From 2aec0c89fda0612d4b239b72a5372dc75f9c7beb Mon Sep 17 00:00:00 2001
From: phaer <hello@phaer.org>
Date: Tue, 23 Jul 2024 13:57:51 +0200
Subject: [PATCH] lock: expose lock.isValid...

this is useful to figure out which lock scripts to run
in package collections.
---
 modules/dream2nix/core/lock/default.nix   | 4 +++-
 modules/dream2nix/core/lock/interface.nix | 8 ++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/modules/dream2nix/core/lock/default.nix b/modules/dream2nix/core/lock/default.nix
index ba2ea0cece..be5422795a 100644
--- a/modules/dream2nix/core/lock/default.nix
+++ b/modules/dream2nix/core/lock/default.nix
@@ -18,6 +18,7 @@
 
   invalidationHashCurrent = l.hashString "sha256" (l.toJSON cfg.invalidationData);
   invalidationHashLocked = fileContent.invalidationHash or null;
+  isValid = invalidationHashCurrent == invalidationHashLocked;
 
   # script to remove the lock file if no fields are defined
   removeLockFileScript = config.deps.writePython3Bin "refresh" {} ''
@@ -182,7 +183,7 @@
     else throw (errorOutdatedField field);
 
   loadedContent =
-    if invalidationHashCurrent != invalidationHashLocked
+    if !isValid
     then throw errorOutdated
     else l.mapAttrs loadField cfg.fields;
 
@@ -217,6 +218,7 @@ in {
 
     lock.content = mkLazy loadedContent;
 
+    lock.isValid = isValid;
     lock.lib = {inherit computeFODHash;};
 
     deps = {nixpkgs, ...}:
diff --git a/modules/dream2nix/core/lock/interface.nix b/modules/dream2nix/core/lock/interface.nix
index 02423f8a19..462f4384ca 100644
--- a/modules/dream2nix/core/lock/interface.nix
+++ b/modules/dream2nix/core/lock/interface.nix
@@ -83,6 +83,14 @@ in {
       readOnly = true;
     };
 
+    isValid = l.mkOption {
+      type = t.bool;
+      description = ''
+        Check whether the current lock file is valid, which means we don't need to lock again.
+      '';
+      readOnly = true;
+    };
+
     lib.computeFODHash = l.mkOption {
       type = t.functionTo t.path;
       description = ''