ampproject · xiexr151e · Jan 31, 2020 · Feb 4, 2020 · Apr 27, 2020 · Jul 10, 2020
diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md
@@ -0,0 +1 @@
+See https://github.com/ampproject/meta/blob/master/CODE_OF_CONDUCT.md
diff --git a/transformer/transformer.go b/transformer/transformer.go
@@ -30,8 +30,8 @@ import (
 	rpb "github.com/ampproject/amppackager/transformer/request"
 	"github.com/ampproject/amppackager/transformer/transformers"
 	"github.com/pkg/errors"
-	"golang.org/x/net/html/atom"
 	"golang.org/x/net/html"
+	"golang.org/x/net/html/atom"
 )
 
 // Transformer functions must be added here in order to be passed in from
@@ -44,6 +44,7 @@ var transformerFunctionMap = map[string]func(*transformers.Context) error{
 	"absoluteurl":           transformers.AbsoluteURL,
 	"ampboilerplate":        transformers.AMPBoilerplate,
 	"ampruntimecss":         transformers.AMPRuntimeCSS,
+	"ampruntimejs":          transformers.AMPRuntimeJS,
 	"linktag":               transformers.LinkTag,
 	"nodecleanup":           transformers.NodeCleanup,
 	"preloadimage":          transformers.PreloadImage,
@@ -72,6 +73,7 @@ var configMap = map[rpb.Request_TransformersConfig][]func(*transformers.Context)
 		transformers.AMPRuntimeCSS,
 		transformers.TransformedIdentifier,
 		transformers.URLRewrite,
+		transformers.AMPRuntimeJS,
 		transformers.PreloadImage,
 		// ReorderHead should run after all transformers that modify the
 		// <head>, as they may do so without preserving the proper order.
@@ -90,7 +92,6 @@ var configMap = map[rpb.Request_TransformersConfig][]func(*transformers.Context)
 // from an unnecessary number of fetches.
 const maxPreloads = 20
 
-
 // Override for tests.
 var runTransformers = func(c *transformers.Context, fns []func(*transformers.Context) error) error {
 	// Invoke the configured transformers
@@ -224,11 +225,11 @@ func extractPreloads(dom *amphtml.DOM) []*rpb.Metadata_Preload {
 // amp-script without an explicit max-age. This is 1 day, to parallel the
 // security precautions put in place around service workers:
 // https://dev.chromium.org/Home/chromium-security/security-faq/service-worker-security-faq#TOC-Do-Service-Workers-live-forever-
-const defaultMaxAgeSeconds int32 = 86400  // number of seconds in a day
+const defaultMaxAgeSeconds int32 = 86400 // number of seconds in a day
 
 // maxMaxAgeSeconds is the max duration of an SXG, per
 // https://wicg.github.io/webpackage/draft-yasskin-http-origin-signed-responses.html#signature-validity.
-const maxMaxAgeSeconds int32 = 7*86400
+const maxMaxAgeSeconds int32 = 7 * 86400
 
 // computeMaxAgeSeconds returns the suggested max-age based on the presence of
 // any inline <amp-script> tags on the page; callers should min() the return
@@ -317,7 +318,7 @@ func Process(r *rpb.Request) (string, *rpb.Metadata, error) {
 		return "", nil, err
 	}
 	metadata := rpb.Metadata{
-		Preloads: extractPreloads(context.DOM),
+		Preloads:   extractPreloads(context.DOM),
 		MaxAgeSecs: computeMaxAgeSeconds(context.DOM),
 	}
 	return o.String(), &metadata, nil

diff --git a/transformer/transformer_test.go b/transformer/transformer_test.go
@@ -27,7 +27,7 @@ func TestProcess(t *testing.T) {
 		config      rpb.Request_TransformersConfig
 		expectedLen int
 	}{
-		{rpb.Request_DEFAULT, 13},
+		{rpb.Request_DEFAULT, 14},
 		{rpb.Request_NONE, 0},
 		{rpb.Request_VALIDATION, 1},
 		{rpb.Request_CUSTOM, 0},

diff --git a/transformer/transformers/ampruntimejs.go b/transformer/transformers/ampruntimejs.go
@@ -0,0 +1,38 @@
+package transformers
+
+import (
+	"net/url"
+	"strings"
+
+	"github.com/ampproject/amppackager/transformer/internal/amphtml"
+	"github.com/ampproject/amppackager/transformer/internal/htmlnode"
+	"golang.org/x/net/html"
+	"golang.org/x/net/html/atom"
+)
+
+// AMPRuntimeJS rewrites the value of src in script nodes, where applicable.
+// If the value is of the form "*.js", replace it with "*.js?f=sxg".
+func AMPRuntimeJS(e *Context) error {
+	for n := e.DOM.HeadNode.FirstChild; n != nil; n = n.NextSibling {
+		if n.Type == html.ElementNode && n.DataAtom == atom.Script {
+			src, ok := htmlnode.FindAttribute(n, "", "src")
+			if ok && strings.HasPrefix(src.Val, amphtml.AMPCacheRootURL) {
+				u, uerr := url.Parse(src.Val)
+				if uerr != nil {
+					continue
+				}
+				query, queryerr := url.ParseQuery(u.RawQuery)
+				if queryerr != nil {
+					continue
+				}
+				path := u.Path
+				if strings.HasSuffix(path, ".js") {
+					query.Set("f", "sxg")
+					u.RawQuery = query.Encode()
+					src.Val = u.String()
+				}
+			}
+		}
+	}
+	return nil
+}
diff --git a/transformer/transformers/ampruntimejs_test.go b/transformer/transformers/ampruntimejs_test.go
@@ -0,0 +1,100 @@
+package transformers_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/ampproject/amppackager/transformer/internal/amphtml"
+	tt "github.com/ampproject/amppackager/transformer/internal/testing"
+	"github.com/ampproject/amppackager/transformer/transformers"
+	"golang.org/x/net/html"
+)
+
+func TestAmpRuntimeJS(t *testing.T) {
+	tcs := []tt.TestCase{
+		{
+			Desc:     "no script node",
+			Input:    "<head></head><body></body>",
+			Expected: "<head></head><body></body>",
+		},
+		{
+			Desc:     "no prefix",
+			Input:    "<head><script src=main.js/></head>",
+			Expected: "<head><script src=main.js/></head>",
+		},
+		{
+			Desc:     "no suffix",
+			Input:    `<head><script src="https://cdn.ampproject.org"/></head>`,
+			Expected: `<head><script src="https://cdn.ampproject.org"/></head>`,
+		},
+		{
+			Desc:     "transformation",
+			Input:    `<head><script async src="https://cdn.ampproject.org/v0.js"></script></head>`,
+			Expected: `<head><script async src="https://cdn.ampproject.org/v0.js?f=sxg"></script></head>`,
+		},
+		{
+			Desc:     "transform on two scripts",
+			Input:    `<head><script async src="https://cdn.ampproject.org/foo.js"></script><script async src="https://cdn.ampproject.org/bar.js"></script></head>`,
+			Expected: `<head><script async src="https://cdn.ampproject.org/foo.js?f=sxg"></script><script async src="https://cdn.ampproject.org/bar.js?f=sxg"></script></head>`,
+		},
+		{
+			Desc:     "skip one, transform one",
+			Input:    `<head><script async src="https://cdn.ampproject.org/"></script><script async src="https://cdn.ampproject.org/bar.js"></script></head>`,
+			Expected: `<head><script async src="https://cdn.ampproject.org/"></script><script async src="https://cdn.ampproject.org/bar.js?f=sxg"></script></head>`,
+		},
+		{
+			Desc:     "additional params exist",
+			Input:    `<head><script async src="https://cdn.ampproject.org/v0.js?optin=beta"></script></head>`,
+			Expected: `<head><script async src="https://cdn.ampproject.org/v0.js?f=sxg&optin=beta"></script></head>`,
+		},
+		{
+			Desc:     "existing f param",
+			Input:    `<head><script async src="https://cdn.ampproject.org/v0.js?f=foo"></script></head>`,
+			Expected: `<head><script async src="https://cdn.ampproject.org/v0.js?f=sxg"></script></head>`,
+		},
+		{
+			Desc:     "url escape parsing bug in query param",
+			Input:    `<head><script async src="https://cdn.ampproject.org/v0.js?x=%"></script></head>`,
+			Expected: `<head><script async src="https://cdn.ampproject.org/v0.js?x=%"></script></head>`,
+		},
+		{
+			Desc:     "url escape parsing bug",
+			Input:    `<head><script async src="https://cdn.ampproject.org/v0.js%%"></script></head>`,
+			Expected: `<head><script async src="https://cdn.ampproject.org/v0.js%%"></script></head>`,
+		},
+	}
+
+	for _, tc := range tcs {
+		inputDoc, err := html.Parse(strings.NewReader(tc.Input))
+		if err != nil {
+			t.Errorf("%s: html.Parse failed %q", tc.Input, err)
+			continue
+		}
+		inputDOM, err := amphtml.NewDOM(inputDoc)
+		if err != nil {
+			t.Errorf("%s\namphtml.NewDOM for %s failed %q", tc.Desc, tc.Input, err)
+			continue
+		}
+		transformers.AMPRuntimeJS(&transformers.Context{DOM: inputDOM})
+		var input strings.Builder
+		if err := html.Render(&input, inputDoc); err != nil {
+			t.Errorf("%s: html.Render failed %q", tc.Input, err)
+			continue
+		}
+
+		expectedDoc, err := html.Parse(strings.NewReader(tc.Expected))
+		if err != nil {
+			t.Errorf("%s: html.Parse failed %q", tc.Expected, err)
+			continue
+		}
+		var expected strings.Builder
+		err = html.Render(&expected, expectedDoc)
+		if err != nil {
+			t.Errorf("%s: html.Render failed %q", tc.Expected, err)
+			continue
+		}
+		if input.String() != expected.String() {
+			t.Errorf("%s: Transform=\n%q\nwant=\n%q", tc.Desc, &input, &expected)
+		}
+	}
+}