From 32c7a5e0469e220b716188d4cc16aff7f143a7d1 Mon Sep 17 00:00:00 2001
From: phaer <hello@phaer.org>
Date: Wed, 22 Apr 2026 11:49:31 +0200
Subject: [PATCH 1/3] pkgs-lib/formats: add regression tests for toml generator

Add two shouldPass tests that catch known yj regressions:

- tomlHeterogeneousArray: arrays mixing scalars and attrsets crash yj
  with 'unexpected primitive type' (NixOS/nixpkgs#511970)

- tomlCommaInKey: keys containing commas are silently truncated
  because yj stores TOML keys in Go struct tags where commas are
  option separators (sclevine/yj#52)

Expected values are taken from go-toml's jsontoml output.
Both tests fail under the current yj backend.
---
 pkgs/pkgs-lib/tests/formats.nix | 35 +++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/pkgs/pkgs-lib/tests/formats.nix b/pkgs/pkgs-lib/tests/formats.nix
index d51b5d2f272b..40c096bd88f7 100644
--- a/pkgs/pkgs-lib/tests/formats.nix
+++ b/pkgs/pkgs-lib/tests/formats.nix
@@ -708,6 +708,41 @@ runBuildTests {
     '';
   };
 
+  # Regression test for https://github.com/NixOS/nixpkgs/issues/511970
+  # yj crashes on arrays mixing scalars and attrsets (heterogeneous arrays),
+  # e.g. Helix language-server configs like ["bash-ls", {name = "ts-ls"; ...}].
+  # TOML 1.0 allows mixed-type arrays; the converter must emit them as
+  # inline arrays with inline tables.
+  tomlHeterogeneousArray = shouldPass {
+    format = formats.toml { };
+    input = {
+      language-server = [
+        "bash-language-server"
+        {
+          name = "typescript-language-server";
+          except-features = [ "diagnostics" ];
+        }
+      ];
+    };
+    expected = ''
+      language-server = ['bash-language-server', {except-features = ['diagnostics'], name = 'typescript-language-server'}]
+    '';
+  };
+
+  # Regression test for https://github.com/sclevine/yj/issues/52
+  # yj truncates keys at the first comma because it stores TOML keys in Go
+  # struct tags, where commas are option separators.
+  # e.g. "stack(x,n)" is emitted as "stack(x" — silently losing data.
+  tomlCommaInKey = shouldPass {
+    format = formats.toml { };
+    input = {
+      "stack(x,n)" = "foobar";
+    };
+    expected = ''
+      'stack(x,n)' = 'foobar'
+    '';
+  };
+
   cdnAtoms = shouldPass {
     format = formats.cdn { };
     input = {

From d5551849a5cc759afc706f87feef4a3f28d3ac6a Mon Sep 17 00:00:00 2001
From: phaer <hello@phaer.org>
Date: Wed, 22 Apr 2026 11:49:32 +0200
Subject: [PATCH 2/3] go-toml: drop erroneous allowGoReference

allowGoReference was added in 5a69b0b3c4a (2024-04-29) with the
comment 'allowGoReference adds the flag -trimpath'.  This is
backwards: allowGoReference = true *disables* -trimpath and *allows*
the Go compiler to remain in the runtime closure (257 MiB).

The package builds and passes all tests without it.  Dropping it
re-enables -trimpath and shrinks the runtime closure from 263.6 MiB
to 8.6 MiB.
---
 pkgs/by-name/go/go-toml/package.nix | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/pkgs/by-name/go/go-toml/package.nix b/pkgs/by-name/go/go-toml/package.nix
index e18ac104f70d..5ea5e58c51ea 100644
--- a/pkgs/by-name/go/go-toml/package.nix
+++ b/pkgs/by-name/go/go-toml/package.nix
@@ -25,10 +25,6 @@ buildGoModule {
     "cmd/tomltestgen"
   ];
 
-  # allowGoReference adds the flag `-trimpath` which is also denoted by, go-toml's goreleaser config
-  #  <https://github.com/pelletier/go-toml/blob/a3d5a0bb530b5206c728eed9cb57323061922bcb/.goreleaser.yaml#L13>
-  allowGoReference = true;
-
   ldflags = [
     "-s"
     "-w"

From e23ad3bd2739af8ac41d5338fb389029f551cde9 Mon Sep 17 00:00:00 2001
From: phaer <hello@phaer.org>
Date: Wed, 22 Apr 2026 11:49:33 +0200
Subject: [PATCH 3/3] pkgs-lib/formats: switch toml generator from yj to
 go-toml (jsontoml)

Fixes NixOS/nixpkgs#511970, sclevine/yj#52.

Replace yj with go-toml's jsontoml for JSON-to-TOML conversion.
Update tomlAtoms expected output for go-toml's literal-string style.
---
 pkgs/pkgs-lib/formats.nix       | 8 +++++---
 pkgs/pkgs-lib/tests/formats.nix | 6 +++---
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/pkgs/pkgs-lib/formats.nix b/pkgs/pkgs-lib/formats.nix
index 9478a11f83f6..0e0c9368fab1 100644
--- a/pkgs/pkgs-lib/formats.nix
+++ b/pkgs/pkgs-lib/formats.nix
@@ -461,16 +461,18 @@ optionalAttrs allowAliases aliases
       generate =
         name: value:
         pkgs.callPackage (
-          { runCommand, yj }:
+          { runCommand, go-toml }:
           runCommand name
             {
-              nativeBuildInputs = [ yj ];
+              nativeBuildInputs = [ go-toml ];
               value = builtins.toJSON value;
               passAsFile = [ "value" ];
               preferLocalBuild = true;
             }
+            # -use-json-number: preserve JSON ints as TOML ints
+            # (Go's json.Decoder defaults to float64 for all numbers)
             ''
-              yj -jt < "$valuePath" > "$out"
+              jsontoml -use-json-number < "$valuePath" > "$out"
             ''
         ) { };
 
diff --git a/pkgs/pkgs-lib/tests/formats.nix b/pkgs/pkgs-lib/tests/formats.nix
index 40c096bd88f7..49b9ac4c8a30 100644
--- a/pkgs/pkgs-lib/tests/formats.nix
+++ b/pkgs/pkgs-lib/tests/formats.nix
@@ -695,16 +695,16 @@ runBuildTests {
       float = 3.141
       int = 10
       list = [1, 2]
-      str = "foo"
+      str = 'foo'
       true = true
 
       [attrs]
-      foo = "foo"
+      foo = 'foo'
 
       [level1]
       [level1.level2]
       [level1.level2.level3]
-      level4 = "deep"
+      level4 = 'deep'
     '';
   };