tests.stdenv: add test-golden-example-structuredAttrs

examples copied from https://nixos.mayflower.consulting/blog/2020/01/20/structured-attrs/

nix has tests for structuredAttrs but i figured it'd be good to have a
golden test here too

https://github.com/NixOS/nix/blob/master/tests/structured-attrs.nix
https://github.com/NixOS/nix/blob/master/tests/structured-attrs-shell.nix

pkgs/test/stdenv/default.nix

@@ -8,6 +8,8 @@
 }:
 
 let
+  # early enough not to rebuild gcc but late enough to have patchelf
+  earlyPkgs = stdenv.__bootPackages.stdenv.__bootPackages;
   # use a early stdenv so when hacking on stdenv this test can be run quickly
   bootStdenv = stdenv.__bootPackages.stdenv.__bootPackages.stdenv.__bootPackages.stdenv.__bootPackages.stdenv;
   pkgsStructured = import pkgs.path { config = { structuredAttrsByDefault = true; }; inherit (stdenv.hostPlatform) system; };
@@ -155,5 +157,74 @@ in
         '';
       };
     };
+
+    test-golden-example-structuredAttrs =
+      let
+        goldenSh = earlyPkgs.writeText "goldenSh" ''
+          declare -A EXAMPLE_ATTRS=(['foo']='bar' )
+          declare EXAMPLE_BOOL_FALSE=
+          declare EXAMPLE_BOOL_TRUE=1
+          declare EXAMPLE_INT=123
+          declare EXAMPLE_INT_NEG=-123
+          declare -a EXAMPLE_LIST=('foo' 'bar' )
+          declare EXAMPLE_STR='foo bar'
+        '';
+        goldenJson = earlyPkgs.writeText "goldenSh" ''
+          {
+            "EXAMPLE_ATTRS": {
+              "foo": "bar"
+            },
+            "EXAMPLE_BOOL_FALSE": false,
+            "EXAMPLE_BOOL_TRUE": true,
+            "EXAMPLE_INT": 123,
+            "EXAMPLE_INT_NEG": -123,
+            "EXAMPLE_LIST": [
+              "foo",
+              "bar"
+            ],
+            "EXAMPLE_NESTED_ATTRS": {
+              "foo": {
+                "bar": "baz"
+              }
+            },
+            "EXAMPLE_NESTED_LIST": [
+              [
+                "foo",
+                "bar"
+              ],
+              [
+                "baz"
+              ]
+            ],
+            "EXAMPLE_STR": "foo bar"
+          }
+        '';
+      in
+      bootStdenvStructuredAttrsByDefault.mkDerivation {
+        name = "test-golden-example-structuredAttrsByDefault";
+        nativeBuildInputs = [ earlyPkgs.jq ];
+
+        EXAMPLE_BOOL_TRUE = true;
+        EXAMPLE_BOOL_FALSE = false;
+        EXAMPLE_INT = 123;
+        EXAMPLE_INT_NEG = -123;
+        EXAMPLE_STR = "foo bar";
+        EXAMPLE_LIST = [ "foo" "bar" ];
+        EXAMPLE_NESTED_LIST = [ [ "foo" "bar" ] [ "baz" ] ];
+        EXAMPLE_ATTRS = { foo = "bar"; };
+        EXAMPLE_NESTED_ATTRS = { foo.bar = "baz"; };
+
+        inherit goldenSh;
+        inherit goldenJson;
+
+        buildCommand = ''
+          mkdir -p $out
+          cat $NIX_ATTRS_SH_FILE | grep "EXAMPLE" | grep -v -E 'installPhase|jq' > $out/sh
+          jq 'with_entries(select(.key|match("EXAMPLE")))' $NIX_ATTRS_JSON_FILE > $out/json
+          diff $out/sh $goldenSh
+          diff $out/json $goldenJson
+        '';
+      };
+
   };
 }