pkgs-lib: Add tests for formats

pkgs/pkgs-lib/tests/default.nix

@@ -1,5 +1,7 @@
 # Call nix-build on this file to run all tests in this directory
 { pkgs ? import ../../.. {} }:
 let
+  formats = import ./formats.nix { inherit pkgs; };
 in pkgs.linkFarm "nixpkgs-pkgs-lib-tests" [
+  { name = "formats"; path = import ./formats.nix { inherit pkgs; }; }
 ]

pkgs/pkgs-lib/tests/formats.nix

@@ -0,0 +1,157 @@
+{ pkgs }:
+let
+  inherit (pkgs) lib formats;
+in
+with lib;
+let
+
+  evalFormat = format: args: def:
+    let
+      formatSet = format args;
+      config = formatSet.type.merge [] (imap1 (n: def: {
+        value = def;
+        file = "def${toString n}";
+      }) [ def ]);
+    in formatSet.generate "test-format-file" config;
+
+  runBuildTest = name: { drv, expected }: pkgs.runCommandNoCC name {} ''
+    if diff ${drv} ${builtins.toFile "expected" expected}; then
+      touch $out
+    else
+      echo "Got: $(cat ${drv})"
+      echo "Should be: ${expected}"
+      exit 1
+    fi
+  '';
+
+  runBuildTests = tests: pkgs.linkFarm "nixpkgs-pkgs-lib-format-tests" (mapAttrsToList (name: value: { inherit name; path = runBuildTest name value; }) (filterAttrs (name: value: value != null) tests));
+
+in runBuildTests {
+
+  testJsonAtoms = {
+    drv = evalFormat formats.json {} {
+      null = null;
+      false = false;
+      true = true;
+      int = 10;
+      float = 3.141;
+      str = "foo";
+      attrs.foo = null;
+      list = [ null null ];
+    };
+    expected = ''
+      {
+        "attrs": {
+          "foo": null
+        },
+        "false": false,
+        "float": 3.141,
+        "int": 10,
+        "list": [
+          null,
+          null
+        ],
+        "null": null,
+        "str": "foo",
+        "true": true
+      }
+    '';
+  };
+
+  testYamlAtoms = {
+    drv = evalFormat formats.yaml {} {
+      null = null;
+      false = false;
+      true = true;
+      float = 3.141;
+      str = "foo";
+      attrs.foo = null;
+      list = [ null null ];
+    };
+    expected = ''
+      {
+        "attrs": {
+          "foo": null
+        },
+        "false": false,
+        "float": 3.141,
+        "list": [
+          null,
+          null
+        ],
+        "null": null,
+        "str": "foo",
+        "true": true
+      }
+    '';
+  };
+
+  testIniAtoms = {
+    drv = evalFormat formats.ini {} {
+      foo = {
+        bool = true;
+        int = 10;
+        float = 3.141;
+        str = "string";
+      };
+    };
+    expected = ''
+      [foo]
+      bool=true
+      float=3.141000
+      int=10
+      str=string
+    '';
+  };
+
+  testIniDuplicateKeys = {
+    drv = evalFormat formats.ini { listsAsDuplicateKeys = true; } {
+      foo = {
+        bar = [ null true "test" 1.2 10 ];
+        baz = false;
+        qux = "qux";
+      };
+    };
+    expected = ''
+      [foo]
+      bar=null
+      bar=true
+      bar=test
+      bar=1.200000
+      bar=10
+      baz=false
+      qux=qux
+    '';
+  };
+
+  testTomlAtoms = {
+    drv = evalFormat formats.toml {} {
+      false = false;
+      true = true;
+      int = 10;
+      float = 3.141;
+      str = "foo";
+      attrs.foo = "foo";
+      list = [ 1 2 ];
+      level1.level2.level3.level4 = "deep";
+    };
+    expected = ''
+      false = false
+      float = 3.141
+      int = 10
+      list = [1, 2]
+      str = "foo"
+      true = true
+
+      [attrs]
+      foo = "foo"
+
+      [level1]
+
+      [level1.level2]
+
+      [level1.level2.level3]
+      level4 = "deep"
+    '';
+  };
+}