Attempt supporting multi-file version constraints

conda_lock/models/lock_spec.py

@@ -1,3 +1,6 @@
+from __future__ import annotations
+
+import copy
 import hashlib
 import json
 import pathlib
@@ -24,23 +27,123 @@ class _BaseDependency(StrictModel):
     def sorted_extras(cls, v: List[str]) -> List[str]:
         return sorted(v)
 
+    def _merge_base(self, other: _BaseDependency) -> _BaseDependency:
+        if other is None:
+            return self
+        if (
+            self.name != other.name
+            or self.manager != other.manager
+            or self.category != other.category
+        ):
+            raise ValueError(
+                "Cannot merge incompatible dependencies: {self} != {other}"
+            )
+        return _BaseDependency(
+            name=self.name,
+            manager=self.manager,
+            category=self.category,
+            extras=list(set(self.extras + other.extras)),
+        )
+
 
 class VersionedDependency(_BaseDependency):
     version: str
     build: Optional[str] = None
     conda_channel: Optional[str] = None
 
+    @staticmethod
+    def _merge_constraints(
+        constraint1: Optional[str], constraint2: Optional[str]
+    ) -> Optional[str]:
+        # Must return a copy!
+        if constraint1 == constraint2:
+            copy.copy(constraint1)
+        if constraint1 is None or constraint1 == "":
+            copy.copy(constraint2)
+        if constraint2 is None or constraint2 == "":
+            copy.copy(constraint1)
+        return f"{constraint1},{constraint2}"
+
+    def merge(self, other: Optional[VersionedDependency]) -> VersionedDependency:
+        if other is None:
+            return self
+
+        if (
+            self.conda_channel is not None
+            and other.conda_channel is not None
+            and self.conda_channel != other.conda_channel
+        ):
+            raise ValueError(
+                f"VersionedDependency has two different conda_channels:\n{self}\n{other}"
+            )
+        merged_base = self._merge_base(other)
+        return VersionedDependency(
+            name=merged_base.name,
+            manager=merged_base.manager,
+            category=merged_base.category,
+            extras=merged_base.extras,
+            version=self._merge_constraints(self.version, other.version),  # type: ignore
+            build=self._merge_constraints(self.build, other.build),
+            conda_channel=self.conda_channel or other.conda_channel,
+        )
+
 
 class URLDependency(_BaseDependency):
     url: str
     hashes: List[str]
 
+    def merge(self, other: Optional[URLDependency]) -> URLDependency:
+        if other is None:
+            return self
+        if self.url != other.url:
+            raise ValueError(f"URLDependency has two different urls:\n{self}\n{other}")
+
+        if self.hashes != other.hashes:
+            raise ValueError(
+                f"URLDependency has two different hashess:\n{self}\n{other}"
+            )
+        merged_base = self._merge_base(other)
+
+        return URLDependency(
+            name=merged_base.name,
+            manager=merged_base.manager,
+            category=merged_base.category,
+            extras=merged_base.extras,
+            url=self.url,
+            hashes=self.hashes,
+        )
+
 
 class VCSDependency(_BaseDependency):
     source: str
     vcs: str
     rev: Optional[str] = None
 
+    def merge(self, other: Optional[VCSDependency]) -> VCSDependency:
+        if other is None:
+            return self
+        if self.source != other.source:
+            raise ValueError(
+                f"VCSDependency has two different sources:\n{self}\n{other}"
+            )
+
+        if self.vcs != other.vcs:
+            raise ValueError(f"VCSDependency has two different vcss:\n{self}\n{other}")
+
+        if self.rev is not None and other.rev is not None and self.rev != other.rev:
+            raise ValueError(f"VCSDependency has two different revs:\n{self}\n{other}")
+        merged_base = self._merge_base(other)
+
+        return VCSDependency(
+            name=merged_base.name,
+            manager=merged_base.manager,
+            category=merged_base.category,
+            extras=merged_base.extras,
+            source=self.source,
+            vcs=self.vcs,
+            rev=self.rev or other.rev,
+        )
+
 
 Dependency = Union[VersionedDependency, URLDependency, VCSDependency]
 

conda_lock/src_parser/aggregation.py

@@ -34,7 +34,11 @@ def aggregate_lock_specs(
             lock_spec.dependencies.get(platform, []) for lock_spec in lock_specs
         ):
             key = (dep.manager, dep.name)
-            unique_deps[key] = dep
+            if unique_deps.get(key) is not None and type(unique_deps[key]) != type(dep):
+                raise ValueError(
+                    f"Unsupported use of different dependency types for same package:\n{dep}\n{unique_deps[key]}"
+                )
+            unique_deps[key] = dep.merge(unique_deps.get(key))  # type: ignore
 
         dependencies[platform] = list(unique_deps.values())
 

tests/test_conda_lock.py

@@ -1622,22 +1622,28 @@ def test_aggregate_lock_specs():
     assert actual.content_hash() == expected.content_hash()
 
 
-def test_aggregate_lock_specs_override_version():
-    base_spec = LockSpecification(
-        dependencies={"linux-64": [_make_spec("package", "=1.0")]},
+def test_aggregate_lock_specs_combine_version():
+    first_spec = LockSpecification(
+        dependencies={"linux-64": [_make_spec("package", ">1.0")]},
         channels=[Channel.from_string("conda-forge")],
         sources=[Path("base.yml")],
     )
 
-    override_spec = LockSpecification(
-        dependencies={"linux-64": [_make_spec("package", "=2.0")]},
+    second_spec = LockSpecification(
+        dependencies={"linux-64": [_make_spec("package", "<2.0")]},
+        channels=[Channel.from_string("internal"), Channel.from_string("conda-forge")],
+        sources=[Path("additional.yml")],
+    )
+
+    result_spec = LockSpecification(
+        dependencies={"linux-64": [_make_spec("package", "<2.0,>1.0")]},
         channels=[Channel.from_string("internal"), Channel.from_string("conda-forge")],
-        sources=[Path("override.yml")],
+        sources=[Path("additional.yml")],
     )
 
-    agg_spec = aggregate_lock_specs([base_spec, override_spec], platforms=["linux-64"])
+    agg_spec = aggregate_lock_specs([first_spec, second_spec], platforms=["linux-64"])
 
-    assert agg_spec.dependencies == override_spec.dependencies
+    assert agg_spec.dependencies == result_spec.dependencies
 
 
 def test_aggregate_lock_specs_invalid_channels():