resample: close test-coverage gaps surfaced by deep-sweep audit

.claude/sweep-test-coverage-state.csv

@@ -10,4 +10,5 @@ polygonize,2026-05-27,2537,MEDIUM,4,"Pass 2 (2026-05-27): added test_polygonize_
 rasterize,2026-05-21,2255,HIGH,1;2;3,"Pass 2 (2026-05-21): added test_rasterize_coverage_2026_05_21.py with 58 tests, all passing on a CUDA host. Closes Cat 2 HIGH +/-Inf and NaN burn-value gaps that pass-1 left untouched: pin +Inf / -Inf / Inf+(-Inf)/NaN polygon, point, and line burn behaviour across numpy / cupy / dask+numpy / dask+cupy, plus Inf+finite under sum stays Inf, Inf+(-Inf) under sum collapses to NaN, min(Inf, 1.0) and max(-Inf, 1.0) pick the finite value, and Inf-as-bound is rejected with the same ValueError as NaN-as-bound (pass-1 only tested the NaN-bound rejection). Closes Cat 1 MEDIUM nested GeometryCollection on all four backends: a GC inside a GC has no direct test today even though rasterize.py:1995 documents recursive unpacking, and the deeply-nested-3-levels eager test pins the recursion depth limit isn't 1 or 2. Closes Cat 1 MEDIUM columns= (multi-column) parity on cupy and dask+cupy (TestMultiColumn covered numpy/dask+numpy only); pin three columns of props on GPU so the (N, P) loop survives the kernel boundary. Closes Cat 3 LOW rectangular-pixel parity with resolution=(rx, ry) across backends. Filed source-bug issue #2255: GPU max/min merge silently suppresses NaN burn values -- CPU returns NaN (1.0 > NaN is False, keeps NaN); GPU returns 1.0 because the kernel inits the output buffer to -inf for max (or +inf for min) and atomicMax/Min is NaN-suppressing under IEEE device semantics. Pinned both the CPU NaN-propagating behaviour and the GPU NaN-suppressing behaviour as paired tests (test_nan_burn_overlaps_max_cpu_propagates vs test_nan_burn_overlaps_max_gpu_suppresses_nan, plus test_nan_burn_single_geom_max_gpu_returns_neg_inf for the single-write-on-GPU-returns-buffer-init case) so the divergence is visible in CI until the GPU kernels are aligned. Source untouched. Pass 1 (2026-05-17): added test_rasterize_coverage_2026_05_17.py with 34 tests, all passing on a CUDA host. Closes four documented public-API gaps left after the pass-0 audit. (1) Cat 3 HIGH 1x1 single-pixel raster -- test_rasterize.py covers 1xN strips and Nx1 strips but never width=1 AND height=1, so the polygon scanline / line Bresenham / point burn kernels all ship without the single-cell degenerate case; the new TestSinglePixelRaster class pins polygon/point/line on eager numpy plus polygon parity across cupy / dask+numpy / dask+cupy. (2) Cat 4 HIGH like= template-raster parameter is documented at rasterize.py:2038 and implemented by _extract_grid_from_like (line 1930) but no test exercises it; TestLikeParameter pins dtype/bounds/coords inheritance, the three override branches (dtype, bounds, width/height), the three validation branches (not-DataArray, 3D, wrong dim names) and like= on all four backends. Mutation against the like-dtype branch (rasterize.py:2183-2184) flipped the inheritance test red. (3) Cat 4 HIGH resolution= happy path -- only the oversize-rejection error path was tested (line 304); TestResolutionParameter pins the scalar branch, the tuple branch, the ceil-and-clamp-to-1 semantics, and resolution= on all four backends. (4) Cat 4 HIGH non-empty GeometryCollection unpacking is documented at rasterize.py:1995 and implemented by _classify_geometries_loop (line 228) but only the empty-GC case was tested (line 269); TestGeometryCollection pins polygon+point and polygon+line+point collections on eager numpy plus parity across cupy / dask+numpy / dask+cupy so the loop classifier's polygon/line/point sub-bucketing has direct coverage. Cat 1 MEDIUM gap closed: eager cupy all_touched=True parity vs eager numpy (TestEagerCupyAllTouched) -- the existing test only covered dask+cupy all_touched, leaving the direct GPU all_touched kernel untested. Cat 2 MEDIUM gap closed: int32 dtype with default NaN fill silently casts to the int32-min sentinel (TestIntegerDtypeNanFill) -- pin the cast so any future ValueError-raises switch is visible as a code-review diff. Pre-existing 143 passing + 2 skipped tests in test_rasterize.py untouched."
 reproject,2026-05-27,,MEDIUM,1,"Pass 2 (2026-05-27): added test_reproject_coverage_2026_05_27.py with 10 tests, all passing on a CUDA host. Closes Cat 1 MEDIUM backend-coverage gaps left after pass 1: (a) bounds_policy=#2187 had numpy + dask+numpy coverage but no cupy / dask+cupy tests -- a regression dropping the kwarg from the GPU dispatchers would ship undetected; TestBoundsPolicyCupy and TestBoundsPolicyDaskCupy pin raw/clamp/bogus on both GPU backends and assert clamp-grid parity with numpy. (b) test_reproject_handles_inf_input only covered eager numpy; the dask, cupy, and dask+cupy chunk workers each ship their own bilinear/cubic resampler so a regression raising on +/-Inf in any one backend would not surface from the existing test. Four new tests close the matrix (dask+numpy, cupy, dask+cupy with scattered +/-Inf cells; cupy with all-Inf raster checking no spurious finite cells appear). Note carried forward from pass 1: _merge_arrays_cupy is imported but unused -- no cupy merge dispatch in merge(); feature gap not test gap. Added 39 tests: LiteCRS direct coverage, itrf_transform behaviour/roundtrip/array, itrf_frames, geoid_height numerical correctness + raster happy-path, vertical helpers (ellipsoidal<->orthometric/depth), reproject() lat/lon and latitude/longitude dim propagation. Note: _merge_arrays_cupy is imported but unused (no cupy merge dispatch in merge()); flagged as feature gap not test gap."
 reproject,2026-05-10,,HIGH,1;4;5,"Added 39 tests: LiteCRS direct coverage, itrf_transform behaviour/roundtrip/array, itrf_frames, geoid_height numerical correctness + raster happy-path, vertical helpers (ellipsoidal<->orthometric/depth), reproject() lat/lon and latitude/longitude dim propagation. Note: _merge_arrays_cupy is imported but unused (no cupy merge dispatch in merge()); flagged as feature gap not test gap."
+resample,2026-05-27,2547,HIGH,2;3;5,"Pass 1 (2026-05-27): added test_resample_coverage_2026_05_27.py with 70 tests (68 passing, 2 skipped). Closes Cat 3 HIGH Nx1 single-column gap across numpy/cupy/dask+numpy/dask+cupy x 8 methods (nearest/bilinear/cubic/average/min/max/median/mode) plus Nx1 upsample-nearest parity and Nx1 cross-backend aggregate parity. Closes Cat 2 MEDIUM NaN-parity gap on cupy and dask+cupy (existing TestCuPyParity/TestDaskCuPyParity used random data without NaN; the weight-mask gate and spline-prepad had no GPU NaN coverage). Closes Cat 3 MEDIUM all-equal-value raster across 8 methods (downsample) and 3 interp methods (upsample) plus a constant-with-NaN aggregate variant. Closes Cat 5 MEDIUM non-default dim-name propagation: lat/lon, latitude/longitude, and (channel, lat, lon) 3D round-trip without being renamed to y/x; per-dim attrs (units) preserved. Closes Cat 3 MEDIUM empty-raster behaviour pin: 0-row and 0-col rasters raise (currently IndexError) -- contract covered. Filed source-bug issue #2547: cubic on dask backends fails for Nx1 / arrays smaller than depth=16; the 2 skipped tests in this file gate on that fix landing. Source untouched."
 zonal,2026-05-27,,HIGH,1;3;4;5,"Pass 1 (2026-05-27): added test_zonal_backend_coverage_2026_05_27.py with 32 tests, all passing on a CUDA host. Closes Cat 1 HIGH backend-coverage gaps: crosstab cupy + dask+cupy (_crosstab_cupy / _crosstab_dask_cupy were dispatched but never invoked by tests), regions cupy + dask+cupy (_regions_cupy via cupyx.scipy.ndimage + _regions_dask_cupy), trim dask+numpy + cupy + dask+cupy (_trim_bounds_dask isnan path and cupy data.get() path), crop dask+numpy + cupy + dask+cupy (_crop_bounds_dask + cupy data.get() path), apply 3D cupy + dask+cupy (per-layer kernel launch over the third axis in _apply_cupy and _apply_dask_cupy). Existing test_zonal.py covered only numpy + dask+numpy for crosstab/regions/trim/crop and 2D-only for cupy apply. Closes Cat 3 MEDIUM 1x1 / 1xN / Nx1 strip edge cases for trim, crop, and regions. Closes Cat 4 LOW pins: regions(neighborhood=6) ValueError, suggest_zonal_canvas(crs='Geographic') aspect-ratio pin and invalid-crs KeyError, crosstab cupy zone_ids/cat_ids filter, crosstab cupy agg='percentage'. Closes Cat 5 MEDIUM: regions coords/attrs propagation across numpy + dask+numpy, trim/crop name='trim'/'crop' default + attrs preservation. Also pins the documented numpy-vs-dask trim asymmetry on NaN sentinel (numpy _trim does equality which never matches NaN; dask _trim_bounds_dask has dedicated isnan branch). Mutation against the cupy.asnumpy() conversion in _crosstab_cupy flipped test_crosstab_cupy_matches_numpy red. Source untouched."