From efdf618330a22f837f0e5e446028e918a5b4dd8a Mon Sep 17 00:00:00 2001 From: Profpatsch Date: Wed, 8 Aug 2018 19:26:52 +0200 Subject: [PATCH] lib: move assertMsg and assertOneOf to their own library file Since the `assertOneOf` uses `lib.generators`, they are not really trivial anymore and should go into their own library file. --- lib/asserts.nix | 44 ++++++++++++++++++++++++++++++++++++++++++++ lib/default.nix | 9 +++++---- lib/lists.nix | 4 ++-- lib/trivial.nix | 40 +--------------------------------------- lib/types.nix | 2 +- 5 files changed, 53 insertions(+), 46 deletions(-) create mode 100644 lib/asserts.nix diff --git a/lib/asserts.nix b/lib/asserts.nix new file mode 100644 index 00000000000..8a5f1fb3feb --- /dev/null +++ b/lib/asserts.nix @@ -0,0 +1,44 @@ +{ lib }: + +rec { + + /* Print a trace message if pred is false. + Intended to be used to augment asserts with helpful error messages. + + Example: + assertMsg false "nope" + => false + stderr> trace: nope + + assert (assertMsg ("foo" == "bar") "foo is not bar, silly"); "" + stderr> trace: foo is not bar, silly + stderr> assert failed at … + + Type: + assertMsg :: Bool -> String -> Bool + */ + # TODO(Profpatsch): add tests that check stderr + assertMsg = pred: msg: + if pred + then true + else builtins.trace msg false; + + /* Specialized `assertMsg` for checking if val is one of the elements + of a list. Useful for checking enums. + + Example: + let sslLibrary = "libressl" + in assertOneOf "sslLibrary" sslLibrary [ "openssl" "bearssl" ] + => false + stderr> trace: sslLibrary must be one of "openssl", "bearssl", but is: "libressl" + + Type: + assertOneOf :: String -> ComparableVal -> List ComparableVal -> Bool + */ + assertOneOf = name: val: xs: assertMsg + (lib.elem val xs) + "${name} must be one of ${ + lib.generators.toPretty {} xs}, but is: ${ + lib.generators.toPretty {} val}"; + +} diff --git a/lib/default.nix b/lib/default.nix index 358c8ca0b8f..d7a05fec833 100644 --- a/lib/default.nix +++ b/lib/default.nix @@ -38,10 +38,11 @@ let systems = callLibs ./systems; # misc + asserts = callLibs ./asserts.nix; debug = callLibs ./debug.nix; - generators = callLibs ./generators.nix; misc = callLibs ./deprecated.nix; + # domain-specific fetchers = callLibs ./fetchers.nix; @@ -59,9 +60,7 @@ let inherit (trivial) id const concat or and bitAnd bitOr bitXor bitNot boolToString mergeAttrs flip mapNullable inNixShell min max importJSON warn info nixpkgsVersion version mod compare - splitByAndCompare functionArgs setFunctionArgs isFunction - assertMsg assertOneOf; - + splitByAndCompare functionArgs setFunctionArgs isFunction; inherit (fixedPoints) fix fix' extends composeExtensions makeExtensible makeExtensibleWithCustomName; inherit (attrsets) attrByPath hasAttrByPath setAttrByPath @@ -118,6 +117,8 @@ let unknownModule mkOption; inherit (types) isType setType defaultTypeMerge defaultFunctor isOptionType mkOptionType; + inherit (asserts) + assertMsg assertOneOf; inherit (debug) addErrorContextToAttrs traceIf traceVal traceValFn traceXMLVal traceXMLValMarked traceSeq traceSeqN traceValSeq traceValSeqFn traceValSeqN traceValSeqNFn traceShowVal diff --git a/lib/lists.nix b/lib/lists.nix index 9a75f179e96..9ecd8f22003 100644 --- a/lib/lists.nix +++ b/lib/lists.nix @@ -509,7 +509,7 @@ rec { => 3 */ last = list: - assert assertMsg (list != []) "lists.last: list must not be empty!"; + assert lib.assertMsg (list != []) "lists.last: list must not be empty!"; elemAt list (length list - 1); /* Return all elements but the last @@ -519,7 +519,7 @@ rec { => [ 1 2 ] */ init = list: - assert assertMsg (list != []) "lists.init: list must not be empty!"; + assert lib.assertMsg (list != []) "lists.init: list must not be empty!"; take (length list - 1) list; diff --git a/lib/trivial.nix b/lib/trivial.nix index f1001ee10ca..b1eea0bf124 100644 --- a/lib/trivial.nix +++ b/lib/trivial.nix @@ -171,7 +171,7 @@ rec { builtins.fromJSON (builtins.readFile path); - ## Warnings and asserts + ## Warnings /* See https://github.com/NixOS/nix/issues/749. Eventually we'd like these to expand to Nix builtins that carry metadata so that Nix can filter out @@ -188,44 +188,6 @@ rec { warn = msg: builtins.trace "WARNING: ${msg}"; info = msg: builtins.trace "INFO: ${msg}"; - /* Print a trace message if pred is false. - Intended to be used to augment asserts with helpful error messages. - - Example: - assertMsg false "nope" - => false - stderr> trace: nope - - assert (assertMsg ("foo" == "bar") "foo is not bar, silly"); "" - stderr> trace: foo is not bar, silly - stderr> assert failed at … - - Type: - assertMsg :: Bool -> String -> Bool - */ - # TODO(Profpatsch): add tests that check stderr - assertMsg = pred: msg: - if pred - then true - else builtins.trace msg false; - - /* Specialized `assertMsg` for checking if val is one of the elements - of a list. Useful for checking enums. - - Example: - let sslLibrary = "libressl" - in assertOneOf "sslLibrary" sslLibrary [ "openssl" "bearssl" ] - => false - stderr> trace: sslLibrary must be one of "openssl", "bearssl", but is: "libressl" - - Type: - assertOneOf :: String -> ComparableVal -> List ComparableVal -> Bool - */ - assertOneOf = name: val: xs: assertMsg - (lib.elem val xs) - "${name} must be one of ${ - lib.generators.toPretty {} xs}, but is: ${ - lib.generators.toPretty {} val}"; ## Function annotations diff --git a/lib/types.nix b/lib/types.nix index 441af98cb9b..4e44e7521c4 100644 --- a/lib/types.nix +++ b/lib/types.nix @@ -441,7 +441,7 @@ rec { # Either value of type `finalType` or `coercedType`, the latter is # converted to `finalType` using `coerceFunc`. coercedTo = coercedType: coerceFunc: finalType: - assert assertMsg (coercedType.getSubModules == null) + assert lib.assertMsg (coercedType.getSubModules == null) "coercedTo: coercedType must not have submodules (it’s a ${ coercedType.description})"; mkOptionType rec {