yarn2nix: change yarnFlags to append by default

The main usecase for this variable is to append --production to yarn
which now got a whole lot easier because you no longer need to repeat
the defaults.

pkgs/applications/editors/uivonim/default.nix

@@ -35,8 +35,6 @@ mkYarnPackage rec {
     name = "uivonim-build-${version}";
     inherit version src packageJSON yarnLock yarnNix yarnPreBuild distPhase;
 
-    yarnFlags = [ "--offline" ];
-
     buildPhase = ''
       yarn build:prod
     '';
@@ -47,7 +45,7 @@ mkYarnPackage rec {
   };
 
   # The --production flag disables the devDependencies.
-  yarnFlags = [ "--offline" "--production" ];
+  yarnFlags = [ "--production" ];
 
   nativeBuildInputs = [ makeWrapper ];
 

pkgs/applications/networking/browsers/vieb/default.nix

@@ -14,7 +14,7 @@ mkYarnPackage rec {
   packageJSON = ./package.json;
   yarnLock = ./yarn.lock;
   yarnNix = ./yarn.nix;
-  yarnFlags = [ "--production" "--offline" ];
+  yarnFlags = [ "--production" ];
 
   nativeBuildInputs = [ makeWrapper ];
 

pkgs/development/tools/yarn2nix-moretea/yarn2nix/default.nix

@@ -69,7 +69,7 @@ in rec {
     yarnLock,
     yarnNix ? mkYarnNix { inherit yarnLock; },
     offlineCache ? importOfflineCache yarnNix,
-    yarnFlags ? defaultYarnFlags,
+    yarnFlags ? [ ],
     pkgConfig ? {},
     preBuild ? "",
     postBuild ? "",
@@ -141,7 +141,7 @@ in rec {
 
         ${workspaceDependencyLinks}
 
-        yarn install ${lib.escapeShellArgs yarnFlags}
+        yarn install ${lib.escapeShellArgs (defaultYarnFlags ++ yarnFlags)}
 
         ${lib.concatStringsSep "\n" postInstall}
 
@@ -241,7 +241,7 @@ in rec {
     yarnLock ? src + "/yarn.lock",
     yarnNix ? mkYarnNix { inherit yarnLock; },
     offlineCache ? importOfflineCache yarnNix,
-    yarnFlags ? defaultYarnFlags,
+    yarnFlags ? [ ],
     yarnPreBuild ? "",
     yarnPostBuild ? "",
     pkgConfig ? {},

pkgs/tools/misc/sharedown/default.nix

@@ -55,9 +55,7 @@ stdenvNoCC.mkDerivation rec {
         name = "${pname}-modules-${version}";
         inherit pname version;
 
-        yarnFlags = yarn2nix-moretea.defaultYarnFlags ++ [
-          "--production"
-        ];
+        yarnFlags = [ "--production" ];
 
         pkgConfig = {
           keytar = {