Add version constraints to cargo dependencies

This change brings support for reading the version constraints from the
dependencies specified in Cargo.toml manifests. It supports the full
range of syntax with the exception of complex wildcards such as `1.*.3`.

The behavior enabled by this change aligns colcon-cargo with other build
system extensions, and will notify the user with a warning during a
build where an incompatible version of a package is present in a
workspace which has one or more other packages requiring a different
version of it.

Author: cottsay

colcon_cargo/package_augmentation/cargo.py

@@ -5,6 +5,7 @@
 
 from colcon_cargo.package_identification.cargo import read_cargo_toml
 from colcon_core.dependency_descriptor import DependencyDescriptor
+from colcon_core.package_augmentation import logger
 from colcon_core.package_augmentation \
     import PackageAugmentationExtensionPoint
 from colcon_core.plugin_system import satisfies_version
@@ -122,6 +123,44 @@ def filter_dependency_list(dependencies, filter_out=None):
     return filtered_dependencies.items()
 
 
+def _next_caret(version):
+    # Drop pre-release
+    version = next(iter(version.split('-', 1)))
+    new_parts = []
+    for part in version.split('.'):
+        value = int(part)
+        if value != 0:
+            new_parts.append(str(value + 1))
+            break
+        new_parts.append(part)
+    else:
+        new_parts[-1] = '1'
+    return '.'.join(new_parts)
+
+
+def _next_tilde(version):
+    # Drop pre-release
+    version = next(iter(version.split('-', 1)))
+    if '.' not in version:
+        return str(int(version) + 1)
+    parts = version.split('.', 2)
+    if len(parts) == 1:
+        return str(int(parts[0]) + 1)
+    return parts[0] + '.' + str(int(parts[1]) + 1)
+
+
+def _convert_wildcards(version):
+    while version.endswith('.*'):
+        version = version[:-2]
+    if version == '*':
+        return '>=0'
+    elif '*' in version:
+        logger.warning(f"Ignoring unsupported version '{version}'")
+        return None
+    else:
+        return '~' + version
+
+
 def create_dependency_descriptor(dependency_name, constraints, path):
     """
     Create a dependency descriptor from a Cargo dependency specification.
@@ -133,6 +172,17 @@ def create_dependency_descriptor(dependency_name, constraints, path):
       resolved
     :rtype: DependencyDescriptor
     """
+    # The checking order matters, so we use tuple instead of dict
+    symbol_mappings = (
+        ('^', 'version_gte', _next_caret),
+        ('~', 'version_gte', _next_tilde),
+        ('>=', 'version_gte', None),
+        ('<=', 'version_lte', None),
+        ('=', 'version_eq', None),
+        ('>', 'version_gt', None),
+        ('<', 'version_lt', None),
+    )
+
     if isinstance(constraints, dict):
         dep_path = constraints.get('path')
         if dep_path:
@@ -141,12 +191,32 @@ def create_dependency_descriptor(dependency_name, constraints, path):
         else:
             source = constraints.get('git') or \
                 constraints.get('registry')
+        versions = constraints.get('version')
     else:
         source = None
+        versions = constraints
+
     metadata = {
         'origin': 'cargo',
         'cargo_source': source,
     }
-    # TODO: Interpret SemVer constraints and add appropriate constraint
-    #       metadata. Handling arbitrary wildcards will be non-trivial.
+    for version in (versions or '').split(','):
+        # Ignore version metadata during comparison
+        version = next(iter(version.split('+', 1))).strip()
+        if '*' in version:
+            version = _convert_wildcards(version)
+        if not version:
+            continue
+        for symbol, mapping, version_lt in symbol_mappings:
+            if version.startswith(symbol):
+                version = version[len(symbol):].lstrip()
+                metadata[mapping] = version
+                if version_lt:
+                    metadata['version_lt'] = version_lt(version)
+                break
+        else:
+            # Bare versions are the same as caret
+            metadata['version_gte'] = version
+            metadata['version_lt'] = _next_caret(version)
+
     return DependencyDescriptor(dependency_name, metadata=metadata)

test/spell_check.words

@@ -47,6 +47,7 @@ tomli
 tomllib
 toprettyxml
 tostring
+unittest
 wildcards
 workspaces
 xmlstr

test/test_package_augmentation.py

@@ -0,0 +1,79 @@
+# Copyright 2026 Open Source Robotics Foundation, Inc.
+# Licensed under the Apache License, Version 2.0
+
+from pathlib import Path
+from unittest.mock import patch
+
+from colcon_cargo.package_augmentation.cargo \
+    import create_dependency_descriptor
+import pytest
+
+
+VERSION_CONSTRAINTS = {
+    None: {},
+    '': {},
+    '1.2.3': {'version_gte': '1.2.3', 'version_lt': '2'},
+    '1.2': {'version_gte': '1.2', 'version_lt': '2'},
+    '1': {'version_gte': '1', 'version_lt': '2'},
+    '0.2.3': {'version_gte': '0.2.3', 'version_lt': '0.3'},
+    '0.2': {'version_gte': '0.2', 'version_lt': '0.3'},
+    '0.0.3': {'version_gte': '0.0.3', 'version_lt': '0.0.4'},
+    '0.0': {'version_gte': '0.0', 'version_lt': '0.1'},
+    '0': {'version_gte': '0', 'version_lt': '1'},
+    '^ 1.2.3': {'version_gte': '1.2.3', 'version_lt': '2'},
+    '^ 1.2': {'version_gte': '1.2', 'version_lt': '2'},
+    '^ 1': {'version_gte': '1', 'version_lt': '2'},
+    '^ 0.2.3': {'version_gte': '0.2.3', 'version_lt': '0.3'},
+    '^ 0.2': {'version_gte': '0.2', 'version_lt': '0.3'},
+    '^ 0.0.3': {'version_gte': '0.0.3', 'version_lt': '0.0.4'},
+    '^ 0.0': {'version_gte': '0.0', 'version_lt': '0.1'},
+    '^ 0': {'version_gte': '0', 'version_lt': '1'},
+    '~ 1.2.3': {'version_gte': '1.2.3', 'version_lt': '1.3'},
+    '~ 1.2': {'version_gte': '1.2', 'version_lt': '1.3'},
+    '~ 1': {'version_gte': '1', 'version_lt': '2'},
+    '*': {'version_gte': '0'},
+    '1.*': {'version_gte': '1', 'version_lt': '2'},
+    '1.2.*': {'version_gte': '1.2', 'version_lt': '1.3'},
+    '>= 1.2.3': {'version_gte': '1.2.3'},
+    '<= 1.2.3': {'version_lte': '1.2.3'},
+    '= 1.2.3': {'version_eq': '1.2.3'},
+    '> 1.2.3': {'version_gt': '1.2.3'},
+    '< 1.2.3': {'version_lt': '1.2.3'},
+    '>1.2.3, <=2.0': {'version_gt': '1.2.3', 'version_lte': '2.0'},
+}
+
+
+@pytest.mark.parametrize('constraints', list(VERSION_CONSTRAINTS.keys()))
+def test_create_dependency_descriptor(constraints):
+    metadata = {
+        'origin': 'cargo',
+        'cargo_source': None,
+        **VERSION_CONSTRAINTS[constraints],
+    }
+
+    dep = create_dependency_descriptor('dependency', constraints, Path.cwd())
+    assert 'dependency' == dep.name
+    assert metadata == dep.metadata
+
+
+@pytest.mark.parametrize('constraints', ['1.*.3', '*.*.3', '*.2'])
+def test_create_dependency_descriptor_unsupported(constraints):
+    metadata = {
+        'origin': 'cargo',
+        'cargo_source': None,
+    }
+
+    with patch(
+        'colcon_cargo.package_augmentation.cargo.logger.warning',
+    ) as log:
+        dep = create_dependency_descriptor(
+            'dependency', constraints, Path.cwd())
+
+    # No constraint in the metadata
+    assert 'dependency' == dep.name
+    assert metadata == dep.metadata
+
+    # Single call to logger.warning()
+    assert log.call_count == 1
+    assert len(log.call_args[0]) >= 1
+    assert 'unsupported' in log.call_args[0][0]