Refactor nix pre-commit hoooks

This commit is contained in:
Simon Bruder 2021-02-27 12:13:28 +01:00
parent 46a4a8245e
commit a5576c60f7
Signed by: simon
GPG key ID: 8D3C82F9F309F8EC
5 changed files with 192 additions and 14 deletions

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@ -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;
};
};
}

26
nix/sources.json Normal file
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{
"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/<owner>/<repo>/archive/<rev>.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/<owner>/<repo>/archive/<rev>.tar.gz"
}
}

149
nix/sources.nix Normal file
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# This file has been generated by Niv.
let
#
# The fetchers. fetch_<type> fetches specs of type <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 = <nixpkgs> == ./.;
in
if builtins.hasAttr "nixpkgs" sources
then sourcesNixpkgs
else if hasNixpkgsPath && ! hasThisAsNixpkgsPath then
import <nixpkgs> { }
else
abort
''
Please specify either <nixpkgs> (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); }

11
pre-commit.nix Normal file
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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;
};
}

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@ -1,10 +1,13 @@
{ pkgs ? import <nixpkgs> {} }: let
sources = import ./nix/sources.nix;
pkgs = import sources.nixpkgs { };
in
pkgs.mkShell { pkgs.mkShell {
nativeBuildInputs = with pkgs; [ nativeBuildInputs = with pkgs; [
git
nixpkgs-fmt nixpkgs-fmt
]; ];
shellHook = '' shellHook = ''
${(import ./default.nix).pre-commit-check.shellHook} ${(import ./pre-commit.nix).shellHook}
''; '';
} }