Merge pull request #284551 from hercules-ci/types-attrTag

Add `types.attrTag`

lib/default.nix

@@ -128,7 +128,7 @@ let
  canCleanSource pathIsGitRepo;
  inherit (self.modules) evalModules setDefaultModuleLocation
  unifyModuleSyntax applyModuleArgsIfFunction mergeModules
- mergeModules' mergeOptionDecls evalOptionValue mergeDefinitions
+ mergeModules' mergeOptionDecls mergeDefinitions
  pushDownProperties dischargeProperties filterOverrides
  sortProperties fixupOptionType mkIf mkAssert mkMerge mkOverride
  mkOptionDefault mkDefault mkImageMediaOverride mkForce mkVMOverride
@@ -138,6 +138,7 @@ let
  mkMergedOptionModule mkChangedOptionModule
  mkAliasOptionModule mkDerivedConfig doRename
  mkAliasOptionModuleMD;
+ evalOptionValue = lib.warn "External use of `lib.evalOptionValue` is deprecated. If your use case isn't covered by non-deprecated functions, we'd like to know more and perhaps support your use case well, instead of providing access to these low level functions. In this case please open an issue in https://github.com/nixos/nixpkgs/issues/." self.modules.evalOptionValue;
  inherit (self.options) isOption mkEnableOption mkSinkUndeclaredOptions
  mergeDefaultOption mergeOneOption mergeEqualOption mergeUniqueOption
  getValues getFiles

lib/modules.nix

@@ -1378,7 +1378,6 @@ let
  inherit
  applyModuleArgsIfFunction
  dischargeProperties
- evalOptionValue
  mergeModules
  mergeModules'
  pushDownProperties
@@ -1399,6 +1398,7 @@ private //
  defaultPriority
  doRename
  evalModules
+ evalOptionValue # for use by lib.types
  filterOverrides
  filterOverrides'
  fixMergeModules

lib/tests/modules.sh

@@ -103,6 +103,18 @@ checkConfigError 'The option .sub.wrong2. does not exist. Definition values:' co
 checkConfigError '.*This can happen if you e.g. declared your options in .types.submodule.' config.sub ./error-mkOption-in-submodule-config.nix
 checkConfigError '.*A definition for option .bad. is not of type .non-empty .list of .submodule...\.' config.bad ./error-nonEmptyListOf-submodule.nix
 
+# types.attrTag
+checkConfigOutput '^true$' config.okChecks ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.syntaxError. is not of type .attribute-tagged union' config.intStrings.syntaxError ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.syntaxError2. is not of type .attribute-tagged union' config.intStrings.syntaxError2 ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.syntaxError3. is not of type .attribute-tagged union' config.intStrings.syntaxError3 ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.syntaxError4. is not of type .attribute-tagged union' config.intStrings.syntaxError4 ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.mergeError. is not of type .attribute-tagged union' config.intStrings.mergeError ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.badTagError. is not of type .attribute-tagged union' config.intStrings.badTagError ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.badTagTypeError\.left. is not of type .signed integer.' config.intStrings.badTagTypeError.left ./types-attrTag.nix
+checkConfigError 'A definition for option .nested\.right\.left. is not of type .signed integer.' config.nested.right.left ./types-attrTag.nix
+checkConfigError 'In attrTag, each tag value must be an option, but tag int was a bare type, not wrapped in mkOption.' config.opt.int ./types-attrTag-wrong-decl.nix
+
 # types.pathInStore
 checkConfigOutput '".*/store/0lz9p8xhf89kb1c1kk6jxrzskaiygnlh-bash-5.2-p15.drv"' config.pathInStore.ok1 ./types.nix
 checkConfigOutput '".*/store/0fb3ykw9r5hpayd05sr0cizwadzq1d8q-bash-5.2-p15"' config.pathInStore.ok2 ./types.nix

lib/tests/modules/docs.nix

@@ -0,0 +1,41 @@
+/*
+ A basic documentation generating module.
+ Declares and defines a `docs` option, suitable for making assertions about
+ the extraction "phase" of documentation generation.
+ */
+{ lib, options, ... }:
+
+let
+ inherit (lib)
+ head
+ length
+ mkOption
+ types
+ ;
+
+ traceListSeq = l: v: lib.foldl' (a: b: lib.traceSeq b a) v l;
+
+in
+
+{
+ options.docs = mkOption {
+ type = types.lazyAttrsOf types.raw;
+ description = ''
+ All options to be rendered, without any visibility filtering applied.
+ '';
+ };
+ config.docs =
+ lib.zipAttrsWith
+ (name: values:
+ if length values > 1 then
+ traceListSeq values
+ abort "Multiple options with the same name: ${name}"
+ else
+ assert length values == 1;
+ head values
+ )
+ (map
+ (opt: { ${opt.name} = opt; })
+ (lib.optionAttrSetToDocList options)
+ );
+}

lib/tests/modules/types-attrTag-wrong-decl.nix

@@ -0,0 +1,14 @@
+{ lib, ... }:
+let
+ inherit (lib) types mkOption;
+in
+{
+ options = {
+ opt = mkOption {
+ type = types.attrTag {
+ int = types.int;
+ };
+ default = { int = 1; };
+ };
+ };
+}

lib/tests/modules/types-attrTag.nix

@@ -0,0 +1,135 @@
+{ lib, config, options, ... }:
+let
+ inherit (lib) mkOption types;
+ forceDeep = x: builtins.deepSeq x x;
+ mergedSubOption = (options.merged.type.getSubOptions options.merged.loc).extensible."merged.<name>";
+in
+{
+ options = {
+ intStrings = mkOption {
+ type = types.attrsOf
+ (types.attrTag {
+ left = mkOption {
+ type = types.int;
+ };
+ right = mkOption {
+ type = types.str;
+ };
+ });
+ };
+ nested = mkOption {
+ type = types.attrTag {
+ left = mkOption {
+ type = types.int;
+ };
+ right = mkOption {
+ type = types.attrTag {
+ left = mkOption {
+ type = types.int;
+ };
+ right = mkOption {
+ type = types.str;
+ };
+ };
+ };
+ };
+ };
+ merged = mkOption {
+ type = types.attrsOf (
+ types.attrTag {
+ yay = mkOption {
+ type = types.int;
+ };
+ extensible = mkOption {
+ type = types.enum [ "foo" ];
+ };
+ }
+ );
+ };
+ submodules = mkOption {
+ type = types.attrsOf (
+ types.attrTag {
+ foo = mkOption {
+ type = types.submodule {
+ options = {
+ bar = mkOption {
+ type = types.int;
+ };
+ };
+ };
+ };
+ qux = mkOption {
+ type = types.str;
+ description = "A qux for when you don't want a foo";
+ };
+ }
+ );
+ };
+ okChecks = mkOption {};
+ };
+ imports = [
+ ./docs.nix
+ {
+ options.merged = mkOption {
+ type = types.attrsOf (
+ types.attrTag {
+ nay = mkOption {
+ type = types.bool;
+ };
+ extensible = mkOption {
+ type = types.enum [ "bar" ];
+ };
+ }
+ );
+ };
+ }
+ ];
+ config = {
+ intStrings.syntaxError = 1;
+ intStrings.syntaxError2 = {};
+ intStrings.syntaxError3 = { a = true; b = true; };
+ intStrings.syntaxError4 = lib.mkMerge [ { a = true; } { b = true; } ];
+ intStrings.mergeError = lib.mkMerge [ { int = throw "do not eval"; } { string = throw "do not eval"; } ];
+ intStrings.badTagError.rite = throw "do not eval";
+ intStrings.badTagTypeError.left = "bad";
+ intStrings.numberOne.left = 1;
+ intStrings.hello.right = "hello world";
+ nested.right.left = "not a number";
+ merged.negative.nay = false;
+ merged.positive.yay = 100;
+ merged.extensi-foo.extensible = "foo";
+ merged.extensi-bar.extensible = "bar";
+ okChecks = builtins.addErrorContext "while evaluating the assertions" (
+ assert config.intStrings.hello == { right = "hello world"; };
+ assert config.intStrings.numberOne == { left = 1; };
+ assert config.merged.negative == { nay = false; };
+ assert config.merged.positive == { yay = 100; };
+ assert config.merged.extensi-foo == { extensible = "foo"; };
+ assert config.merged.extensi-bar == { extensible = "bar"; };
+ assert config.docs."submodules.<name>.foo.bar".type == "signed integer";
+ assert config.docs."submodules.<name>.qux".type == "string";
+ assert config.docs."submodules.<name>.qux".declarations == [ __curPos.file ];
+ assert config.docs."submodules.<name>.qux".loc == [ "submodules" "<name>" "qux" ];
+ assert config.docs."submodules.<name>.qux".name == "submodules.<name>.qux";
+ assert config.docs."submodules.<name>.qux".description == "A qux for when you don't want a foo";
+ assert config.docs."submodules.<name>.qux".readOnly == false;
+ assert config.docs."submodules.<name>.qux".visible == true;
+ # Not available (yet?)
+ # assert config.docs."submodules.<name>.qux".declarationsWithPositions == [ ... ];
+ assert options.submodules.declarations == [ __curPos.file ];
+ assert lib.length options.submodules.declarationPositions == 1;
+ assert (lib.head options.submodules.declarationPositions).file == __curPos.file;
+ assert options.merged.declarations == [ __curPos.file __curPos.file ];
+ assert lib.length options.merged.declarationPositions == 2;
+ assert (lib.elemAt options.merged.declarationPositions 0).file == __curPos.file;
+ assert (lib.elemAt options.merged.declarationPositions 1).file == __curPos.file;
+ assert (lib.elemAt options.merged.declarationPositions 0).line != (lib.elemAt options.merged.declarationPositions 1).line;
+ assert mergedSubOption.declarations == [ __curPos.file __curPos.file ];
+ assert lib.length mergedSubOption.declarationPositions == 2;
+ assert (lib.elemAt mergedSubOption.declarationPositions 0).file == __curPos.file;
+ assert (lib.elemAt mergedSubOption.declarationPositions 1).file == __curPos.file;
+ assert (lib.elemAt mergedSubOption.declarationPositions 0).line != (lib.elemAt mergedSubOption.declarationPositions 1).line;
+ assert lib.length config.docs."merged.<name>.extensible".declarations == 2;
+ true);
+ };
+}

lib/types.nix

@@ -15,6 +15,7 @@ let
  isList
  isString
  isStorePath
+ throwIf
  toDerivation
  toList
  ;
@@ -65,6 +66,11 @@ let
  fixupOptionType
  mergeOptionDecls
  ;
+
+ inAttrPosSuffix = v: name:
+ let pos = builtins.unsafeGetAttrPos name v; in
+ if pos == null then "" else " at ${pos.file}:${toString pos.line}:${toString pos.column}";
+
  outer_types =
 rec {
  __attrsFailEvaluation = true;
@@ -152,7 +158,7 @@ rec {
  # If it doesn't, this should be {}
  # This may be used when a value is required for `mkIf false`. This allows the extra laziness in e.g. `lazyAttrsOf`.
  emptyValue ? {}
- , # Return a flat list of sub-options. Used to generate
+ , # Return a flat attrset of sub-options. Used to generate
  # documentation.
  getSubOptions ? prefix: {}
  , # List of modules if any, or null if none.
@@ -623,6 +629,100 @@ rec {
  nestedTypes.elemType = elemType;
  };
 
+ attrTag = tags:
+ let tags_ = tags; in
+ let
+ tags =
+ mapAttrs
+ (n: opt:
+ builtins.addErrorContext "while checking that attrTag tag ${lib.strings.escapeNixIdentifier n} is an option with a type${inAttrPosSuffix tags_ n}" (
+ throwIf (opt._type or null != "option")
+ "In attrTag, each tag value must be an option, but tag ${lib.strings.escapeNixIdentifier n} ${
+ if opt?_type then
+ if opt._type == "option-type"
+ then "was a bare type, not wrapped in mkOption."
+ else "was of type ${lib.strings.escapeNixString opt._type}."
+ else "was not."}"
+ opt // {
+ declarations = opt.declarations or (
+ let pos = builtins.unsafeGetAttrPos n tags_;
+ in if pos == null then [] else [ pos.file ]
+ );
+ declarationPositions = opt.declarationPositions or (
+ let pos = builtins.unsafeGetAttrPos n tags_;
+ in if pos == null then [] else [ pos ]
+ );
+ }
+ ))
+ tags_;
+ choicesStr = concatMapStringsSep ", " lib.strings.escapeNixIdentifier (attrNames tags);
+ in
+ mkOptionType {
+ name = "attrTag";
+ description = "attribute-tagged union";
+ descriptionClass = "noun";
+ getSubOptions = prefix:
+ mapAttrs
+ (tagName: tagOption: {
+ "${lib.showOption prefix}" =
+ tagOption // {
+ loc = prefix ++ [ tagName ];
+ };
+ })
+ tags;
+ check = v: isAttrs v && length (attrNames v) == 1 && tags?${head (attrNames v)};
+ merge = loc: defs:
+ let
+ choice = head (attrNames (head defs).value);
+ checkedValueDefs = map
+ (def:
+ assert (length (attrNames def.value)) == 1;
+ if (head (attrNames def.value)) != choice
+ then throw "The option `${showOption loc}` is defined both as `${choice}` and `${head (attrNames def.value)}`, in ${showFiles (getFiles defs)}."
+ else { inherit (def) file; value = def.value.${choice}; })
+ defs;
+ in
+ if tags?${choice}
+ then
+ { ${choice} =
+ (lib.modules.evalOptionValue
+ (loc ++ [choice])
+ tags.${choice}
+ checkedValueDefs
+ ).value;
+ }
+ else throw "The option `${showOption loc}` is defined as ${lib.strings.escapeNixIdentifier choice}, but ${lib.strings.escapeNixIdentifier choice} is not among the valid choices (${choicesStr}). Value ${choice} was defined in ${showFiles (getFiles defs)}.";
+ nestedTypes = tags;
+ functor = defaultFunctor "attrTag" // {
+ type = { tags, ... }: types.attrTag tags;
+ payload = { inherit tags; };
+ binOp =
+ let
+ # Add metadata in the format that submodules work with
+ wrapOptionDecl =
+ option: { options = option; _file = "<attrTag {...}>"; pos = null; };
+ in
+ a: b: {
+ tags = a.tags // b.tags //
+ mapAttrs
+ (tagName: bOpt:
+ lib.mergeOptionDecls
+ # FIXME: loc is not accurate; should include prefix
+ # Fortunately, it's only used for error messages, where a "relative" location is kinda ok.
+ # It is also returned though, but use of the attribute seems rare?
+ [tagName]
+ [ (wrapOptionDecl a.tags.${tagName}) (wrapOptionDecl bOpt) ]
+ // {
+ # mergeOptionDecls is not idempotent in these attrs:
+ declarations = a.tags.${tagName}.declarations ++ bOpt.declarations;
+ declarationPositions = a.tags.${tagName}.declarationPositions ++ bOpt.declarationPositions;
+ }
+ )
+ (builtins.intersectAttrs a.tags b.tags);
+ };
+ };
+ };
+
  uniq = unique { message = ""; };
 
  unique = { message }: type: mkOptionType rec {