| 1 | package check |
| 2 | |
| 3 | import ( |
| 4 | "net/url" |
| 5 | "path" |
| 6 | "regexp" |
| 7 | "strings" |
| 8 | "testing" |
| 9 | ) |
| 10 | |
| 11 | // parityLinks rewrites a document's asset links to the flat names the |
| 12 | // parity rig serves beside the page: a layout's ../../css/tokens.css, |
| 13 | // ../../css/themes/<theme>.css, ../../css/shell.css and ../../js/<file> |
| 14 | // become tokens.css, theme.css, shell.css and <file>, and the depth |
| 15 | // fixture's /tokens.css, /theme.css and /<file>.js the same. Only the |
| 16 | // stylesheet links and script tags are touched: an anchor in the body |
| 17 | // is the page's own, and stays. |
| 18 | // |
| 19 | // Its contract is the tree's own links. A path, relative or from the |
| 20 | // root, is flattened to its last segment, and a path with a /themes/ |
| 21 | // segment is the theme, whichever theme it names. A URL with a scheme |
| 22 | // or a host (https://fonts.example/x.css, //cdn.example/y.js) is left |
| 23 | // as it is: the rig has nothing to serve for it, and a layout that |
| 24 | // gains one wants it fetched from where it points. Two files that |
| 25 | // share a base name under different directories would collide; the |
| 26 | // tree has none. |
| 27 | func parityLinks(doc string) string { |
| 28 | return assetLinks(doc, "") |
| 29 | } |
| 30 | |
| 31 | // assetLinks is parityLinks with the flat names under dir: "" for the |
| 32 | // names beside the page, "/" for the root paths the sizing mux serves |
| 33 | // (shellPage), so a page served below the root still finds them. |
| 34 | func assetLinks(doc, dir string) string { |
| 35 | return assetLink.ReplaceAllStringFunc(doc, func(tag string) string { |
| 36 | return assetURL.ReplaceAllStringFunc(tag, func(attr string) string { |
| 37 | m := assetURL.FindStringSubmatch(attr) |
| 38 | if u, err := url.Parse(m[2]); err != nil || u.Scheme != "" || u.Host != "" { |
| 39 | return attr |
| 40 | } |
| 41 | name := path.Base(m[2]) |
| 42 | if strings.Contains(m[2], "/themes/") { |
| 43 | name = "theme.css" |
| 44 | } |
| 45 | return m[1] + dir + name + `"` |
| 46 | }) |
| 47 | }) |
| 48 | } |
| 49 | |
| 50 | // assetURL is the href or src attribute inside one asset link. |
| 51 | var assetURL = regexp.MustCompile(`((?:href|src)=")([^"]*)"`) |
| 52 | |
| 53 | // TestParityLinksAreRewritten holds parityLinks to one layout document: |
| 54 | // every stylesheet and script it links comes out as a flat name beside |
| 55 | // the page, the theme under whichever name the layout linked it as |
| 56 | // theme.css, the body's own links untouched, and nothing else in the |
| 57 | // document moved. A rewrite that missed a link would leave the parity |
| 58 | // rig serving a 404 the harness reports, which is a failure for the |
| 59 | // wrong reason; one that touched an anchor would compare a page the |
| 60 | // layout never wrote. |
| 61 | func TestParityLinksAreRewritten(t *testing.T) { |
| 62 | m := manifest(t) |
| 63 | state, ok := m.Default("layout-sidebar") |
| 64 | if !ok || state == "" { |
| 65 | t.Fatal("examples.json names no default state for layout-sidebar") |
| 66 | } |
| 67 | doc := defaultMarkup(t, "layout-sidebar") |
| 68 | for _, want := range []string{`href="../../css/tokens.css"`, `href="../../css/themes/day.css"`, `href="../../css/shell.css"`, `src="../../js/shell.js"`, `href="/"`} { |
| 69 | if !strings.Contains(doc, want) { |
| 70 | t.Fatalf("layout-sidebar/%s no longer links %s; the control has nothing to rewrite", state, want) |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | got := parityLinks(doc) |
| 75 | for _, want := range []string{ |
| 76 | `<link rel="stylesheet" href="tokens.css">`, |
| 77 | `<link rel="stylesheet" href="theme.css">`, |
| 78 | `<link rel="stylesheet" href="shell.css">`, |
| 79 | `<script defer src="fiesta.js"></script>`, |
| 80 | `<script defer blocking="render" src="shell.js"></script>`, |
| 81 | } { |
| 82 | if !strings.Contains(got, want) { |
| 83 | t.Errorf("the rewritten layout does not link %s", want) |
| 84 | } |
| 85 | } |
| 86 | if strings.Contains(got, "../../") { |
| 87 | t.Errorf("a relative link survived the rewrite:\n%s", linkLines(got)) |
| 88 | } |
| 89 | if n := strings.Count(got, `href="theme.css"`); n != 1 { |
| 90 | t.Errorf("the rewritten layout links theme.css %d times, want once", n) |
| 91 | } |
| 92 | if strings.Count(got, `href="/"`) != strings.Count(doc, `href="/"`) { |
| 93 | t.Errorf("the rewrite touched the body's own links: %d href=\"/\" before, %d after", strings.Count(doc, `href="/"`), strings.Count(got, `href="/"`)) |
| 94 | } |
| 95 | // The link tags are the only lines that change: strip every asset |
| 96 | // link from both and what is left is byte for byte the same. |
| 97 | strip := func(s string) string { return assetLink.ReplaceAllString(s, "") } |
| 98 | if strip(got) != strip(doc) { |
| 99 | t.Errorf("the rewrite changed more than the asset links") |
| 100 | } |
| 101 | if strip(doc) == doc { |
| 102 | t.Fatal("the control stripped nothing; assetLink matches no link in the layout") |
| 103 | } |
| 104 | |
| 105 | // The limits: a URL with a scheme or a host is not the rig's to |
| 106 | // serve and stays as written, beside the tree's own links, which |
| 107 | // still flatten; and the depth fixture's root paths flatten too. |
| 108 | const foreign = `<link rel="stylesheet" href="https://fonts.example/face.css"><script defer src="//cdn.example/lib.js"></script>` |
| 109 | mixed := `<head>` + foreign + `<link rel="stylesheet" href="../../css/themes/signal.css"><script defer src="/fiesta.js"></script></head>` |
| 110 | if got, want := parityLinks(mixed), `<head>`+foreign+`<link rel="stylesheet" href="theme.css"><script defer src="fiesta.js"></script></head>`; got != want { |
| 111 | t.Errorf("the rewrite of foreign and root links:\n got %s\n want %s", got, want) |
| 112 | } |
| 113 | // Under a directory, for the shell drives: the same names from the |
| 114 | // root, the foreign URLs still untouched. |
| 115 | if got, want := assetLinks(mixed, "/"), `<head>`+foreign+`<link rel="stylesheet" href="/theme.css"><script defer src="/fiesta.js"></script></head>`; got != want { |
| 116 | t.Errorf("the rewrite under /:\n got %s\n want %s", got, want) |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | // assetLink is a stylesheet link or a script tag, the tags parityLinks |
| 121 | // rewrites; the test above uses it to prove nothing else changed. |
| 122 | var assetLink = regexp.MustCompile(`<link[^>]*rel="stylesheet"[^>]*>|<script[^>]*src="[^"]*"[^>]*></script>`) |
| 123 | |
| 124 | // linkLines is the asset links of a document, one per line, for a |
| 125 | // failure message. |
| 126 | func linkLines(doc string) string { |
| 127 | return strings.Join(assetLink.FindAllString(doc, -1), "\n") |
| 128 | } |
| 129 | |
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