fix font asset inlining

lucas-gaitzsch · Nov 14, 2023 · ca1b115 · ca1b115
1 parent 21f2a9a
commit ca1b115
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Showing 2 changed files with 21 additions and 9 deletions.
diff --git a/utils/html-css.go b/utils/html-css.go
@@ -3,7 +3,7 @@ package utils
 import (
 	"context"
 	"encoding/base64"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"regexp"
 	"strings"
@@ -42,7 +42,7 @@ func MergeCss(css ...*string) *string {
 	return &mergedCss
 }
 
-var urlReferenceRegex = regexp.MustCompile(` (src|href)="([^"]+)"`)
+var urlReferenceRegex = regexp.MustCompile(`( src="| href="|src: *url\(")([^"]+)("\)|")`)
 
 type HttpClientExecuter interface {
     Do(req *http.Request) (*http.Response, error)
@@ -65,8 +65,9 @@ func RequestAndInlineAllHtmlResources(ctx context.Context, htmlPtr *string, base
 func requestAndReturnBase64IfPossible(ctx context.Context, htmlAttribute string, baseUrl string, logger *zerolog.Logger) string {
 
 	groups := urlReferenceRegex.FindAllStringSubmatch(htmlAttribute, 2)
-	attribute := groups[0][1]
+	prefix := groups[0][1]
 	src := groups[0][2]
+	suffix := groups[0][3]
 
 	if baseUrl != "" && !strings.HasPrefix(src, "http") {
 		src = baseUrl + src
@@ -90,7 +91,7 @@ func requestAndReturnBase64IfPossible(ctx context.Context, htmlAttribute string,
 	}
 	defer response.Body.Close()
 
-	bytes, err := ioutil.ReadAll(response.Body)
+	bytes, err := io.ReadAll(response.Body)
 	if err != nil {
 		logger.Info().Str("resourceUrl", src).Err(err).Msg("cant fetch resource: cant read from response body")
 		return htmlAttribute
@@ -101,5 +102,12 @@ func requestAndReturnBase64IfPossible(ctx context.Context, htmlAttribute string,
 	mimeType := http.DetectContentType(bytes)
 	base64 := base64.StdEncoding.EncodeToString(bytes)
 
-	return " " + attribute + "=\"data:" + mimeType + ";base64," + base64 + "\""
+	isCssSrcUrl := strings.HasSuffix(prefix, `url("`)
+
+	if (isCssSrcUrl) {
+		prefix = strings.TrimRight(prefix,`"`)
+		suffix = strings.TrimLeft(suffix,`"`)
+	}
+
+	return prefix + "data:" + mimeType + ";base64," + base64 + suffix
 }
diff --git a/utils/html-css_test.go b/utils/html-css_test.go
@@ -74,7 +74,7 @@ func (c *HttpClientMock) Do(req *http.Request) (*http.Response, error) {
 }
 
 func TestRequestAndInlineAllHtmlResources(t *testing.T) {
-	inputHtml := "<body>Hello World <img src=\"http://my-image.org/test1.png\"/> <img src=\"test2.png\"/> </body>"
+	inputHtml := "<head><style>@font-face{ src:  url(\"http://my-font.org/font.eot\"); }</style></head> <body>Hello World <img src=\"http://my-image.org/test1.png\"/> <img src=\"test2.png\"/> </body>"
 
 	httpClientMock := &HttpClientMock{}
 	ctx := context.WithValue(context.Background(), "httpClient", httpClientMock)
@@ -85,15 +85,19 @@ func TestRequestAndInlineAllHtmlResources(t *testing.T) {
 		t.Fatal("Result should not be nil")
 	}
 
-	if httpClientMock.RequestedResources[0] != "http://my-image.org/test1.png" {
+	if httpClientMock.RequestedResources[0] != "http://my-font.org/font.eot" {
+		t.Fatal("Font was not requested")
+	}
+
+	if httpClientMock.RequestedResources[1] != "http://my-image.org/test1.png" {
 		t.Fatal("First image was not requested")
 	}
 
-	if httpClientMock.RequestedResources[1] != "http://localhost:1234/test2.png" {
+	if httpClientMock.RequestedResources[2] != "http://localhost:1234/test2.png" {
 		t.Fatal("Second image was not requested")
 	}
 
-	expectedHtml := "<body>Hello World <img src=\"data:text/plain; charset=utf-8;base64,Zm9v\"/> <img src=\"data:text/plain; charset=utf-8;base64,Zm9v\"/> </body>"
+	expectedHtml := "<head><style>@font-face{ src:  url(data:text/plain; charset=utf-8;base64,Zm9v); }</style></head> <body>Hello World <img src=\"data:text/plain; charset=utf-8;base64,Zm9v\"/> <img src=\"data:text/plain; charset=utf-8;base64,Zm9v\"/> </body>"
 
 	if *outputPtr != expectedHtml {
 		t.Fatalf("Result was not expected: %s != %s", *outputPtr, expectedHtml)