retain query string from original request

When resolving a go link, combine the query string parameters from the
request and long URL.

Updates #77

Signed-off-by: Will Norris <[email protected]>

Author: willnorris

golink.go

@@ -397,7 +397,8 @@ func serveGo(w http.ResponseWriter, r *http.Request) {
 	stats.mu.Unlock()
 
 	login, _ := currentUser(r)
-	target, err := expandLink(link.Long, expandEnv{Now: time.Now().UTC(), Path: remainder, user: login})
+	env := expandEnv{Now: time.Now().UTC(), Path: remainder, user: login, query: r.URL.Query()}
+	target, err := expandLink(link.Long, env)
 	if err != nil {
 		log.Printf("expanding %q: %v", link.Long, err)
 		if errors.Is(err, errNoUser) {
@@ -475,6 +476,9 @@ type expandEnv struct {
 	// user is the current user, if any.
 	// For example, "[email protected]" or "foo@github".
 	user string
+
+	// query is the query parameters from the original request.
+	query url.Values
 }
 
 var errNoUser = errors.New("no user")
@@ -521,6 +525,17 @@ func expandLink(long string, env expandEnv) (*url.URL, error) {
 		return nil, err
 	}
 
+	// add query parameters from original request
+	if len(env.query) > 0 {
+		query := u.Query()
+		for key, values := range env.query {
+			for _, v := range values {
+				query.Add(key, v)
+			}
+		}
+		u.RawQuery = query.Encode()
+	}
+
 	return u, nil
 }
 

golink_test.go

@@ -59,15 +59,15 @@ func TestServeGo(t *testing.T) {
 		},
 		{
 			name:       "simple link with query",
-			link:       "/who?q",
+			link:       "/who?q=1",
 			wantStatus: http.StatusFound,
-			wantLink:   "http://who/", // TODO: eventually http://who/?q
+			wantLink:   "http://who/?q=1",
 		},
 		{
 			name:       "simple link with path and query",
-			link:       "/who/p?q",
+			link:       "/who/p?q=1",
 			wantStatus: http.StatusFound,
-			wantLink:   "http://who/p", // TODO: eventually http://who/p?q
+			wantLink:   "http://who/p?q=1",
 		},
 		{
 			name:       "user link",
@@ -282,6 +282,7 @@ func TestExpandLink(t *testing.T) {
 		long      string    // long URL for golink
 		now       time.Time // current time
 		user      string    // current user resolving link
+		query     string    // query string
 		remainder string    // remainder of URL path after golink name
 		wantErr   bool      // whether we expect an error
 		want      string    // expected redirect URL
@@ -372,11 +373,38 @@ func TestExpandLink(t *testing.T) {
 			remainder: "a",
 			want:      "/rel/a",
 		},
-
+		{
+			name:  "query-string",
+			long:  `/rel`,
+			query: "a=b",
+			want:  "/rel?a=b",
+		},
+		{
+			name:      "path-and-query-string",
+			long:      `/rel`,
+			remainder: "path",
+			query:     "a=b",
+			want:      "/rel/path?a=b",
+		},
+		{
+			name:  "combine-query-string",
+			long:  `/rel?a=1`,
+			query: "a=2&b=2",
+			want:  "/rel?a=1&a=2&b=2",
+		},
+		{
+			name:      "template-and-combined-query-string",
+			long:      `/rel{{with .Path}}/{{.}}{{end}}?a=1`,
+			remainder: "path",
+			query:     "b=2",
+			want:      "/rel/path?a=1&b=2",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			link, err := expandLink(tt.long, expandEnv{Now: tt.now, Path: tt.remainder, user: tt.user})
+			query, _ := url.ParseQuery(tt.query)
+			env := expandEnv{Now: tt.now, Path: tt.remainder, user: tt.user, query: query}
+			link, err := expandLink(tt.long, env)
 			if (err != nil) != tt.wantErr {
 				t.Fatalf("expandLink(%q) returned error %v; want %v", tt.long, err, tt.wantErr)
 			}