|
| 1 | +import grimp |
| 2 | +import grimp.application |
| 3 | +import grimp.application.config |
| 4 | +import grimp.exceptions |
| 5 | +from pydantic import BaseModel |
| 6 | + |
| 7 | +from usethis._integrations.project.errors import ImportGraphBuildFailedError |
| 8 | + |
| 9 | + |
| 10 | +class LayeredArchitecture(BaseModel): |
| 11 | + layers: list[set[str]] |
| 12 | + excluded: set[str] = set() |
| 13 | + |
| 14 | + |
| 15 | +def get_layered_architectures(pkg_name: str) -> dict[str, LayeredArchitecture]: |
| 16 | + """Get the suggested layers for a package. |
| 17 | +
|
| 18 | + This is intended to inform the basis of a layer contract. |
| 19 | +
|
| 20 | + Reference: |
| 21 | + https://import-linter.readthedocs.io/en/stable/contract_types.html#layers |
| 22 | +
|
| 23 | + Args: |
| 24 | + pkg_name: The name of the package. |
| 25 | +
|
| 26 | + Returns: |
| 27 | + A dictionary mapping module names to their layered architecture. |
| 28 | + """ |
| 29 | + graph = _get_graph(pkg_name) |
| 30 | + |
| 31 | + arch_by_module = {} |
| 32 | + |
| 33 | + for module in graph.modules: |
| 34 | + arch = _get_module_layered_architecture(module, graph=graph) |
| 35 | + if len(arch.layers) > 1: |
| 36 | + arch_by_module[module] = arch |
| 37 | + |
| 38 | + return arch_by_module |
| 39 | + |
| 40 | + |
| 41 | +def _get_module_layered_architecture( |
| 42 | + module: str, *, graph: grimp.ImportGraph |
| 43 | +) -> LayeredArchitecture: |
| 44 | + deps_by_module = _get_child_dependencies(module, graph=graph) |
| 45 | + |
| 46 | + layered = set() |
| 47 | + layers = [] |
| 48 | + |
| 49 | + for _ in range(len(deps_by_module)): |
| 50 | + # Form a layer: cycle through all siblings. For ones with no deps, add them |
| 51 | + # to the layer and ignore them in the next iteration. |
| 52 | + |
| 53 | + layer = set() |
| 54 | + for m, deps in deps_by_module.items(): |
| 55 | + if m in layered: |
| 56 | + continue |
| 57 | + |
| 58 | + unlayered_deps = deps - layered - {m} |
| 59 | + if not unlayered_deps: |
| 60 | + layer.add(m) |
| 61 | + |
| 62 | + if not layer: |
| 63 | + break |
| 64 | + |
| 65 | + layers.append(layer) |
| 66 | + layered.update(layer) |
| 67 | + |
| 68 | + excluded = set() |
| 69 | + for m in deps_by_module: |
| 70 | + if m not in layered: |
| 71 | + excluded.add(m) |
| 72 | + |
| 73 | + return LayeredArchitecture( |
| 74 | + layers=list(reversed(layers)), |
| 75 | + excluded=excluded, |
| 76 | + ) |
| 77 | + |
| 78 | + |
| 79 | +def _get_child_dependencies( |
| 80 | + module: str, *, graph: grimp.ImportGraph |
| 81 | +) -> dict[str, set[str]]: |
| 82 | + """For each child submodule, give a set of the sibling submodules it depends on. |
| 83 | +
|
| 84 | + For example, let's say we have `c` which depends on `a`, and `b` depends on `a`. |
| 85 | + `a` does not depend on anything, and `c` depends on `a` through `b`. Then the |
| 86 | + function will return: |
| 87 | +
|
| 88 | + ``` |
| 89 | + { |
| 90 | + "a": set(), |
| 91 | + "b": {"a"}, |
| 92 | + "c": {"a", "b"}, |
| 93 | + } |
| 94 | + ``` |
| 95 | + """ |
| 96 | + children = sorted(graph.find_children(module)) |
| 97 | + |
| 98 | + deps_by_module = {} |
| 99 | + for child in children: |
| 100 | + downstreams = graph.find_upstream_modules(module=child, as_package=True) |
| 101 | + downstreams = _filter_to_submodule(downstreams, submodule=module) |
| 102 | + |
| 103 | + deps_by_module[_narrow_to_submodule(child, submodule=module)] = downstreams |
| 104 | + |
| 105 | + return deps_by_module |
| 106 | + |
| 107 | + |
| 108 | +def _filter_to_submodule(modules: set[str], *, submodule: str) -> set[str]: |
| 109 | + filtered = set() |
| 110 | + for module in modules: |
| 111 | + if module.startswith(submodule + "."): |
| 112 | + filtered.add(_narrow_to_submodule(module, submodule=submodule)) |
| 113 | + |
| 114 | + return filtered |
| 115 | + |
| 116 | + |
| 117 | +def _narrow_to_submodule(module: str, *, submodule: str) -> str: |
| 118 | + return module.removeprefix(submodule + ".").split(".")[0] |
| 119 | + |
| 120 | + |
| 121 | +def _get_graph(pkg_name: str) -> grimp.ImportGraph: |
| 122 | + try: |
| 123 | + graph = grimp.build_graph(pkg_name, cache_dir=None) |
| 124 | + except ValueError as err: |
| 125 | + raise ImportGraphBuildFailedError(err) from None |
| 126 | + except ModuleNotFoundError as err: |
| 127 | + raise ImportGraphBuildFailedError(err) from None |
| 128 | + except grimp.exceptions.NotATopLevelModule: |
| 129 | + msg = f"Module {pkg_name} is not a top-level module, cannot build graph." |
| 130 | + raise ImportGraphBuildFailedError(msg) from None |
| 131 | + |
| 132 | + return graph |
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