Allow predicates in crop, closing #6

R/geometry_operation.R

@@ -75,16 +75,22 @@ st_n_intersects <- function(x, y) st_n_pred(x, y, st_intersects)
             .g <- gs[[s]][, c("geometry", id_col)]
             st_agr(.g) <- "constant"
             o <- op(.g, y_use)
-            # Aggregate in case cropping broke some items into multiple pieces
-            if (any(!rownames(o) %in% rownames(.g))) {
-                o <- aggregate(o,
-                    by = setNames(list(id = o[[id_col]]), id_col),
-                    FUN = unique
-                )
+            # If it's a predicate
+            if (is(o, "sgbp")) {
+                inds <- lengths(o) > 0L
+                return(gs[[s]][inds,])
+            } else {
+                # Aggregate in case cropping broke some items into multiple pieces
+                if (any(!rownames(o) %in% rownames(.g))) {
+                    o <- aggregate(o,
+                                   by = setNames(list(id = o[[id_col]]), id_col),
+                                   FUN = unique
+                    )
+                }
+                return(merge(o, st_drop_geometry(gs[[s]]), by = id_col, all = TRUE))
             }
-            merge(o, st_drop_geometry(gs[[s]]), by = id_col, all = TRUE)
         } else {
-            gs[[s]]
+            return(gs[[s]])
         }
     })
     gs_sub <- do.call(rbind, gs_sub)

tests/testthat/test-geometry_operation.R

@@ -121,8 +121,13 @@ test_that("When a sample is removed by cropping", {
     expect_equal(sampleIDs(sfe_cropped), "sample01")
 })
 
-test_that("Crop to subset with intersection without cropping geometries", {
-
+test_that("Use geometry predicate to crop", {
+    sfe_cropped <- crop(sfe_visium, bbox_use, sample_id = "all", op = st_intersects)
+    cg <- spotPoly(sfe_cropped, "all")
+    expect_true(all(st_any_pred(cg, bbox_use, pred = st_intersects)))
+    # Not actually cropped
+    expect_false(all(st_any_pred(cg, bbox_use, pred = st_covered_by)))
+    expect_true(st_geometry_type(cg, by_geometry = FALSE) == "POLYGON")
 })
 
 annotGeometry(sfe_visium, "bbox", sample_id = "sample01") <- bbox_sf