Add config support to find_opts

invocations/checks.py

@@ -33,24 +33,28 @@ def blacken(
     :param str find_opts:
         Extra option string appended to the end of the internal ``find``
         command. For example, skip a vendor directory with ``"-and -not -path
-        ./vendor\*"``, add ``-mtime N``, or etc.
+        ./vendor\*"``, add ``-mtime N``, or etc. Honors the
+        ``blacken.find_opts`` config option.
 
     .. versionadded:: 1.2
     .. versionchanged:: 1.4
         Added the ``find_opts`` argument.
     """
+    config = c.config.get("blacken", {})
     default_folders = ["."]
-    configured_folders = c.config.get("blacken", {}).get(
-        "folders", default_folders
-    )
+    configured_folders = config.get("folders", default_folders)
     folders = folders or configured_folders
 
+    default_find_opts = ""
+    configured_find_opts = config.get("find_opts", default_find_opts)
+    find_opts = find_opts or configured_find_opts
+
     black_command_line = "black -l {}".format(line_length)
     if check:
         black_command_line = "{} --check".format(black_command_line)
     if diff:
         black_command_line = "{} --diff".format(black_command_line)
-    if find_opts is not None:
+    if find_opts:
         find_opts = " {}".format(find_opts)
     else:
         find_opts = ""

tests/checks.py

@@ -72,3 +72,15 @@ def folders_config_loses_to_runtime(self, ctx):
             ctx.blacken = dict(folders=["nowhere"])
             blacken(ctx, folders=["nowhere"])
             assert "nowhere" in ctx.run_command
+
+        def find_opts_configurable(self, ctx):
+            ctx.blacken = dict(find_opts="-and -not -name foo.py")
+            blacken(ctx)
+            assert (
+                "find . -name '*.py' -and -not -name foo.py" in ctx.run_command
+            )
+
+        def find_opts_config_loses_to_runtime(self, ctx):
+            ctx.blacken = dict(find_opts="-and -not -name foo.py")
+            blacken(ctx, find_opts="-or -name '*.js'")
+            assert "find . -name '*.py' -or -name '*.js'" in ctx.run_command