fix: push '.' instead of '' when navigating (#12991) (#13018)

The API for Location::getPath/getPathWithQueryParameters was changed in V15 to return "" instead of "." for the base URL. However, it seems to not have been taken into account that FF / Safari do not navigate to base when passing the empty string for URL to the history methods (and this ticket, which seems to have observed that this workaround was necessary, was closed without action). This commit moves the workaround to its own method in History.

Fixes #5113

Co-authored-by: Johannes Eriksson <joheriks@vaadin.com>

Author: vaadin-bot

flow-server/src/main/java/com/vaadin/flow/component/page/History.java

@@ -182,8 +182,8 @@ public void pushState(JsonValue state, String location) {
      *            to only change the JSON state
      */
     public void pushState(JsonValue state, Location location) {
-        final String pathWithQueryParameters = Optional.ofNullable(location)
-                .map(Location::getPathWithQueryParameters).orElse(null);
+        final String pathWithQueryParameters = getPathWithQueryParameters(
+                location);
         // Second parameter is title which is currently ignored according to
         // https://developer.mozilla.org/en-US/docs/Web/API/History_API
         ui.getPage().executeJs(
@@ -221,8 +221,8 @@ public void replaceState(JsonValue state, String location) {
      *            to only change the JSON state
      */
     public void replaceState(JsonValue state, Location location) {
-        final String pathWithQueryParameters = Optional.ofNullable(location)
-                .map(Location::getPathWithQueryParameters).orElse(null);
+        final String pathWithQueryParameters = getPathWithQueryParameters(
+                location);
         // Second parameter is title which is currently ignored according to
         // https://developer.mozilla.org/en-US/docs/Web/API/History_API
         ui.getPage().executeJs(
@@ -297,4 +297,13 @@ public void forward() {
     public void go(int steps) {
         ui.getPage().executeJs("history.go($0)", steps);
     }
+
+    private String getPathWithQueryParameters(Location location) {
+        // In the Location API, getPath() returning "" means document base URL.
+        // On FF and Safari, passing '' for the URL parameter does not update
+        // URL to the base, so we replace '' with '.' here.
+        return Optional.ofNullable(location)
+                .map(Location::getPathWithQueryParameters)
+                .map(path -> path.isEmpty() ? "." : path).orElse(null);
+    }
 }

flow-server/src/test/java/com/vaadin/flow/component/page/HistoryTest.java

@@ -150,4 +150,14 @@ public void replaceState_locationWithQueryParametersAndFragment_QueryParametersA
                 page.parameters[1]);
     }
 
+    @Test // #11628
+    public void replaceState_locationEmpty_pushesPeriod() {
+        history.replaceState(null, "");
+        Assert.assertEquals("push state JS not included",
+                "setTimeout(() => window.history.replaceState($0, '', $1))",
+                page.expression);
+        Assert.assertEquals(null, page.parameters[0]);
+        Assert.assertEquals("location should be '.'", ".", page.parameters[1]);
+    }
+
 }