fix regridder test warnings

test/TestHelper.jl

@@ -86,7 +86,7 @@ function gen_ncdata(FT, path, varname, val)
     # Define dataset information
     NCDatasets.defDim(nc, "lon", 64)
     NCDatasets.defDim(nc, "lat", 32)
-    nc.attrib["title"] = "this is an NCDataset containing all 1s on a lat/lon grid"
+    nc.attrib["title"] = "this is an NCDataset containing the same value at each point on a lat/lon grid"
 
     # Define variables
     lon = NCDatasets.defVar(nc, "lon", FT, ("lon",))
@@ -103,4 +103,34 @@ function gen_ncdata(FT, path, varname, val)
     close(nc)
 end
 
+function gen_ncdata_time(FT, path, varname, val)
+    isfile(path) && rm(path)
+
+    # Create dataset of all ones
+    nc = NCDatasets.NCDataset(path, "c")
+
+    # Define dataset information
+    NCDatasets.defDim(nc, "lon", 64)
+    NCDatasets.defDim(nc, "lat", 32)
+    NCDatasets.defDim(nc, "time", 2)
+    nc.attrib["title"] = "this is an NCDataset containing the same value at each point on a lat/lon grid at two times"
+
+    # Define variables
+    lon = NCDatasets.defVar(nc, "lon", FT, ("lon",))
+    lat = NCDatasets.defVar(nc, "lat", FT, ("lat",))
+    time = NCDatasets.defVar(nc, "time", Float64, ("time",))
+    v = NCDatasets.defVar(nc, varname, FT, ("lon", "lat", "time"))
+
+    # Populate lon and lat
+    lon[:] = [i for i in 0.0:(360 / 64):(360 - (360 / 64))]
+    lat[:] = [i for i in (-90 + (180 / 64)):(180 / 32):(90 - (180 / 64))]
+    time[:] = [Float64(i) for i in 1:2]
+
+    # Generate some example data and write it to v
+    v[:, :, 1] = [val * 0 for i in 1:nc.dim["lon"], j in 1:nc.dim["lat"]]
+    v[:, :, 2] = [val for i in 1:nc.dim["lon"], j in 1:nc.dim["lat"]]
+
+    close(nc)
+end
+
 end

test/regridder_tests.jl

@@ -1,7 +1,7 @@
 #=
     Unit tests for ClimaCoupler Regridder module
 =#
-import Test: @testset, @test
+import Test: @testset, @test, @test_logs
 import Dates
 import NCDatasets
 import ClimaComms
@@ -139,6 +139,26 @@ for FT in (Float32, Float64)
         @test all(parent(combined_field) .== FT(sum(fractions) * sum(fields) / length(fields)))
     end
 
+    @testset "test get_time" begin
+        # Set up regrid directory for this test only
+        mktempdir(pwd()) do regrid_dir
+            # Test dataset containing times
+            data_path = joinpath(regrid_dir, "data_times.nc")
+            varname = "test_data"
+            TestHelper.gen_ncdata_time(FT, data_path, varname, FT(1))
+            NCDatasets.NCDataset(data_path, "r") do ds
+                @test Regridder.get_time(ds) == Dates.DateTime.(Array(ds["time"]))
+            end
+
+            # Test warning when no dates are available in input data file
+            data_path = joinpath(regrid_dir, "data_no_times.nc")
+            varname = "test_data"
+            TestHelper.gen_ncdata(FT, data_path, varname, FT(1))
+            NCDatasets.NCDataset(data_path, "r") do ds
+                @test_logs (:warn, "No dates available in input data file") Regridder.get_time(ds)
+            end
+        end
+    end
 
     # Add tests which use TempestRemap here -
     # TempestRemap is not built on Windows because of NetCDF support limitations
@@ -193,7 +213,7 @@ for FT in (Float32, Float64)
                 # Initialize dataset of all ones
                 data_path = joinpath(regrid_dir, "ls_mask_data.nc")
                 varname = "test_data"
-                TestHelper.gen_ncdata(FT, data_path, varname, FT(1))
+                TestHelper.gen_ncdata_time(FT, data_path, varname, FT(1))
 
                 # Test monotone masking
                 land_fraction_mono =
@@ -219,7 +239,7 @@ for FT in (Float32, Float64)
                 # Initialize dataset of all 0.5s
                 data_path = joinpath(regrid_dir, "ls_mask_data.nc")
                 varname = "test_data_halves"
-                TestHelper.gen_ncdata(FT, data_path, varname, FT(0.5))
+                TestHelper.gen_ncdata_time(FT, data_path, varname, FT(0.5))
 
                 # Test non-monotone masking
                 land_fraction_halves =