Introduce `default_args` context manager (#39964)

This adds a rather trivial context manager that lets you deduplicate repeated
arguments in directives, e.g.

```python
depends_on("py-x@1", when="@1", type=("build", "run"))
depends_on("py-x@2", when="@2", type=("build", "run"))
depends_on("py-x@3", when="@3", type=("build", "run"))
depends_on("py-x@4", when="@4", type=("build", "run"))
```

can be condensed to

```python
with default_args(type=("build", "run")):
    depends_on("py-x@1", when="@1")
    depends_on("py-x@2", when="@2")
    depends_on("py-x@3", when="@3")
    depends_on("py-x@4", when="@4")
```

The advantage is it's clear for humans, the downside it's less clear for type checkers due to type erasure.

1 files changed, 18 insertions, 17 deletions

diff --git a/var/spack/repos/builtin/packages/py-black/package.py b/var/spack/repos/builtin/packages/py-black/package.py
index bb6539d715..825d37a446 100644
--- a/var/spack/repos/builtin/packages/py-black/package.py
+++ b/var/spack/repos/builtin/packages/py-black/package.py
@@ -37,23 +37,24 @@ class PyBlack(PythonPackage):
     depends_on("py-hatchling@1.8:", when="@22.10:", type="build")
     depends_on("py-hatch-vcs", when="@22.10:", type="build")
     depends_on("py-hatch-fancy-pypi-readme", when="@22.10:", type="build")
-    depends_on("python@3.8:", when="@23.7:", type=("build", "run"))
-    # Needed to ensure that Spack can bootstrap black with Python 3.6
-    depends_on("python@3.7:", when="@22.10:", type=("build", "run"))
-    depends_on("py-click@8:", type=("build", "run"))
-    depends_on("py-mypy-extensions@0.4.3:", type=("build", "run"))
-    depends_on("py-packaging@22:", when="@23.1:", type=("build", "run"))
-    depends_on("py-pathspec@0.9:", type=("build", "run"))
-    depends_on("py-platformdirs@2:", type=("build", "run"))
-    depends_on("py-tomli@1.1:", when="@22.8: ^python@:3.10", type=("build", "run"))
-    depends_on("py-tomli@1.1:", when="@21.7:22.6", type=("build", "run"))
-    depends_on("py-typing-extensions@3.10:", when="^python@:3.9", type=("build", "run"))
-
-    depends_on("py-colorama@0.4.3:", when="+colorama", type=("build", "run"))
-    depends_on("py-uvloop@0.15.2:", when="+uvloop", type=("build", "run"))
-    depends_on("py-aiohttp@3.7.4:", when="+d", type=("build", "run"))
-    depends_on("py-ipython@7.8:", when="+jupyter", type=("build", "run"))
-    depends_on("py-tokenize-rt@3.2:", when="+jupyter", type=("build", "run"))
+
+    with default_args(type=("build", "run")):
+        depends_on("python@3.8:", when="@23.7:")
+        depends_on("python@3.7:", when="@22.10:")
+        depends_on("py-click@8:")
+        depends_on("py-mypy-extensions@0.4.3:")
+        depends_on("py-packaging@22:", when="@23.1:")
+        depends_on("py-pathspec@0.9:")
+        depends_on("py-platformdirs@2:")
+        depends_on("py-tomli@1.1:", when="@22.8: ^python@:3.10")
+        depends_on("py-tomli@1.1:", when="@21.7:22.6")
+        depends_on("py-typing-extensions@3.10:", when="^python@:3.9")
+
+    depends_on("py-colorama@0.4.3:", when="+colorama")
+    depends_on("py-uvloop@0.15.2:", when="+uvloop")
+    depends_on("py-aiohttp@3.7.4:", when="+d")
+    depends_on("py-ipython@7.8:", when="+jupyter")
+    depends_on("py-tokenize-rt@3.2:", when="+jupyter")
 
     # Historical dependencies
     depends_on("py-setuptools@45:", when="@:22.8", type=("build", "run"))