Add in black formatter

Currently this is not enforced in any CI checks yet.

Next step is to apply the formatter fix, and then enforce the format
check after that.

Example usage:

```
// Check with both black and flake8
ramble style

// Only check black
ramble style -t black

// Apply black fix for all relevant files
ramble style -t black -a -f
```

Author: linsword13

lib/ramble/ramble/cmd/style.py

@@ -89,16 +89,13 @@ def is_application(f):
 pattern_exemptions = dict(
     (
         re.compile(file_pattern),
-        dict(
-            (code, [re.compile(p) for p in patterns])
-            for code, patterns in error_dict.items()
-        ),
+        dict((code, [re.compile(p) for p in patterns]) for code, patterns in error_dict.items()),
     )
     for file_pattern, error_dict in pattern_exemptions.items()
 )
 
-
-tool_names = ["flake8"]
+# Tools run in the given order, with flake8 as the last check.
+tool_names = ["black", "flake8"]
 
 tools = {}
 
@@ -221,9 +218,17 @@ def setup_parser(subparser):
         action="append",
         help="specify tools to skip (choose from %s)" % ",".join(tool_names),
     )
-    subparser.add_argument(
-        "files", nargs=argparse.REMAINDER, help="specific files to check"
-    )
+    subparser.add_argument("files", nargs=argparse.REMAINDER, help="specific files to check")
+
+
+def print_tool_header(tool, file_list):
+    print("=======================================================")
+    print(f"{tool}: running {tool} checks on ramble.")
+    print()
+    print("Modified files:")
+    for filename in file_list:
+        print(f"  {filename.strip()}")
+    print("=======================================================")
 
 
 def print_tool_result(tool, returncode):
@@ -241,9 +246,7 @@ def print_output(output, args):
         # print results relative to current working directory
         def cwd_relative(path):
             return "{0}: [".format(
-                os.path.relpath(
-                    os.path.join(ramble.paths.prefix, path.group(1)), os.getcwd()
-                )
+                os.path.relpath(os.path.join(ramble.paths.prefix, path.group(1)), os.getcwd())
             )
 
         for line in output.split("\n"):
@@ -335,13 +338,7 @@ def run_flake8(flake8_cmd, file_list, args):
     temp = tempfile.mkdtemp()
     returncode = 1
     try:
-        print("=======================================================")
-        print("flake8: running flake8 code checks on ramble.")
-        print()
-        print("Modified files:")
-        for filename in file_list:
-            print(f"  {filename.strip()}")
-        print("=======================================================")
+        print_tool_header("flake8", file_list)
 
         # run flake8 on the temporary tree, once for core, once for apps
         application_file_list = [f for f in file_list if is_application(f)]
@@ -413,12 +410,27 @@ def run_flake8(flake8_cmd, file_list, args):
     return returncode
 
 
+@tool("black")
+def run_black(black_cmd, file_list, args):
+    print_tool_header("black", file_list)
+    black_args = ("--config", os.path.join(ramble.paths.prefix, "pyproject.toml"))
+    if not args.fix:
+        black_args += ("--check", "--diff")
+    black_args += tuple(file_list)
+
+    output = black_cmd(*black_args, fail_on_error=False, output=str, error=str)
+    returncode = black_cmd.returncode
+    print_output(output, args)
+    print_tool_result("black", returncode)
+    return returncode
+
+
 def validate_toolset(arg_value):
     """Validate --tool and --skip arguments (sets of optionally comma-separated tools)."""
     tools = set(",".join(arg_value).split(","))  # allow args like 'black,flake8'
     for tool in tools:
         if tool not in tool_names:
-            print(f"Invaild tool: {tool}, choose from: {', '.join(tool_names)}")
+            print(f"Invalid tool: {tool}, choose from: {', '.join(tool_names)}")
     return tools
 
 
@@ -427,9 +439,7 @@ def style(parser, args):
     if file_list:
 
         def prefix_relative(path):
-            return os.path.relpath(
-                os.path.abspath(os.path.realpath(path)), ramble.paths.prefix
-            )
+            return os.path.relpath(os.path.abspath(os.path.realpath(path)), ramble.paths.prefix)
 
         file_list = [prefix_relative(p) for p in file_list]
 
@@ -469,9 +479,7 @@ def prefix_relative(path):
 
         for tool_name in tools_to_run:
             print(f"Running {tool_name} check")
-            returncode |= tools[tool_name](
-                which(tool_name, required=True), file_list, args
-            )
+            returncode |= tools[tool_name](which(tool_name, required=True), file_list, args)
 
     if returncode != 0:
         print("style checks found errors.")

pyproject.toml

@@ -0,0 +1,18 @@
+[tool.black]
+line-length = 99
+target-version = ["py36", "py37", "py38", "py39", "py310", "py311"]
+include = '''
+    \.pyi?$
+'''
+force-exclude = '''
+/(
+    \.git
+  | etc
+  | share
+  | var
+  | lib/ramble/external
+  | lib/ramble/spack
+  | lib/ramble/llnl
+  | __pycache__
+)/
+'''

requirements.txt

@@ -1,5 +1,6 @@
 pytest
 flake8
+black
 google-cloud-storage # for gcs fetch test
 google-api-core # for gcs fetch error .execptions
 coverage

share/ramble/ramble-completion.bash

@@ -267,7 +267,7 @@ _ramble() {
     then
         RAMBLE_COMPREPLY="-h --help -H --all-help --color -c --config -C --config-scope -d --debug --disable-passthrough -N --disable-logger -P --disable-progress-bar --timestamp --pdb -w --workspace -D --workspace-dir -W --no-workspace --use-workspace-repo -k --insecure -l --enable-locks -L --disable-locks -m --mock -p --profile --sorted-profile --lines -v --verbose --stacktrace -V --version --print-shell-vars"
     else
-        RAMBLE_COMPREPLY="attributes clean commands config debug deployment edit flake8 help info license list mirror mods on python repo results software-definitions unit-test workspace"
+        RAMBLE_COMPREPLY="attributes clean commands config debug deployment edit flake8 help info license list mirror mods on python repo results software-definitions style unit-test workspace"
     fi
 }
 
@@ -643,6 +643,15 @@ _ramble_software_definitions() {
     RAMBLE_COMPREPLY="-h --help -s --summary -c --conflicts -e --error-on-conflict"
 }
 
+_ramble_style() {
+    if $list_options
+    then
+        RAMBLE_COMPREPLY="-h --help -b --base -a --all -o --output -r --root-relative -U --no-untracked -f --fix -k --keep-temp -t --tool -s --skip"
+    else
+        RAMBLE_COMREPLY=""
+    fi
+}
+
 _ramble_unit_test() {
     if $list_options
     then