Add HTML templates

These templates generate HTML documents that informs visitors and the Go toolchain about the location of the module's source and documentation page (on pkg.go.dev) Signed-off-by: Nicolas Paul <n@nc0.fr>
author: Nicolas Paul <n@nc0.fr> 2023-05-26 23:19:10 +0200
committer: Nicolas Paul <n@nc0.fr> 2023-05-26 23:19:27 +0200
commit: 9287bcd3b5fbefd260c0202ada4573d4a93961a1 (patch)
tree: 143a2c56b2c85f442fd3749bfff3116f813d63cd
parent: 39c37ae2178ba9fb69c4d51c773c27708729ce7b (diff)
2 files changed, 240 insertions, 0 deletions
diff --git a/templates.go b/templates.go
new file mode 100644
index 0000000..1024325
--- /dev/null
+++ b/templates.go
@@ -0,0 +1,82 @@
+package main
+
+import (
+	"fmt"
+	"html/template"
+	"io"
+)
+
+// HTML document templates
+var (
+	// indexTmpl is the HTML template for the root of the static site.
+	// It redirects to a site configured by the user.
+	//
+	// {{.Count}} corresponds to the timer—in seconds— before redirecting.
+	// {{.Redirect}} is the URL to redirect visitors to.
+	indexTmpl *template.Template = template.Must(
+		template.New("index").Parse(`<!DOCTYPE html>
+<meta charset="UTF-8">
+<meta http-equiv="refresh" content="{{.Count}}; url='{{.Redirect}}'">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<p>Nothing to see, redirecting <a href="{{.Redirect}}">here</a>.`))
+
+	// moduleTmpl is the HTML template for module-specific documents.
+	// They include information for the Go toolchain to find and download
+	// the module source code. It also redirects users to the module's
+	// documentation on pkg.go.dev.
+	//
+	// {{.Prefix}} is the module's prefix, a.k.a. import path,
+	// e.g. example.com/foo
+	// {{.Vcs}} is the version control system used in the codebase
+	// {{.Home}} is the repository's home.
+	// {{.Dir}} is a URL template to a page listing the files inside a package
+	// {{.File}} is a URL template listing the lines of a file
+	// {{.Doc}} is the URL of the module's documentation on pkg.go.dev
+	//
+	// Templates support a specific set of substitutions which are documented
+	// here: https://github.com/golang/gddo/wiki/Source-Code-Links
+	moduleTmpl *template.Template = template.Must(
+		template.New("module").Parse(`<!DOCTYPE html>
+<meta charset="UTF-8">
+<meta name="go-import" content="{{.Prefix}} {{.Vcs}} {{.Home}}">
+<meta name="go-source" content="{{.Prefix}} {{.Home}} {{.Dir}} {{.File}}">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<p>There is nothing to see, redirecting <a href="{{.Doc}}">here</a>.`))
+)
+
+// ExecIndex constructs an HTML document for the index of the generated site
+// in the given writer "w."
+// The document redirects visitor to the specified "url" after "count" seconds.
+func ExecIndex(w io.Writer, url string, count uint8) error {
+	return indexTmpl.Execute(w, struct {
+		Redirect string
+		Count    uint8
+	}{
+		Redirect: url,
+		Count:    count,
+	})
+}
+
+// ExecModule constructs an HTML document for a module indexed on the domain
+// in the given writer "w." The "prefix" corresponds to the import path of the
+// module, "vcs" to the version control system used — git, bazaar..., "home"
+// is the repository's home and "dir"/"file" are URL templates as documented
+// by GoDoc: https://github.com/golang/gddo/wiki/Source-Code-Links.
+func ExecModule(w io.Writer, prefix, vcs,
+	home, dir, file string) error {
+	return moduleTmpl.Execute(w, struct {
+		Prefix string
+		Vcs    string
+		Home   string
+		Dir    string
+		File   string
+		Doc    string
+	}{
+		Prefix: prefix,
+		Vcs:    vcs,
+		Home:   home,
+		Dir:    dir,
+		File:   file,
+		Doc:    fmt.Sprintf("https://pkg.go.dev/%s", prefix),
+	})
+}
diff --git a/templates_test.go b/templates_test.go
new file mode 100644
index 0000000..680651f
--- /dev/null
+++ b/templates_test.go
@@ -0,0 +1,158 @@
+package main
+
+import (
+	"bytes"
+	"io"
+	"testing"
+)
+
+func TestExecIndex(t *testing.T) {
+	type args struct {
+		url   string
+		count uint8
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    *bytes.Buffer
+		wantErr bool
+	}{
+		{
+			name: "valid url waiting 5 seconds",
+			args: args{
+				url:   "https://example.com",
+				count: 5,
+			},
+			want: bytes.NewBufferString(`<!DOCTYPE html>
+<meta charset="UTF-8">
+<meta http-equiv="refresh" content="5; url='https://example.com'">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<p>Nothing to see, redirecting <a href="https://example.com">here</a>.`),
+			wantErr: false,
+		},
+		{
+			name: "valid url waiting 0 second",
+			args: args{
+				url:   "https://example.com",
+				count: 0,
+			},
+			want: bytes.NewBufferString(`<!DOCTYPE html>
+<meta charset="UTF-8">
+<meta http-equiv="refresh" content="0; url='https://example.com'">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<p>Nothing to see, redirecting <a href="https://example.com">here</a>.`),
+			wantErr: false,
+		},
+		{
+			name: "not the same url",
+			args: args{
+				url:   "https://example.com",
+				count: 0,
+			},
+			want: bytes.NewBufferString(`<!DOCTYPE html>
+<meta charset="UTF-8">
+<meta http-equiv="refresh" content="0; url='https://example2.com'">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<p>Nothing to see, redirecting <a href="https://example.com">here</a>.`),
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var buf bytes.Buffer
+			err := ExecIndex(&buf, tt.args.url, tt.args.count)
+
+			if !tt.wantErr && err != nil {
+				t.Errorf("ExecIndex() error = %v", err)
+			}
+
+			if !tt.wantErr && !bytes.Equal(buf.Bytes(), tt.want.Bytes()) {
+				t.Errorf("ExecIndex() = %v, want %v", buf, tt.want)
+			}
+		})
+	}
+}
+
+func TestExecModule(t *testing.T) {
+	type args struct {
+		w      *io.Writer
+		prefix string
+		vcs    string
+		home   string
+		dir    string
+		file   string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    *bytes.Buffer
+		wantErr bool
+	}{
+		{
+			name: "module example.com/foo hosted on github",
+			args: args{
+				prefix: "example.com/foo",
+				vcs:    "git",
+				home:   "https://github.com/example/foo",
+				dir:    "https://github.com/example/foo/tree/master{/dir}",
+				file:   "https://github.com/example/foo/blob/master{/dir}/{file}#L{line}",
+			},
+			want: bytes.NewBufferString(`<!DOCTYPE html>
+<meta charset="UTF-8">
+<meta name="go-import" content="example.com/foo git https://github.com/example/foo">
+<meta name="go-source" content="example.com/foo https://github.com/example/foo https://github.com/example/foo/tree/master{/dir} https://github.com/example/foo/blob/master{/dir}/{file}#L{line}">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<p>There is nothing to see, redirecting <a href="https://pkg.go.dev/example.com/foo">here</a>.`),
+			wantErr: false,
+		},
+		{
+			name: "module example.com/foo hosted on gitlab",
+			args: args{
+				prefix: "example.com/foo",
+				vcs:    "git",
+				home:   "https://gitlab.com/example/foo",
+				dir:    "https://gitlab.com/example/foo/-/tree/master{/dir}",
+				file:   "https://gitlab.com/example/foo/-/blob/master{/dir}/{file}#L{line}",
+			},
+			want: bytes.NewBufferString(`<!DOCTYPE html>
+<meta charset="UTF-8">
+<meta name="go-import" content="example.com/foo git https://gitlab.com/example/foo">
+<meta name="go-source" content="example.com/foo https://gitlab.com/example/foo https://gitlab.com/example/foo/-/tree/master{/dir} https://gitlab.com/example/foo/-/blob/master{/dir}/{file}#L{line}">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<p>There is nothing to see, redirecting <a href="https://pkg.go.dev/example.com/foo">here</a>.`),
+			wantErr: false,
+		},
+		{
+			name: "module example.com/foo hosted on Source Hut with Mercurial",
+			args: args{
+				prefix: "example.com/foo",
+				vcs:    "hg",
+				home:   "https://hg.sr.ht/~example/foo",
+				dir:    "https://hg.sr.ht/~example/foo/tree/master{/dir}",
+				file:   "https://hg.sr.ht/~example/foo/browse/master{/dir}/{file}#{line}",
+			},
+			want: bytes.NewBufferString(`<!DOCTYPE html>
+<meta charset="UTF-8">
+<meta name="go-import" content="example.com/foo hg https://hg.sr.ht/~example/foo">
+<meta name="go-source" content="example.com/foo https://hg.sr.ht/~example/foo https://hg.sr.ht/~example/foo/tree/master{/dir} https://hg.sr.ht/~example/foo/browse/master{/dir}/{file}#{line}">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<p>There is nothing to see, redirecting <a href="https://pkg.go.dev/example.com/foo">here</a>.`),
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var buf bytes.Buffer
+			err := ExecModule(&buf, tt.args.prefix, tt.args.vcs, tt.args.home,
+				tt.args.dir, tt.args.file)
+
+			if !tt.wantErr && err != nil {
+				t.Errorf("ExecIndex() error = %v", err)
+			}
+
+			if !tt.wantErr && !bytes.Equal(buf.Bytes(), tt.want.Bytes()) {
+				t.Errorf("ExecIndex() = %v, want %v", buf, tt.want)
+			}
+		})
+	}
+}
author	Nicolas Paul <n@nc0.fr>	2023-05-26 23:19:10 +0200
committer	Nicolas Paul <n@nc0.fr>	2023-05-26 23:19:27 +0200
commit	9287bcd3b5fbefd260c0202ada4573d4a93961a1 (patch)
tree	143a2c56b2c85f442fd3749bfff3116f813d63cd
parent	39c37ae2178ba9fb69c4d51c773c27708729ce7b (diff)