fix: checksum util

ethpm_types/manifest.py

@@ -303,15 +303,15 @@ def get_contract_compiler(self, contract_type_name: str) -> Optional[Compiler]:
         Returns:
             Optional[`~ethpm_types.source.Compiler`]
         """
-        for compiler in (self.compilers or []):
-            if contract_type_name in compiler.contractTypes:
+        for compiler in self.compilers or []:
+            if contract_type_name in (compiler.contractTypes or []):
                 return compiler
 
         return None
 
     def update_compilers(self, compilers: List[Compiler]):
         updated_compilers = [*compilers]
-        for prior_compiler in (self.compilers or []):
+        for prior_compiler in self.compilers or []:
             if prior_compiler not in updated_compilers:
                 updated_compilers.append(prior_compiler)
 

ethpm_types/source.py

@@ -73,6 +73,15 @@ class Checksum(BaseModel):
     The hash of a source files contents generated with the corresponding algorithm.
     """
 
+    @classmethod
+    def from_file(cls, file: Union[Path, str], algorithm: Algorithm = Algorithm.MD5) -> "Checksum":
+        source_path = file if isinstance(file, Path) else Path(file)
+        return cls.from_bytes(source_path.read_bytes(), algorithm=algorithm)
+
+    @classmethod
+    def from_bytes(cls, data: bytes, algorithm: Algorithm = Algorithm.MD5) -> "Checksum":
+        return cls(algorithm=algorithm, hash=compute_checksum(data, algorithm=algorithm))
+
 
 class Content(BaseModel):
     """

tests/test_package_manifest.py

@@ -124,7 +124,8 @@ def test_adding_compiler_with_missing_contract():
     compiler = Compiler(name="vyper", version="0.3.7", settings={}, contractTypes=["foobar"])
 
     with pytest.raises(
-            ValidationError, match=r".*Invalid compiler\. Missing compiled contract type 'foobar'*"):
+        ValidationError, match=r".*Invalid compiler\. Missing compiled contract type 'foobar'*"
+    ):
         PackageManifest(compilers=[compiler])
 
 

tests/test_source.py

@@ -1,7 +1,11 @@
+import tempfile
+from pathlib import Path
+
 import pytest
 
 from ethpm_types._pydantic_v1 import FileUrl
-from ethpm_types.source import Compiler, Content, ContractSource, Source
+from ethpm_types.source import Checksum, Compiler, Content, ContractSource, Source
+from ethpm_types.utils import Algorithm, compute_checksum
 
 SOURCE_LOCATION = (
     "https://github.com/OpenZeppelin/openzeppelin-contracts"
@@ -168,3 +172,14 @@ def test_compiler_equality():
     compiler_1.settings["test"] = "123"
     assert compiler_1 != compiler_2
     compiler_1.settings = compiler_2.settings
+
+
+def test_checksum_from_file():
+    file = Path(tempfile.mktemp())
+    file.write_text("foobartest123")
+    actual = Checksum.from_file(file)
+    expected = Checksum(
+        algorithm=Algorithm.MD5,
+        hash=compute_checksum(file.read_bytes()),
+    )
+    assert actual == expected