas/go-strip-markdown v2.0.1+incompatible
-	github.com/writeas/nerds v1.0.0
+	github.com/writeas/impart v1.1.1
 	github.com/writeas/openssl-go v1.0.0
-	github.com/writeas/saturday v1.6.0
+	github.com/writeas/saturday v1.7.1
-	golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613
+	golang.org/x/crypto v0.0.0-20200109152110-61a87790db17
-	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
+	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v1 v1.0.0-20140924161607-9f9df34309c0 // indirect
 )

go.sum

@@ -1,5 +1,7 @@
-github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/gofrs/uuid v3.3.0+incompatible h1:8K4tyRfvU1CYPgJsveYFQMhpFd/wXNM7iK6rR7UHz84=
-github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/gofrs/uuid v3.3.0+incompatible/go.mod h1:b2aQJv3Z4Fp6yNu3cdSllBxTCLRxnplIgP/c0N/04lM=
+github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
+github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
@@ -7,23 +9,27 @@ github.com/kylemcc/twitter-text-go v0.0.0-20180726194232-7f582f6736ec h1:ZXWuspq
 github.com/kylemcc/twitter-text-go v0.0.0-20180726194232-7f582f6736ec/go.mod h1:voECJzdraJmolzPBgL9Z7ANwXf4oMXaTCsIkdiPpR/g=
 github.com/microcosm-cc/bluemonday v1.0.2 h1:5lPfLTTAvAbtS0VqT+94yOtFnGfUWYyx0+iToC3Os3s=
 github.com/microcosm-cc/bluemonday v1.0.2/go.mod h1:iVP4YcDBq+n/5fb23BhYFvIMq/leAFZyRl6bYmGDlGc=
-github.com/nu7hatch/gouuid v0.0.0-20131221200532-179d4d0c4d8d h1:VhgPp6v9qf9Agr/56bj7Y/xa04UccTW04VP0Qed4vnQ=
-github.com/nu7hatch/gouuid v0.0.0-20131221200532-179d4d0c4d8d/go.mod h1:YUTz3bUH2ZwIWBy3CJBeOBEugqcmXREj14T+iG/4k4U=
 github.com/shurcooL/sanitized_anchor_name v1.0.0 h1:PdmoCO6wvbs+7yrJyMORt4/BmY5IYyJwS/kOiWx8mHo=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
-github.com/writeas/impart v1.1.0 h1:nPnoO211VscNkp/gnzir5UwCDEvdHThL5uELU60NFSE=
+github.com/writeas/go-strip-markdown v2.0.1+incompatible h1:IIqxTM5Jr7RzhigcL6FkrCNfXkvbR+Nbu1ls48pXYcw=
-github.com/writeas/impart v1.1.0/go.mod h1:g0MpxdnTOHHrl+Ca/2oMXUHJ0PcRAEWtkCzYCJUXC9Y=
+github.com/writeas/go-strip-markdown v2.0.1+incompatible/go.mod h1:Rsyu10ZhbEK9pXdk8V6MVnZmTzRG0alMNLMwa0J01fE=
-github.com/writeas/nerds v1.0.0 h1:ZzRcCN+Sr3MWID7o/x1cr1ZbLvdpej9Y1/Ho+JKlqxo=
+github.com/writeas/impart v1.1.1 h1:RyA9+CqbdbDuz53k+nXCWUY+NlEkdyw6+nWanxSBl5o=
-github.com/writeas/nerds v1.0.0/go.mod h1:Gn2bHy1EwRcpXeB7ZhVmuUwiweK0e+JllNf66gvNLdU=
+github.com/writeas/impart v1.1.1/go.mod h1:g0MpxdnTOHHrl+Ca/2oMXUHJ0PcRAEWtkCzYCJUXC9Y=
 github.com/writeas/openssl-go v1.0.0 h1:YXM1tDXeYOlTyJjoMlYLQH1xOloUimSR1WMF8kjFc5o=
 github.com/writeas/openssl-go v1.0.0/go.mod h1:WsKeK5jYl0B5y8ggOmtVjbmb+3rEGqSD25TppjJnETA=
-github.com/writeas/saturday v1.6.0 h1:HNUtX8TVJJnSdxE8vaAgtHiAJVt+Of5AJYlm62pmVlI=
+github.com/writeas/saturday v1.7.1 h1:lYo1EH6CYyrFObQoA9RNWHVlpZA5iYL5Opxo7PYAnZE=
-github.com/writeas/saturday v1.6.0/go.mod h1:ETE1EK6ogxptJpAgUbcJD0prAtX48bSloie80+tvnzQ=
+github.com/writeas/saturday v1.7.1/go.mod h1:ETE1EK6ogxptJpAgUbcJD0prAtX48bSloie80+tvnzQ=
-golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613 h1:MQ/ZZiDsUapFFiMS+vzwXkCTeEKaum+Do5rINYJDmxc=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/crypto v0.0.0-20200109152110-61a87790db17 h1:nVJ3guKA9qdkEQ3TUdXI9QSINo2CUPM/cySEvw2w8I0=
+golang.org/x/crypto v0.0.0-20200109152110-61a87790db17/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/net v0.0.0-20181220203305-927f97764cc3 h1:eH6Eip3UpmR+yM/qI9Ijluzb1bNv/cAU/n+6l8tRSis=
 golang.org/x/net v0.0.0-20181220203305-927f97764cc3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
-gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v1 v1.0.0-20140924161607-9f9df34309c0 h1:POO/ycCATvegFmVuPpQzZFJ+pGZeX22Ufu6fibxDVjU=
 gopkg.in/yaml.v1 v1.0.0-20140924161607-9f9df34309c0/go.mod h1:WDnlLJ4WF5VGsH/HVa3CI79GS0ol3YnhVnKP89i0kNg=

id/random.go

@@ -1,12 +1,38 @@
 package id
 
 import (
+	"crypto/rand"
 	"fmt"
-	"github.com/writeas/nerds/store"
 )
 
+// GenerateRandomString creates a random string of characters of the given
+// length from the given dictionary of possible characters.
+//
+// This example generates a hexadecimal string 6 characters long:
+//     GenerateRandomString("0123456789abcdef", 6)
+func GenerateRandomString(dictionary string, l int) string {
+	var bytes = make([]byte, l)
+	rand.Read(bytes)
+	for k, v := range bytes {
+		bytes[k] = dictionary[v%byte(len(dictionary))]
+	}
+	return string(bytes)
+}
+
 // GenSafeUniqueSlug generatees a reasonably unique random slug from the given
 // original slug. It's "safe" because it uses 0-9 b-z excluding vowels.
 func GenSafeUniqueSlug(slug string) string {
-	return fmt.Sprintf("%s-%s", slug, store.GenerateRandomString("0123456789bcdfghjklmnpqrstvwxyz", 4))
+	return fmt.Sprintf("%s-%s", slug, GenerateRandomString("0123456789bcdfghjklmnpqrstvwxyz", 4))
+}
+
+// Generate62RandomString creates a random string with the given length
+// consisting of characters in [A-Za-z0-9].
+func Generate62RandomString(l int) string {
+	return GenerateRandomString("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz", l)
+}
+
+// GenerateFriendlyRandomString creates a random string of characters with the
+// given length consisting of characters in [a-z0-9].
+func GenerateFriendlyRandomString(l int) string {
+	return GenerateRandomString("0123456789abcdefghijklmnopqrstuvwxyz", l)
 }

l10n/phrases_zh.go

@@ -3,24 +3,24 @@ package l10n
 var phrasesZH = map[string]string{
 	"Anonymous post":                 "匿名文章",
 	"Blogs":                          "博客",
-	"Enter":                          "按下Enter按钮",
+	"Enter":                          "按下回车",
-	"Newer":                          "最近的博客",
+	"Newer":                          "更新",
-	"Older":                          "之前的博客",
+	"Older":                          "较旧",
 	"Posts":                          "文章",
 	"Publish to...":                  "发布到...",
 	"Publish":                        "发布",
 	"Read more...":                   "阅读更多",
-	"This blog requires a password.": "这篇博客需要密码",
+	"This blog requires a password.": "这篇文章需要密码",
 	"Toggle theme":                   "更换主题",
 	"View posts":                     "查看文章",
 	"delete":                         "删除",
 	"edit":                           "编辑",
 	"move to...":                     "移动到",
 	"pin":                            "固定文章",
-	"published with write.as":  "用write.as来发布",
+	"published with write.as":  "通过 write.as 发布",
-	"share modal ending":       "发送给朋友，或者线上分享，如果可能的话，分享到推特上。了解更多。",
+	"share modal ending":       "发送给朋友、与世界分享或者发条推。了解更多。",
-	"share modal introduction": "发布的每篇文章都有一个唯一的私有URL，你可以把它分享给任何人。这是URL：",
+	"share modal introduction": "发布的每篇文章都有一个唯一的私有网址，你可以把它分享给任何人：",
-	"share modal title":        "分享这篇文章",
+	"share modal title":        "分享文章",
 	"share":                    "分享",
 	"unpin":                    "取消固定",
 }

memo/memo.go

@@ -67,3 +67,13 @@ func (memo *Memo) Get() (value interface{}, err error) {
 	}
 	return memo.cache.res.value, memo.cache.res.err
 }
+
+// Reset forcibly resets the cache to nil without checking if the cache
+// duration has elapsed.
+func (memo *Memo) Reset() {
+	defer memo.mu.Unlock()
+	memo.mu.Lock()
+
+	memo.cache = nil
+	memo.lastCache = time.Now()
+}

posts/parse.go

@@ -1,7 +1,24 @@
 package posts
 
 import (
+	"fmt"
+	stripmd "github.com/writeas/go-strip-markdown"
+	"github.com/writeas/web-core/stringmanip"
+	"regexp"
 	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+const (
+	maxTitleLen     = 80
+	assumedTitleLen = 80
+)
+
+var (
+	titleElementReg = regexp.MustCompile("</?p>")
+	urlReg          = regexp.MustCompile("https?://")
+	imgReg          = regexp.MustCompile(`!\[([^]]+)\]\([^)]+\)`)
 )
 
 // ExtractTitle takes the given raw post text and returns a title, if explicitly
@@ -19,3 +36,130 @@ func ExtractTitle(content string) (title string, body string) {
 	body = content
 	return
 }
+
+func FriendlyPostTitle(content, friendlyId string) string {
+	content = StripHTMLWithoutEscaping(content)
+
+	content = strings.TrimLeftFunc(stripmd.Strip(content), unicode.IsSpace)
+	eol := strings.IndexRune(content, '\n')
+	blankLine := strings.Index(content, "\n\n")
+	if blankLine != -1 && blankLine <= eol && blankLine <= assumedTitleLen {
+		return strings.TrimSpace(content[:blankLine])
+	} else if eol == -1 && utf8.RuneCountInString(content) <= maxTitleLen {
+		return content
+	}
+
+	title, truncd := TruncToWord(PostLede(content, true), maxTitleLen)
+	if truncd {
+		title += "..."
+	}
+	return title
+}
+
+// PostDescription generates a description based on the given post content,
+// title, and post ID. This doesn't consider a V2 post field, `title` when
+// choosing what to generate. In case a post has a title, this function will
+// fail, and logic should instead be implemented to skip this when there's no
+// title, like so:
+//    var desc string
+//    if title == "" {
+//        desc = PostDescription(content, title, friendlyId)
+//    } else {
+//        desc = ShortPostDescription(content)
+//    }
+func PostDescription(content, title, friendlyId string) string {
+	maxLen := 140
+
+	if content == "" {
+		content = "WriteFreely is a painless, simple, federated blogging platform."
+	} else {
+		fmtStr := "%s"
+		truncation := 0
+		if utf8.RuneCountInString(content) > maxLen {
+			// Post is longer than the max description, so let's show a better description
+			fmtStr = "%s..."
+			truncation = 3
+		}
+
+		if title == friendlyId {
+			// No specific title was found; simply truncate the post, starting at the beginning
+			content = fmt.Sprintf(fmtStr, strings.Replace(stringmanip.Substring(content, 0, maxLen-truncation), "\n", " ", -1))
+		} else {
+			// There was a title, so return a real description
+			blankLine := strings.Index(content, "\n\n")
+			if blankLine < 0 {
+				blankLine = 0
+			}
+			truncd := stringmanip.Substring(content, blankLine, blankLine+maxLen-truncation)
+			contentNoNL := strings.Replace(truncd, "\n", " ", -1)
+			content = strings.TrimSpace(fmt.Sprintf(fmtStr, contentNoNL))
+		}
+	}
+
+	return content
+}
+
+func ShortPostDescription(content string) string {
+	maxLen := 140
+	fmtStr := "%s"
+	truncation := 0
+	if utf8.RuneCountInString(content) > maxLen {
+		// Post is longer than the max description, so let's show a better description
+		fmtStr = "%s..."
+		truncation = 3
+	}
+	return strings.TrimSpace(fmt.Sprintf(fmtStr, strings.Replace(stringmanip.Substring(content, 0, maxLen-truncation), "\n", " ", -1)))
+}
+
+// TruncToWord truncates the given text to the provided limit.
+func TruncToWord(s string, l int) (string, bool) {
+	truncated := false
+	c := []rune(s)
+	if len(c) > l {
+		truncated = true
+		s = string(c[:l])
+		spaceIdx := strings.LastIndexByte(s, ' ')
+		if spaceIdx > -1 {
+			s = s[:spaceIdx]
+		}
+	}
+	return s, truncated
+}
+
+// PostLede attempts to extract the first thought of the given post, generally
+// contained within the first line or sentence of text.
+func PostLede(t string, includePunc bool) string {
+	// Adjust where we truncate if we want to include punctuation
+	iAdj := 0
+	if includePunc {
+		iAdj = 1
+	}
+
+	// Find lede within first line of text
+	nl := strings.IndexRune(t, '\n')
+	if nl > -1 {
+		t = t[:nl]
+	}
+
+	// Strip certain HTML tags
+	t = titleElementReg.ReplaceAllString(t, "")
+
+	// Strip URL protocols
+	t = urlReg.ReplaceAllString(t, "")
+
+	// Strip image URL, leaving only alt text
+	t = imgReg.ReplaceAllString(t, " $1 ")
+
+	// Find lede within first sentence
+	punc := strings.Index(t, ". ")
+	if punc > -1 {
+		t = t[:punc+iAdj]
+	}
+	punc = stringmanip.IndexRune(t, '。')
+	if punc > -1 {
+		c := []rune(t)
+		t = string(c[:punc+iAdj])
+	}
+
+	return t
+}

posts/render.go

@@ -3,6 +3,7 @@ package posts
 import (
 	"github.com/microcosm-cc/bluemonday"
 	"github.com/writeas/saturday"
+	"html"
 	"regexp"
 	"strings"
 	"unicode"
@@ -61,3 +62,9 @@ func ApplyBasicMarkdown(data []byte) string {
 
 	return outHTML
 }
+
+// StripHTMLWithoutEscaping strips HTML tags with bluemonday's StrictPolicy, then unescapes the HTML
+// entities added in by sanitizing the content.
+func StripHTMLWithoutEscaping(content string) string {
+	return html.UnescapeString(bluemonday.StrictPolicy().Sanitize(content))
+}

silobridge/silobridge.go

@@ -0,0 +1,29 @@
+package silobridge
+
+// fakeAPInstances contains a list of sites that we allow writers to mention
+// with the @handle@instance.tld syntax, plus the corresponding prefix to
+// insert between `https://instance.tld/` and `handle` (e.g.
+// https://medium.com/@handle)
+var fakeAPInstances = map[string]string{
+	"deviantart.com": "",
+	"facebook.com":   "",
+	"flickr.com":     "photos/",
+	"github.com":     "",
+	"instagram.com":  "",
+	"medium.com":     "@",
+	"reddit.com":     "user/",
+	"twitter.com":    "",
+	"wattpad.com":    "user/",
+	"youtube.com":    "user/",
+}
+
+// Profile returns the full profile URL for a fake ActivityPub instance, based
+// on the given handle and domain. If the domain isn't recognized, an empty
+// string is returned.
+func Profile(handle, domain string) string {
+	prefix, ok := fakeAPInstances[domain]
+	if !ok {
+		return ""
+	}
+	return "https://" + domain + "/" + prefix + handle
+}