add optional flag to skip pagination arg validation (#48101)

There are some resources we want to optionally pagination, for example,
RBAC permissions. When a user loads the Sourcegraph web app, we need to
fetch all permissions assigned to that user to figure out access
control.
This PR adds a field to `ConnectionResolverOptions` called
`SkipArgsValidation`, which skips the check to ensure `First` or `Last`
is set when accessing a paginated resource. The field is false by
default to enforce pagination for new and existing resources and I've
added a comment so anyone making use of it understands the performance
implications of setting it to `true`.



## Test plan

<!-- All pull requests REQUIRE a test plan:
https://docs.sourcegraph.com/dev/background-information/testing_principles
-->
* Manually tested
* Added unit tests

cmd/frontend/graphqlbackend/graphqlutil/connection_resolver.go

@@ -64,6 +64,11 @@ type ConnectionResolverOptions struct {
 	OrderBy database.OrderBy
 	// Order direction.
 	Ascending bool
+
+	// If set to true, the resolver won't throw an error when `first` or `last` isn't provided
+	// in `ConnectionResolverArgs`. Be careful when setting this to true, as this could cause
+	// performance issues when fetching large data.
+	AllowNoLimit bool
 }
 
 // MaxPageSizeOrDefault returns the configured max page limit for the connection.
@@ -118,7 +123,7 @@ func (r *ConnectionResolver[N]) paginationArgs() (*database.PaginationArgs, erro
 		paginationArgs.First = &limit
 	} else if r.args.Last != nil {
 		paginationArgs.Last = &limit
-	} else {
+	} else if !r.options.AllowNoLimit {
 		return nil, errors.New("you must provide a `first` or `last` value to properly paginate")
 	}
 

cmd/frontend/graphqlbackend/graphqlutil/connection_resolver_test.go

@@ -144,12 +144,19 @@ func TestConnectionTotalCount(t *testing.T) {
 	}
 }
 
-func testResolverNodesResponse(t *testing.T, resolver *ConnectionResolver[*testConnectionNode], store *testConnectionStore, count int) {
+func testResolverNodesResponse(t *testing.T, resolver *ConnectionResolver[*testConnectionNode], store *testConnectionStore, count int, wantErr bool) {
 	ctx := context.Background()
 	nodes, err := resolver.Nodes(ctx)
-	if err != nil {
+	if wantErr {
+		if err == nil {
+			t.Fatalf("expected error, got %v", err)
+		}
+		return
+	}
+	if err != nil && !wantErr {
 		t.Fatal(err)
 	}
+
 	if diff := cmp.Diff(count, len(nodes)); diff != "" {
 		t.Fatal(diff)
 	}
@@ -172,7 +179,9 @@ func TestConnectionNodes(t *testing.T) {
 	for _, test := range []struct {
 		name           string
 		connectionArgs *ConnectionResolverArgs
+		options        *ConnectionResolverOptions
 
+		wantError          bool
 		wantPaginationArgs *database.PaginationArgs
 		wantNodes          int
 	}{
@@ -206,15 +215,28 @@ func TestConnectionNodes(t *testing.T) {
 			connectionArgs:     withBeforeCA("0", withLastCA(1, &ConnectionResolverArgs{})),
 			wantNodes:          1,
 		},
+		{
+			name:           "no args supplied (skipArgValidation is false)",
+			connectionArgs: &ConnectionResolverArgs{},
+			options:        &ConnectionResolverOptions{AllowNoLimit: false},
+			wantError:      true,
+		},
+		{
+			name:           "no args supplied (skipArgValidation is true)",
+			connectionArgs: &ConnectionResolverArgs{},
+			options:        &ConnectionResolverOptions{AllowNoLimit: true},
+			wantError:      false,
+			wantNodes:      2,
+		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			store := &testConnectionStore{t: t, expectedPaginationArgs: test.wantPaginationArgs}
-			resolver, err := NewConnectionResolver[*testConnectionNode](store, test.connectionArgs, nil)
+			resolver, err := NewConnectionResolver[*testConnectionNode](store, test.connectionArgs, test.options)
 			if err != nil {
 				t.Fatal(err)
 			}
 
-			testResolverNodesResponse(t, resolver, store, test.wantNodes)
+			testResolverNodesResponse(t, resolver, store, test.wantNodes, test.wantError)
 		})
 	}
 }