Figure.coast/pygmt.grdlandmask/pygmt.select: Refactor to use the new alias system for parameter 'resolution' (#4013)

* Figure.coast: Refactor using the new alias system

* pygmt.grdlandmask: Refactor using the new alias system

* pygmt.select: Refactor using the new alias system

* Remove the unused _parse_coastline_resolution function

* Remove the test_coast_resolution_short_form test

Author: seisman

pygmt/src/_common.py

@@ -244,55 +244,3 @@ def from_params(
             if set(param_list).issubset(set(params)):
                 return cls(convention, component=component)
         raise GMTValueError(params, description="focal mechanism parameters")
-
-
-def _parse_coastline_resolution(
-    resolution: Literal["auto", "full", "high", "intermediate", "low", "crude", None],
-) -> Literal["a", "f", "h", "i", "l", "c", None]:
-    """
-    Parse the 'resolution' parameter for coastline-related functions.
-
-    Parameters
-    ----------
-    resolution
-        The resolution of the coastline dataset to use. The available resolutions from
-        highest to lowest are: ``"full"``, ``"high"``, ``"intermediate"``, ``"low"``,
-        and ``"crude"``, which drops by 80% between levels. Alternatively, choose
-        ``"auto"`` to automatically select the most suitable resolution given the chosen
-        map scale or region. ``None`` means using the default resolution.
-
-    Returns
-    -------
-    The single-letter resolution code or ``None``.
-
-    Raises
-    ------
-    GMTValueError
-        If the resolution is invalid.
-
-    Examples
-    --------
-    >>> _parse_coastline_resolution("full")
-    'f'
-    >>> _parse_coastline_resolution("f")
-    'f'
-    >>> _parse_coastline_resolution(None)
-    >>> _parse_coastline_resolution("invalid")
-    Traceback (most recent call last):
-    ...
-    pygmt...GMTValueError: Invalid .... Expected ....
-    """
-    if resolution is None:
-        return None
-
-    _valid_res = {"auto", "full", "high", "intermediate", "low", "crude"}
-
-    if resolution in _valid_res:  # Long-form arguments.
-        return resolution[0]  # type: ignore[return-value]
-
-    if resolution in {_res[0] for _res in _valid_res}:  # Short-form arguments.
-        return resolution  # type: ignore[return-value]
-
-    raise GMTValueError(
-        resolution, choices=_valid_res, description="GSHHG coastline resolution"
-    )

pygmt/src/coast.py

@@ -14,7 +14,6 @@
     kwargs_to_strings,
     use_alias,
 )
-from pygmt.src._common import _parse_coastline_resolution
 
 __doctest_skip__ = ["coast"]
 
@@ -24,7 +23,6 @@
     A="area_thresh",
     B="frame",
     C="lakes",
-    D="resolution-",
     E="dcw",
     F="box",
     G="land",
@@ -68,6 +66,7 @@ def coast(
     Full GMT docs at :gmt-docs:`coast.html`.
 
     {aliases}
+       - D=resolution
        - J=projection
 
     Parameters
@@ -214,9 +213,19 @@ def coast(
         )
         raise GMTInvalidInput(msg)
 
-    kwargs["D"] = kwargs.get("D", _parse_coastline_resolution(resolution))
-
     aliasdict = AliasSystem(
+        D=Alias(
+            resolution,
+            name="resolution",
+            mapping={
+                "auto": "a",
+                "full": "f",
+                "high": "h",
+                "intermediate": "i",
+                "low": "l",
+                "crude": "c",
+            },
+        ),
         J=Alias(projection, name="projection"),
     ).merge(kwargs)
 

pygmt/src/grdlandmask.py

@@ -16,15 +16,13 @@
     kwargs_to_strings,
     use_alias,
 )
-from pygmt.src._common import _parse_coastline_resolution
 
 __doctest_skip__ = ["grdlandmask"]
 
 
 @fmt_docstring
 @use_alias(
     A="area_thresh",
-    D="resolution-",
     I="spacing",
     R="region",
     V="verbose",
@@ -53,6 +51,7 @@ def grdlandmask(
     Full GMT docs at :gmt-docs:`grdlandmask.html`.
 
     {aliases}
+       - D=resolution
        - E=bordervalues
        - N=maskvalues
 
@@ -118,9 +117,19 @@ def grdlandmask(
         msg = "Both 'region' and 'spacing' must be specified."
         raise GMTInvalidInput(msg)
 
-    kwargs["D"] = kwargs.get("D", _parse_coastline_resolution(resolution))
-
     aliasdict = AliasSystem(
+        D=Alias(
+            resolution,
+            name="resolution",
+            mapping={
+                "auto": "a",
+                "full": "f",
+                "high": "h",
+                "intermediate": "i",
+                "low": "l",
+                "crude": "c",
+            },
+        ),
         N=Alias(maskvalues, name="maskvalues", sep="/", size=(2, 5)),
         E=Alias(bordervalues, name="bordervalues", sep="/", size=4),
     ).merge(kwargs)

pygmt/src/select.py

@@ -16,7 +16,6 @@
     use_alias,
     validate_output_table_type,
 )
-from pygmt.src._common import _parse_coastline_resolution
 
 __doctest_skip__ = ["select"]
 
@@ -78,6 +77,7 @@ def select(
     Full GMT docs at :gmt-docs:`gmtselect.html`.
 
     {aliases}
+       - D=resolution
        - J=projection
 
     Parameters
@@ -211,15 +211,25 @@ def select(
     >>> # longitudes 246 and 247 and latitudes 20 and 21
     >>> out = pygmt.select(data=ship_data, region=[246, 247, 20, 21])
     """
-    kwargs["D"] = kwargs.get("D", _parse_coastline_resolution(resolution))
-
     output_type = validate_output_table_type(output_type, outfile=outfile)
 
     column_names = None
     if output_type == "pandas" and isinstance(data, pd.DataFrame):
         column_names = data.columns.to_list()
 
     aliasdict = AliasSystem(
+        D=Alias(
+            resolution,
+            name="resolution",
+            mapping={
+                "auto": "a",
+                "full": "f",
+                "high": "h",
+                "intermediate": "i",
+                "low": "l",
+                "crude": "c",
+            },
+        ),
         J=Alias(projection, name="projection"),
     ).merge(kwargs)
 

pygmt/tests/test_coast.py

@@ -76,26 +76,6 @@ def test_coast_dcw_list():
     return fig
 
 
-@pytest.mark.mpl_image_compare(filename="test_coast_world_mercator.png")
-def test_coast_resolution_short_form():
-    """
-    Test using the short form of the 'resolution' parameter.
-
-    This test is the same as test_coast_world_mercator, but uses the short form of
-    the 'resolution' parameter.
-    """
-    fig = Figure()
-    fig.coast(
-        region=[-180, 180, -80, 80],
-        projection="M15c",
-        frame="af",
-        land="#aaaaaa",
-        D="crude",
-        water="white",
-    )
-    return fig
-
-
 def test_coast_resolution_long_short_form_conflict():
     """
     Test that using the short form of the 'resolution' parameter conflicts with