migrate functions and add tests

Author: ayushjariyal

python/grass/jupyter/tests/utils_test.py

@@ -0,0 +1,60 @@
+import pytest
+import grass.script as gs
+from grass.tools import Tools
+from grass.jupyter.utils import *
+
+
+def test_get_region(session_with_data):
+    """Check that get_region returns a dictionary with region bounds"""
+    region = get_region(env=session_with_data.env)
+    
+    assert isinstance(region, dict)
+    assert "north" in region
+    assert "south" in region
+    assert "east" in region
+    assert "west" in region
+
+def test_get_location_proj_string(tmp_path):
+    """Test that get_location_proj_string returns the projection of the environment in PROJ.4 format."""
+    project = tmp_path / "test_project_proj"
+    gs.create_project(project)
+    with gs.setup.init(project):
+        gs.run_command("g.proj", flags="c", epsg="4326")
+        projection = get_location_proj_string()
+        assert "+proj=" in projection
+
+def test_reproject_region(session_with_data):
+    """Check that a region is correctly reprojected between two projections"""
+    reg = {"north": 100000.0, "south": 0.0, "east": 100000.0, "west": 0.0, "rows": 10, "cols": 10}
+    p_in = "+proj=merc +a=6378137 +b=6378137 +units=m +type=crs"
+    p_out = "+proj=longlat +datum=WGS84 +type=crs"
+    
+    res = reproject_region(reg, p_in, p_out, env=session_with_data.env)
+    
+    assert isinstance(res, dict) and "north" in res
+    assert res["north"] != reg["north"] and res["east"] != reg["east"]
+    assert -90 <= res["north"] <= 90 and -180 <= res["east"] <= 180
+
+def test_set_target_region(session_with_data, tmp_path):
+    """Check setting a target region in a newly created environment"""
+    gisdbase = str(tmp_path)
+
+    # Helper to quickly spin up isolated GRASS locations
+    def make_env(loc_name, epsg):
+        _, env = gs.create_environment(gisdbase, loc_name, "PERMANENT")
+        gs.create_location(gisdbase, loc_name, epsg=epsg, overwrite=True)
+        full_env = session_with_data.env.copy()
+        full_env["GISRC"] = env["GISRC"]
+        return full_env
+
+    # 1. Setup Source and Target
+    src_env = make_env("src_loc", "3857")
+    tgt_env = make_env("tgt_loc", "4326")
+
+    # 2. Add data to source, then execute function
+    Tools(env=src_env).g_region(n=1000, s=0, e=1000, w=0, rows=10, cols=10)
+    set_target_region(src_env, tgt_env)
+
+    # 3. Verify
+    res = get_region(env=tgt_env)
+    assert isinstance(res, dict) and "north" in res and "south" in res

python/grass/jupyter/utils.py

@@ -35,7 +35,7 @@ def get_location_proj_string(env=None):
     return tools.g_proj(flags="fp", format="proj4").text
 
 
-def reproject_region(region, from_proj, to_proj):
+def reproject_region(region, from_proj, to_proj, env=None):
     """Reproject boundary of region from one projection to another.
 
     :param dict region: region to reproject as a dictionary with long key names
@@ -47,6 +47,7 @@ def reproject_region(region, from_proj, to_proj):
     :return dict region: reprojected region as a dictionary with long key names
     """
     region = region.copy()
+    tools = Tools(env=env)
     # reproject all corners, otherwise reproj. region may be underestimated
     # even better solution would be reprojecting vector region like in r.import
     proj_input = (
@@ -55,28 +56,25 @@ def reproject_region(region, from_proj, to_proj):
         f"{region['east']} {region['south']}\n"
         f"{region['west']} {region['south']}\n"
     )
-    proc = gs.start_command(
-        "m.proj",
-        input="-",
-        separator=" , ",
-        proj_in=from_proj,
-        proj_out=to_proj,
-        flags="d",
-        stdin=gs.PIPE,
-        stdout=gs.PIPE,
-        stderr=gs.PIPE,
-    )
-    proj_output, stderr = proc.communicate(proj_input)
-    if proc.returncode:
-        raise RuntimeError(
-            _("Encountered error while running m.proj: {}").format(stderr)
+    
+    with tempfile.NamedTemporaryFile(mode="w+t") as temp_file:
+        temp_file.write(proj_input)
+        temp_file.flush()
+
+        tools = Tools(env=env)
+        result = tools.m_proj(
+            input=temp_file.name,
+            separator=",",
+            proj_in=from_proj,
+            proj_out=to_proj,
+            flags="d",
         )
-    output = proj_output.splitlines()
+        output = result.text.splitlines()
     # get the largest bbox
     latitude_list = []
     longitude_list = []
     for row in output:
-        longitude, latitude, unused = row.split(" ")
+        longitude, latitude, unused = row.split(",")
         longitude_list.append(float(longitude))
         latitude_list.append(float(latitude))
     region["east"] = max(longitude_list)
@@ -355,17 +353,16 @@ def set_target_region(src_env, tgt_env):
     region = get_region(env=src_env)
     from_proj = get_location_proj_string(src_env)
     to_proj = get_location_proj_string(env=tgt_env)
-    new_region = reproject_region(region, from_proj, to_proj)
+    new_region = reproject_region(region, from_proj, to_proj, env=src_env)
     # Set region to match original region extent
-    gs.run_command(
-        "g.region",
+    tools = Tools(env=tgt_env)
+    tools.g_region(
         n=new_region["north"],
         s=new_region["south"],
         e=new_region["east"],
         w=new_region["west"],
         rows=new_region["rows"],
         cols=new_region["cols"],
-        env=tgt_env,
     )