feat: add to_grc output (#70)

Author: jsstevenson

src/agct/seqref_registry.py

@@ -15,13 +15,28 @@
 class Assembly(StrEnum):
     """Constrain reference genome assembly values.
 
+    Uses UCSC-style names because we're fetching UCSC chainfiles.
+
     We could conceivably support every UCSC chainfile offering, but for now, we'll
     stick with internal use cases only.
     """
 
     HG38 = "hg38"
     HG19 = "hg19"
 
+    @property
+    def as_grc(self) -> str:
+        """Return official Genome Reference Consortium assembly names
+
+        :return: `"GRCh38"` or `"GRCh37"`
+        :raise ValueError: if unrecognized enum option
+        """
+        if self.value == "hg38":
+            return "GRCh38"
+        if self.value == "hg19":
+            return "GRCh37"
+        raise ValueError
+
 
 class Chromosome(StrEnum):
     """Constrain chromosome values to UCSC-style names.

tests/test_seqref_registry.py

@@ -8,6 +8,18 @@
 )
 
 
+def test_assembly_enum():
+    assert Assembly("hg38") == Assembly.HG38
+    assert Assembly.HG38 == "hg38"
+    assert Assembly("hg19") == Assembly.HG19
+    assert Assembly.HG19 == "hg19"
+
+
+def test_assembly_enum_to_ncbi():
+    assert Assembly.HG19.as_grc == "GRCh37"
+    assert Assembly.HG38.as_grc == "GRCh38"
+
+
 def test_assembly_fetcher():
     assert get_seqinfo_from_refget_id("SQ.ss8r_wB0-b9r44TQTMmVTI92884QvBiB") == (
         Assembly.HG38,