authhandler: Update TestTokenExchange_Success test

`TestTokenExchange_Success` now runs in two parts; one check is the
exact same check as was present before this commit, while the second
test passes a "duration" AuthCodeOption to TokenSource() and checks that
the same duration is returned by the test http server.

authhandler/authhandler_test.go

@@ -15,22 +15,17 @@ import (
 )
 
 func TestTokenExchange_Success(t *testing.T) {
-	authhandler := func(authCodeURL string) (string, string, error) {
-		if authCodeURL == "testAuthCodeURL?client_id=testClientID&response_type=code&scope=pubsub&state=testState" {
-			return "testCode", "testState", nil
-		}
-		return "", "", fmt.Errorf("invalid authCodeURL: %q", authCodeURL)
-	}
-
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		r.ParseForm()
 		if r.Form.Get("code") == "testCode" {
 			w.Header().Set("Content-Type", "application/json")
+
 			w.Write([]byte(`{
 				"access_token": "90d64460d14870c08c81352a05dedd3465940a7c",
 				"scope": "pubsub",
 				"token_type": "bearer",
-				"expires_in": 3600
+				"expires_in": 3600,
+				"duration": "permanent"
 			}`))
 		}
 	}))
@@ -45,26 +40,59 @@ func TestTokenExchange_Success(t *testing.T) {
 		},
 	}
 
-	tok, err := TokenSource(context.Background(), conf, "testState", authhandler).Token()
-	if err != nil {
-		t.Fatal(err)
-	}
-	if !tok.Valid() {
-		t.Errorf("got invalid token: %v", tok)
-	}
-	if got, want := tok.AccessToken, "90d64460d14870c08c81352a05dedd3465940a7c"; got != want {
-		t.Errorf("access token = %q; want %q", got, want)
-	}
-	if got, want := tok.TokenType, "bearer"; got != want {
-		t.Errorf("token type = %q; want %q", got, want)
-	}
-	if got := tok.Expiry.IsZero(); got {
-		t.Errorf("token expiry is zero = %v, want false", got)
-	}
-	scope := tok.Extra("scope")
-	if got, want := scope, "pubsub"; got != want {
-		t.Errorf("scope = %q; want %q", got, want)
+	testExchange := func(authHandler AuthorizationHandler, opts ...oauth2.AuthCodeOption) {
+		tok, err := TokenSource(context.Background(), conf, "testState", authHandler, opts...).Token()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !tok.Valid() {
+			t.Errorf("got invalid token: %v", tok)
+		}
+		if got, want := tok.AccessToken, "90d64460d14870c08c81352a05dedd3465940a7c"; got != want {
+			t.Errorf("access token = %q; want %q", got, want)
+		}
+		if got, want := tok.TokenType, "bearer"; got != want {
+			t.Errorf("token type = %q; want %q", got, want)
+		}
+		if got := tok.Expiry.IsZero(); got {
+			t.Errorf("token expiry is zero = %v, want false", got)
+		}
+		scope := tok.Extra("scope")
+		if got, want := scope, "pubsub"; got != want {
+			t.Errorf("scope = %q; want %q", got, want)
+		}
+
+		if opts != nil && len(opts) > 0 {
+			duration := tok.Extra("duration")
+			if got, want := duration, "permanent"; got != want {
+				t.Errorf("duration = %q; want %q", got, want)
+			}
+		}
 	}
+
+	t.Run("test no extra options", func(t *testing.T) {
+		authhandler := func(authCodeURL string) (string, string, error) {
+			if authCodeURL == "testAuthCodeURL?client_id=testClientID&response_type=code&scope=pubsub&state=testState" {
+				return "testCode", "testState", nil
+			}
+			return "", "", fmt.Errorf("invalid authCodeURL: %q", authCodeURL)
+		}
+
+		testExchange(authhandler)
+	})
+
+	t.Run("test with AuthCodeOptions", func(t *testing.T) {
+		authhandler := func(authCodeURL string) (string, string, error) {
+			if authCodeURL == "testAuthCodeURL?client_id=testClientID&duration=permanent&response_type=code&scope=pubsub&state=testState" {
+				return "testCode", "testState", nil
+			}
+			return "", "", fmt.Errorf("invalid authCodeURL: %q", authCodeURL)
+		}
+
+		testAuthOpt := oauth2.SetAuthURLParam("duration", "permanent")
+
+		testExchange(authhandler, testAuthOpt)
+	})
 }
 
 func TestTokenExchange_StateMismatch(t *testing.T) {