Merge pull request avh4#559 from avh4/release-prep

Automate updating the nix package

PUBLISHING.md

@@ -67,3 +67,13 @@ npm dist-tag add elm-format@<new version> elm0.18.0
 npm dist-tag add elm-format@<new version> elm0.19.0
 npm dist-tag add elm-format@<new version> exp
 ```
+
+
+## Nix
+
+```
+cd package/nix
+./build.sh
+```
+
+Then `cd nixpkgs`, push the resulting branch, and make a PR to https://github.com/NixOS/nixpkgs with the title "elm-format: [old version] -> [new version]"

package/nix/.gitignore

@@ -0,0 +1 @@
+/nixpkgs

package/nix/build.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+
+set -exo pipefail
+
+ELM_FORMAT_VERSION="$(git describe --abbrev=8)"
+BRANCH="elm-format-$ELM_FORMAT_VERSION"
+
+if [ ! -d nixpkgs ]; then
+  git clone https://github.com/NixOS/nixpkgs.git nixpkgs
+fi
+
+pushd nixpkgs
+git fetch origin master
+if git branch | grep " ${BRANCH}$"; then
+  git checkout "$BRANCH"
+  git reset --hard origin/master
+else
+  git checkout -b "$BRANCH" origin/master
+fi
+popd
+
+cabal2nix --no-check cabal://indents-0.3.3 > nixpkgs/pkgs/development/compilers/elm/packages/indents.nix
+cabal2nix --no-check cabal://tasty-quickcheck-0.9.2 > nixpkgs/pkgs/development/compilers/elm/packages/tasty-quickcheck.nix
+./generate_derivation.sh > nixpkgs/pkgs/development/compilers/elm/packages/elm-format.nix
+
+pushd nixpkgs
+rm -f result
+nix-build -A elmPackages.elm-format
+git status
+result/bin/elm-format | head -n1
+popd
+
+set +x
+
+echo
+echo "Everything looks good!"
+echo "You will need to make a PR from the $BRANCH branch"

package/nix/generate_derivation.sh

@@ -0,0 +1,43 @@
+#! /usr/bin/env nix-shell
+#! nix-shell -i bash -p git cabal2nix nix-prefetch-git jq
+
+# This script generates the nix derivation for elm-format intended for nixpkgs:
+# https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/compilers/elm/packages/elm-format.nix
+
+# To use this script, run:
+#
+# $ ./generate_derivation.sh > elm-format.nix
+#
+# This might take a bit of time if the dependencies are not already in the nix
+# store. If you already have all the dependencies installed, feel free to remove
+# them from the shebang to speed up the process.
+
+set -exo pipefail
+
+REV="$(git rev-parse HEAD)"
+VERSION="$(git describe --abbrev=8 "$REV")"
+ROOTDIR="$(git rev-parse --show-toplevel)"
+SHA="$(nix-prefetch-git --url "$ROOTDIR" --rev "$REV" --quiet --no-deepClone | jq --raw-output .sha256)"
+
+PATCH=$(cat <<END
+  src = fetchgit {
+    url = "http://github.com/avh4/elm-format";
+    sha256 = "$SHA";
+    rev = "$REV";
+  };
+  postPatch = ''
+    sed -i "s|desc <-.*||" ./Setup.hs
+    sed -i "s|gitDescribe = .*|gitDescribe = \\\\\\\\\"$VERSION\\\\\\\\\"\"|" ./Setup.hs
+  '';
+END
+)
+
+# quoteSubst from https://stackoverflow.com/a/29613573
+quoteSubst() {
+  IFS= read -d '' -r < <(sed -e ':a' -e '$!{N;ba' -e '}' -e 's/[&/\]/\\&/g; s/\n/\\&/g' <<<"$1")
+  printf %s "${REPLY%$'\n'}"
+}
+
+cabal2nix --no-haddock "$ROOTDIR" |
+  sed "s#^{ mkDerivation#{ mkDerivation, fetchgit#" |
+  sed "s#\\s*src = .*;#$(quoteSubst "$PATCH")#"