From a5576c60f7ad489015c8fc7d9216dceca8ec4af4 Mon Sep 17 00:00:00 2001 From: Simon Bruder Date: Sat, 27 Feb 2021 12:13:28 +0100 Subject: [PATCH] Refactor nix pre-commit hoooks --- default.nix | 11 ---- nix/sources.json | 26 +++++++++ nix/sources.nix | 149 +++++++++++++++++++++++++++++++++++++++++++++++ pre-commit.nix | 11 ++++ shell.nix | 9 ++- 5 files changed, 192 insertions(+), 14 deletions(-) delete mode 100644 default.nix create mode 100644 nix/sources.json create mode 100644 nix/sources.nix create mode 100644 pre-commit.nix diff --git a/default.nix b/default.nix deleted file mode 100644 index dbe1513..0000000 --- a/default.nix +++ /dev/null @@ -1,11 +0,0 @@ -let - nix-pre-commit-hooks = import (builtins.fetchTarball "https://github.com/cachix/pre-commit-hooks.nix/tarball/master"); -in -{ - pre-commit-check = nix-pre-commit-hooks.run { - src = ./.; - hooks = { - black.enable = true; - }; - }; -} diff --git a/nix/sources.json b/nix/sources.json new file mode 100644 index 0000000..727d9e9 --- /dev/null +++ b/nix/sources.json @@ -0,0 +1,26 @@ +{ + "nixpkgs": { + "branch": "nixos-20.09", + "description": "Nix Packages collection", + "homepage": "", + "owner": "NixOS", + "repo": "nixpkgs", + "rev": "42809feaa9f7474f5566a5c6e8e317e15e39160e", + "sha256": "12cnyxx316pwhw069brqsx8v23b10akqlf0vhkilaimsksv7cwgm", + "type": "tarball", + "url": "https://github.com/NixOS/nixpkgs/archive/42809feaa9f7474f5566a5c6e8e317e15e39160e.tar.gz", + "url_template": "https://github.com///archive/.tar.gz" + }, + "pre-commit-hooks.nix": { + "branch": "master", + "description": "Seamless integration of https://pre-commit.com git hooks with Nix.", + "homepage": "", + "owner": "cachix", + "repo": "pre-commit-hooks.nix", + "rev": "431227b41d0aaa83fabdee6611e145b7d9bd150b", + "sha256": "0ff24n8i3mfw0jw5r5lsgvbahmh88zhi3qsk9yxrb8x82jprgzsy", + "type": "tarball", + "url": "https://github.com/cachix/pre-commit-hooks.nix/archive/431227b41d0aaa83fabdee6611e145b7d9bd150b.tar.gz", + "url_template": "https://github.com///archive/.tar.gz" + } +} diff --git a/nix/sources.nix b/nix/sources.nix new file mode 100644 index 0000000..f614e68 --- /dev/null +++ b/nix/sources.nix @@ -0,0 +1,149 @@ +# This file has been generated by Niv. +let + # + # The fetchers. fetch_ fetches specs of type . + # + + fetch_file = pkgs: spec: + if spec.builtin or true then + builtins_fetchurl { inherit (spec) url sha256; } + else + pkgs.fetchurl { inherit (spec) url sha256; }; + + fetch_tarball = pkgs: name: spec: + let + ok = str: ! builtins.isNull (builtins.match "[a-zA-Z0-9+-._?=]" str); + # sanitize the name, though nix will still fail if name starts with period + name' = stringAsChars (x: if ! ok x then "-" else x) "${name}-src"; + in + if spec.builtin or true then + builtins_fetchTarball { name = name'; inherit (spec) url sha256; } + else + pkgs.fetchzip { name = name'; inherit (spec) url sha256; }; + + fetch_git = spec: + builtins.fetchGit { url = spec.repo; inherit (spec) rev ref; }; + + fetch_local = spec: spec.path; + + fetch_builtin-tarball = name: throw + ''[${name}] The niv type "builtin-tarball" is deprecated. You should instead use `builtin = true`. + $ niv modify ${name} -a type=tarball -a builtin=true''; + + fetch_builtin-url = name: throw + ''[${name}] The niv type "builtin-url" will soon be deprecated. You should instead use `builtin = true`. + $ niv modify ${name} -a type=file -a builtin=true''; + + # + # Various helpers + # + + # The set of packages used when specs are fetched using non-builtins. + mkPkgs = sources: + let + sourcesNixpkgs = + import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) { }; + hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath; + hasThisAsNixpkgsPath = == ./.; + in + if builtins.hasAttr "nixpkgs" sources + then sourcesNixpkgs + else if hasNixpkgsPath && ! hasThisAsNixpkgsPath then + import { } + else + abort + '' + Please specify either (through -I or NIX_PATH=nixpkgs=...) or + add a package called "nixpkgs" to your sources.json. + ''; + + # The actual fetching function. + fetch = pkgs: name: spec: + + if ! builtins.hasAttr "type" spec then + abort "ERROR: niv spec ${name} does not have a 'type' attribute" + else if spec.type == "file" then fetch_file pkgs spec + else if spec.type == "tarball" then fetch_tarball pkgs name spec + else if spec.type == "git" then fetch_git spec + else if spec.type == "local" then fetch_local spec + else if spec.type == "builtin-tarball" then fetch_builtin-tarball name + else if spec.type == "builtin-url" then fetch_builtin-url name + else + abort "ERROR: niv spec ${name} has unknown type ${builtins.toJSON spec.type}"; + + # If the environment variable NIV_OVERRIDE_${name} is set, then use + # the path directly as opposed to the fetched source. + replace = name: drv: + let + saneName = stringAsChars (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name; + ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}"; + in + if ersatz == "" then drv else ersatz; + + # Ports of functions for older nix versions + + # a Nix version of mapAttrs if the built-in doesn't exist + mapAttrs = builtins.mapAttrs or ( + f: set: with builtins; + listToAttrs (map (attr: { name = attr; value = f attr set.${attr}; }) (attrNames set)) + ); + + # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295 + range = first: last: if first > last then [ ] else builtins.genList (n: first + n) (last - first + 1); + + # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257 + stringToCharacters = s: map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1)); + + # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269 + stringAsChars = f: s: concatStrings (map f (stringToCharacters s)); + concatStrings = builtins.concatStringsSep ""; + + # fetchTarball version that is compatible between all the versions of Nix + builtins_fetchTarball = { url, name, sha256 }@attrs: + let + inherit (builtins) lessThan nixVersion fetchTarball; + in + if lessThan nixVersion "1.12" then + fetchTarball { inherit name url; } + else + fetchTarball attrs; + + # fetchurl version that is compatible between all the versions of Nix + builtins_fetchurl = { url, sha256 }@attrs: + let + inherit (builtins) lessThan nixVersion fetchurl; + in + if lessThan nixVersion "1.12" then + fetchurl { inherit url; } + else + fetchurl attrs; + + # Create the final "sources" from the config + mkSources = config: + mapAttrs + ( + name: spec: + if builtins.hasAttr "outPath" spec + then + abort + "The values in sources.json should not have an 'outPath' attribute" + else + spec // { outPath = replace name (fetch config.pkgs name spec); } + ) + config.sources; + + # The "config" used by the fetchers + mkConfig = + { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null + , sources ? if isNull sourcesFile then { } else builtins.fromJSON (builtins.readFile sourcesFile) + , pkgs ? mkPkgs sources + }: rec { + # The sources, i.e. the attribute set of spec name to spec + inherit sources; + + # The "pkgs" (evaluated nixpkgs) to use for e.g. non-builtin fetchers + inherit pkgs; + }; + +in +mkSources (mkConfig { }) // { __functor = _: settings: mkSources (mkConfig settings); } diff --git a/pre-commit.nix b/pre-commit.nix new file mode 100644 index 0000000..c730bf6 --- /dev/null +++ b/pre-commit.nix @@ -0,0 +1,11 @@ +let + nix-pre-commit-hooks = import (import ./nix/sources.nix)."pre-commit-hooks.nix"; +in +nix-pre-commit-hooks.run { + src = ./.; + hooks = { + black.enable = true; + nixpkgs-fmt.enable = true; + shellcheck.enable = true; + }; +} diff --git a/shell.nix b/shell.nix index 5d14712..9ed1eda 100644 --- a/shell.nix +++ b/shell.nix @@ -1,10 +1,13 @@ -{ pkgs ? import {} }: - +let + sources = import ./nix/sources.nix; + pkgs = import sources.nixpkgs { }; +in pkgs.mkShell { nativeBuildInputs = with pkgs; [ + git nixpkgs-fmt ]; shellHook = '' - ${(import ./default.nix).pre-commit-check.shellHook} + ${(import ./pre-commit.nix).shellHook} ''; }