nixos/tests: format the testing-python.nix file more consistenly

nixos/lib/testing-python.nix

@@ -3,11 +3,12 @@
   # Use a minimal kernel?
 , minimal ? false
   # Ignored
-, config ? {}
+, config ? { }
   # !!! See comment about args in lib/modules.nix
-, specialArgs ? {}
+, specialArgs ? { }
   # Modules to add to each VM
-, extraConfigurations ? [] }:
+, extraConfigurations ? [ ]
+}:
 
 with pkgs;
 
@@ -16,9 +17,11 @@ rec {
   inherit pkgs;
 
 
-  mkTestDriver = let
+  mkTestDriver =
+    let
       testDriverScript = ./test-driver/test-driver.py;
-  in qemu_pkg: stdenv.mkDerivation {
+    in
+    qemu_pkg: stdenv.mkDerivation {
       name = "nixos-test-driver";
 
       nativeBuildInputs = [ makeWrapper ];
@@ -75,7 +78,6 @@ rec {
     , skipLint ? false
     , ...
     } @ t:
-
     let
       # A standard store path to the vm monitor is built like this:
       #   /tmp/nix-build-vm-test-run-$name.drv-0/vm-state-machine/monitor
@@ -108,7 +110,8 @@ rec {
           testDriver = mkTestDriver (if qemu_pkg == null then pkgs.qemu_test else qemu_pkg);
 
           nodes = build-vms.buildVirtualNetwork (
-            t.nodes or (if t ? machine then { machine = t.machine; } else { }));
+            t.nodes or (if t ? machine then { machine = t.machine; } else { })
+          );
           vlans = map (m: m.config.virtualisation.vlans) (lib.attrValues nodes);
           vms = map (m: m.config.system.build.vm) (lib.attrValues nodes);
 
@@ -120,7 +123,8 @@ rec {
 
           testDriverName = with builtins;
             if testNameLen > maxTestNameLen then
-              abort ("The name of the test '${name}' must not be longer than ${toString maxTestNameLen} " +
+              abort
+                ("The name of the test '${name}' must not be longer than ${toString maxTestNameLen} " +
                   "it's currently ${toString testNameLen} characters long.")
             else
               "nixos-test-driver-${name}";
@@ -128,7 +132,8 @@ rec {
           warn = if skipLint then lib.warn "Linting is disabled!" else lib.id;
         in
         warn (runCommand testDriverName
-        { buildInputs = [ makeWrapper];
+          {
+            buildInputs = [ makeWrapper ];
             testScript = testScript';
             preferLocalBuild = true;
             testName = name;
@@ -162,7 +167,7 @@ rec {
           ''); # "
 
       passMeta = drv: drv // lib.optionalAttrs (t ? meta) {
-        meta = (drv.meta or {}) // t.meta;
+        meta = (drv.meta or { }) // t.meta;
       };
 
       driver = mkDriver null;
@@ -172,7 +177,8 @@ rec {
 
       nodeNames = builtins.attrNames driver.nodes;
       invalidNodeNames = lib.filter
-        (node: builtins.match "^[A-z_]([A-z0-9_]+)?$" node == null) nodeNames;
+        (node: builtins.match "^[A-z_]([A-z0-9_]+)?$" node == null)
+        nodeNames;
 
     in
     if lib.length invalidNodeNames > 0 then
@@ -202,8 +208,10 @@ rec {
       };
 
       vm = build-vms.buildVM { }
-        [ machine
-          { key = "run-in-machine";
+        [
+          machine
+          {
+            key = "run-in-machine";
             networking.hostName = "client";
             nix.readOnlyStore = false;
             virtualisation.writableStore = false;
@@ -253,13 +261,13 @@ rec {
     lib.overrideDerivation drv (attrs: {
       requiredSystemFeatures = [ "kvm" ];
       builder = "${bash}/bin/sh";
-        args = ["-e" vmRunCommand];
+      args = [ "-e" vmRunCommand ];
       origArgs = attrs.args;
       origBuilder = attrs.builder;
     });
 
 
-  runInMachineWithX = { require ? [], ... } @ args:
+  runInMachineWithX = { require ? [ ], ... } @ args:
     let
       client =
         { ... }: