internal/api: centralize pagination and trimming logic

- All handlers returning lists will utilize the paginate helper.
- Path trimming logic has also been modularized within a helper.

Change-Id: I5c99ae8264ea76587137e29524ad19795652e43b
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/758642
Auto-Submit: Ethan Lee <ethanalee@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
kokoro-CI: kokoro <noreply+kokoro@google.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/internal/api/api_test.go b/internal/api/api_test.go
index 0bc409c5..9930e3c9 100644
--- a/internal/api/api_test.go
+++ b/internal/api/api_test.go
@@ -399,12 +399,30 @@ func TestServeModulePackages(t *testing.T) {
 		url        string
 		wantStatus int
 		wantCount  int
+		wantTotal  int
+		wantToken  string
 	}{
 		{
 			name:       "all packages",
 			url:        "/v1/packages/example.com?version=v1.0.0",
 			wantStatus: http.StatusOK,
 			wantCount:  2,
+			wantTotal:  2,
+		},
+		{
+			name:       "limit and token",
+			url:        "/v1/packages/example.com?version=v1.0.0&limit=1",
+			wantStatus: http.StatusOK,
+			wantCount:  1,
+			wantTotal:  2,
+			wantToken:  "1",
+		},
+		{
+			name:       "next page",
+			url:        "/v1/packages/example.com?version=v1.0.0&limit=1&token=1",
+			wantStatus: http.StatusOK,
+			wantCount:  1,
+			wantTotal:  2,
 		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
@@ -428,6 +446,12 @@ func TestServeModulePackages(t *testing.T) {
 				if len(got.Items) != test.wantCount {
 					t.Errorf("count = %d, want %d", len(got.Items), test.wantCount)
 				}
+				if got.Total != test.wantTotal {
+					t.Errorf("total = %d, want %d", got.Total, test.wantTotal)
+				}
+				if got.NextPageToken != test.wantToken {
+					t.Errorf("token = %q, want %q", got.NextPageToken, test.wantToken)
+				}
 			}
 		})
 	}