Merge branch 'hotfix/0.5.1'

Author: infeo

src/main/java/io/github/coffeelibs/tinyoauth2client/AuthFlow.java

@@ -197,9 +197,12 @@ URI buildAuthUri(URI redirectEndpoint, String csrfToken, Set<String> scopes) {
 				"state", csrfToken, //
 				"code_challenge", pkce.getChallenge(), //
 				"code_challenge_method", PKCE.METHOD, //
-				"redirect_uri", redirectEndpoint.toASCIIString(), //
-				"scope", String.join(" ", scopes)
+				"redirect_uri", redirectEndpoint.toASCIIString()
 		));
+
+		if(scopes.size() > 0) {
+			queryString += "&" + URIUtil.buildQueryString(Map.of("scope" ,String.join(" ", scopes)));
+		}
 		return URI.create(authEndpoint.getScheme() + "://" + authEndpoint.getRawAuthority() + authEndpoint.getRawPath() + "?" + queryString);
 	}
 

src/test/java/io/github/coffeelibs/tinyoauth2client/AuthFlowTest.java

@@ -180,7 +180,7 @@ public void testBuildAuthUri(URI authEndpoint, URI redirectEndpoint, String csrf
 
 	public static Stream<Arguments> testBuildAuthUri() {
 		return Stream.of( //
-				Arguments.of(URI.create("https://login.example.com/"), URI.create("http://127.0.0.1/callback"), "token", Set.of(), URI.create("https://login.example.com/?state=token&scope&code_challenge=C0D3Ch4ll3ng3&response_type=code&client_id=my-client&code_challenge_method=S256&redirect_uri=http%3A%2F%2F127.0.0.1%2Fcallback")), //
+				Arguments.of(URI.create("https://login.example.com/"), URI.create("http://127.0.0.1/callback"), "token", Set.of(), URI.create("https://login.example.com/?state=token&code_challenge=C0D3Ch4ll3ng3&response_type=code&client_id=my-client&code_challenge_method=S256&redirect_uri=http%3A%2F%2F127.0.0.1%2Fcallback")), //
 				Arguments.of(URI.create("https://login.example.com/?foo=bar"), URI.create("http://127.0.0.1/callback"), "token", Set.of(""), URI.create("https://login.example.com/?state=token&scope&code_challenge=C0D3Ch4ll3ng3&response_type=code&client_id=my-client&code_challenge_method=S256&redirect_uri=http%3A%2F%2F127.0.0.1%2Fcallback&foo=bar")), //
 				Arguments.of(URI.create("https://login.example.com/"), URI.create("http://127.0.0.1/callback"), "t0k3n", Set.of("offline_access"), URI.create("https://login.example.com/?state=t0k3n&scope=offline_access&code_challenge=C0D3Ch4ll3ng3&response_type=code&client_id=my-client&code_challenge_method=S256&redirect_uri=http%3A%2F%2F127.0.0.1%2Fcallback")), //
 				Arguments.of(URI.create("https://login.example.com/?foo=bar"), URI.create("http://127.0.0.1/callback"), "token", Set.of("offline_access"), URI.create("https://login.example.com/?state=token&scope=offline_access&code_challenge=C0D3Ch4ll3ng3&response_type=code&client_id=my-client&code_challenge_method=S256&redirect_uri=http%3A%2F%2F127.0.0.1%2Fcallback&foo=bar")), //