SCons: Format buildsystem files with psf/black

Configured for a max line length of 120 characters.

psf/black is very opinionated and purposely doesn't leave much room for
configuration. The output is mostly OK so that should be fine for us,
but some things worth noting:

- Manually wrapped strings will be reflowed, so by using a line length
  of 120 for the sake of preserving readability for our long command
  calls, it also means that some manually wrapped strings are back on
  the same line and should be manually merged again.

- Code generators using string concatenation extensively look awful,
  since black puts each operand on a single line. We need to refactor
  these generators to use more pythonic string formatting, for which
  many options are available (`%`, `format` or f-strings).

- CI checks and a pre-commit hook will be added to ensure that future
  buildsystem changes are well-formatted.

3 files changed, 9 insertions, 7 deletions

diff --git a/main/SCsub b/main/SCsub
index 0262701d79..7a301b82bc 100644
--- a/main/SCsub
+++ b/main/SCsub
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 
-Import('env')
+Import("env")
 
 from platform_methods import run_in_subprocess
 import main_builders
@@ -14,13 +14,15 @@ env.Depends("#main/splash.gen.h", "#main/splash.png")
 env.CommandNoCache("#main/splash.gen.h", "#main/splash.png", run_in_subprocess(main_builders.make_splash))
 
 env.Depends("#main/splash_editor.gen.h", "#main/splash_editor.png")
-env.CommandNoCache("#main/splash_editor.gen.h", "#main/splash_editor.png", run_in_subprocess(main_builders.make_splash_editor))
+env.CommandNoCache(
+    "#main/splash_editor.gen.h", "#main/splash_editor.png", run_in_subprocess(main_builders.make_splash_editor)
+)
 
 env.Depends("#main/app_icon.gen.h", "#main/app_icon.png")
 env.CommandNoCache("#main/app_icon.gen.h", "#main/app_icon.png", run_in_subprocess(main_builders.make_app_icon))
 
 if env["tools"]:
-    SConscript('tests/SCsub')
+    SConscript("tests/SCsub")
 
 lib = env.add_library("main", env.main_sources)
 env.Prepend(LIBS=[lib])
diff --git a/main/main_builders.py b/main/main_builders.py
index aebac2b022..2ea774e3b4 100644
--- a/main/main_builders.py
+++ b/main/main_builders.py
@@ -18,7 +18,7 @@ def make_splash(target, source, env):
         g.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
         g.write("#ifndef BOOT_SPLASH_H\n")
         g.write("#define BOOT_SPLASH_H\n")
-        g.write('static const Color boot_splash_bg_color = Color(0.14, 0.14, 0.14);\n')
+        g.write("static const Color boot_splash_bg_color = Color(0.14, 0.14, 0.14);\n")
         g.write("static const unsigned char boot_splash_png[] = {\n")
         for i in range(len(buf)):
             g.write(str(buf[i]) + ",\n")
@@ -37,7 +37,7 @@ def make_splash_editor(target, source, env):
         g.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
         g.write("#ifndef BOOT_SPLASH_EDITOR_H\n")
         g.write("#define BOOT_SPLASH_EDITOR_H\n")
-        g.write('static const Color boot_splash_editor_bg_color = Color(0.14, 0.14, 0.14);\n')
+        g.write("static const Color boot_splash_editor_bg_color = Color(0.14, 0.14, 0.14);\n")
         g.write("static const unsigned char boot_splash_editor_png[] = {\n")
         for i in range(len(buf)):
             g.write(str(buf[i]) + ",\n")
@@ -63,5 +63,5 @@ def make_app_icon(target, source, env):
         g.write("#endif")
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     subprocess_main(globals())
diff --git a/main/tests/SCsub b/main/tests/SCsub
index 437d9ed777..cb1d35b12f 100644
--- a/main/tests/SCsub
+++ b/main/tests/SCsub
@@ -1,6 +1,6 @@
 #!/usr/bin/python
 
-Import('env')
+Import("env")
 
 env.tests_sources = []
 env.add_source_files(env.tests_sources, "*.cpp")