remove mkYarnPackage

The Nix file for mkYarnPackage must be in the nixpkgs repository,
because Hydra does not allow importing Nix files from downloaded paths.
To prevent the nixpkgs version of the Nix code from getting out-of-sync
with this repository, let's remove it here and use nixpkgs as the single
source of truth for the Nix code.
Incompatibilities in the interface can be dealt with by adding an
attribute for the yarn.nix file format version in the future.

default.nix

@@ -1,377 +1,18 @@
 { pkgs ? import <nixpkgs> {}
 , nodejs ? pkgs.nodejs
 , yarn ? pkgs.yarn
+, src ? ./.
 }:
 
 let
-  inherit (pkgs) stdenv lib fetchurl linkFarm callPackage git rsync makeWrapper;
+  inherit (pkgs) stdenv lib callPackage git rsync makeWrapper yarn2nix-moretea;
+  inherit (yarn2nix-moretea) mkYarnPackage defaultYarnFlags;
 
-  compose = f: g: x: f (g x);
-  id = x: x;
-  composeAll = builtins.foldl' compose id;
 in rec {
-  # Export yarn again to make it easier to find out which yarn was used.
-  inherit yarn;
-
-  # Re-export pkgs
-  inherit pkgs;
-
-  unlessNull = item: alt:
-    if item == null then alt else item;
-
-  reformatPackageName = pname:
-    let
-      # regex adapted from `validate-npm-package-name`
-      # will produce 3 parts e.g.
-      # "@someorg/somepackage" -> [ "@someorg/" "someorg" "somepackage" ]
-      # "somepackage" -> [ null null "somepackage" ]
-      parts = builtins.tail (builtins.match "^(@([^/]+)/)?([^/]+)$" pname);
-      # if there is no organisation we need to filter out null values.
-      non-null = builtins.filter (x: x != null) parts;
-    in builtins.concatStringsSep "-" non-null;
-
-  # https://docs.npmjs.com/files/package.json#license
-  # TODO: support expression syntax (OR, AND, etc)
-  spdxLicense = licstr:
-    if licstr == "UNLICENSED" then
-      lib.licenses.unfree
-    else
-      lib.findFirst
-        (l: l ? spdxId && l.spdxId == licstr)
-        { shortName = licstr; }
-        (builtins.attrValues lib.licenses);
-
-  # Generates the yarn.nix from the yarn.lock file
-  mkYarnNix = { yarnLock, flags ? [] }:
-    pkgs.runCommand "yarn.nix" {}
-    "${yarn2nix}/bin/yarn2nix --lockfile ${yarnLock} --no-patch --builtin-fetchgit ${lib.escapeShellArgs flags} > $out";
-
-  # Loads the generated offline cache. This will be used by yarn as
-  # the package source.
-  importOfflineCache = yarnNix:
-    let
-      pkg = callPackage yarnNix { };
-    in
-      pkg.offline_cache;
-
-  defaultYarnFlags = [
-    "--offline"
-    "--frozen-lockfile"
-    "--ignore-engines"
-    "--ignore-scripts"
-  ];
-
-  mkYarnModules = {
-    name, # safe name and version, e.g. testcompany-one-modules-1.0.0
-    pname, # original name, e.g @testcompany/one
-    version,
-    packageJSON,
-    yarnLock,
-    yarnNix ? mkYarnNix { inherit yarnLock; },
-    yarnFlags ? defaultYarnFlags,
-    pkgConfig ? {},
-    preBuild ? "",
-    postBuild ? "",
-    workspaceDependencies ? [], # List of yarn packages
-  }:
-    let
-      offlineCache = importOfflineCache yarnNix;
-
-      extraBuildInputs = (lib.flatten (builtins.map (key:
-        pkgConfig.${key}.buildInputs or []
-      ) (builtins.attrNames pkgConfig)));
-
-      postInstall = (builtins.map (key:
-        if (pkgConfig.${key} ? postInstall) then
-          ''
-            for f in $(find -L -path '*/node_modules/${key}' -type d); do
-              (cd "$f" && (${pkgConfig.${key}.postInstall}))
-            done
-          ''
-        else
-          ""
-      ) (builtins.attrNames pkgConfig));
-
-      workspaceJSON = pkgs.writeText
-        "${name}-workspace-package.json"
-        (builtins.toJSON { private = true; workspaces = ["deps/**"]; }); # scoped packages need second splat
-
-      workspaceDependencyLinks = lib.concatMapStringsSep "\n"
-        (dep: ''
-          mkdir -p "deps/${dep.pname}"
-          ln -sf ${dep.packageJSON} "deps/${dep.pname}/package.json"
-        '')
-        workspaceDependencies;
-
-    in stdenv.mkDerivation {
-      inherit preBuild postBuild name;
-      phases = ["configurePhase" "buildPhase"];
-      buildInputs = [ yarn nodejs git ] ++ extraBuildInputs;
-
-      configurePhase = ''
-        # Yarn writes cache directories etc to $HOME.
-        export HOME=$PWD/yarn_home
-      '';
-
-      buildPhase = ''
-        runHook preBuild
-
-        mkdir -p "deps/${pname}"
-        cp ${packageJSON} "deps/${pname}/package.json"
-        cp ${workspaceJSON} ./package.json
-        cp ${yarnLock} ./yarn.lock
-        chmod +w ./yarn.lock
-
-        yarn config --offline set yarn-offline-mirror ${offlineCache}
-
-        # Do not look up in the registry, but in the offline cache.
-        ${fixup_yarn_lock}/bin/fixup_yarn_lock yarn.lock
-
-        ${workspaceDependencyLinks}
-
-        # Set the nodedir so we can build native packages.
-        yarn config --offline set nodedir ${nodejs}
-        yarn install ${lib.escapeShellArgs yarnFlags}
-
-        ${lib.concatStringsSep "\n" postInstall}
-
-        mkdir $out
-        mv node_modules $out/
-        mv deps $out/
-        patchShebangs $out
-
-        runHook postBuild
-      '';
-    };
-
-  # This can be used as a shellHook in mkYarnPackage. It brings the built node_modules into
-  # the shell-hook environment.
-  linkNodeModulesHook = ''
-    if [[ -d node_modules || -L node_modules ]]; then
-      echo "./node_modules is present. Replacing."
-      rm -rf node_modules
-    fi
-
-    ln -s "$node_modules" node_modules
-  '';
-
-  mkYarnWorkspace = {
-    src,
-    packageJSON ? src + "/package.json",
-    yarnLock ? src + "/yarn.lock",
-    packageOverrides ? {},
-    ...
-  }@attrs:
-  let
-    package = lib.importJSON packageJSON;
-
-    packageGlobs = package.workspaces;
-
-    globElemToRegex = lib.replaceStrings ["*"] [".*"];
-
-    # PathGlob -> [PathGlobElem]
-    splitGlob = lib.splitString "/";
-
-    # Path -> [PathGlobElem] -> [Path]
-    # Note: Only directories are included, everything else is filtered out
-    expandGlobList = base: globElems:
-      let
-        elemRegex = globElemToRegex (lib.head globElems);
-        rest = lib.tail globElems;
-        children = lib.attrNames (lib.filterAttrs (name: type: type == "directory") (builtins.readDir base));
-        matchingChildren = lib.filter (child: builtins.match elemRegex child != null) children;
-      in if globElems == []
-        then [ base ]
-        else lib.concatMap (child: expandGlobList (base+("/"+child)) rest) matchingChildren;
-
-    # Path -> PathGlob -> [Path]
-    expandGlob = base: glob: expandGlobList base (splitGlob glob);
-
-    packagePaths = lib.concatMap (expandGlob src) packageGlobs;
-
-    packages = lib.listToAttrs (map (src:
-      let
-        packageJSON = src + "/package.json";
-
-        package = lib.importJSON packageJSON;
-
-        allDependencies = lib.foldl (a: b: a // b) {} (map (field: lib.attrByPath [field] {} package) ["dependencies" "devDependencies"]);
-
-        # { [name: String] : { pname : String, packageJSON : String, ... } } -> { [pname: String] : version } -> [{ pname : String, packageJSON : String, ... }]
-        getWorkspaceDependencies = packages: allDependencies:
-          let
-            packageList = lib.attrValues packages;
-          in
-            composeAll [
-              (lib.filter (x: x != null))
-              (lib.mapAttrsToList (pname: _version: lib.findFirst (package: package.pname == pname) null packageList))
-            ] allDependencies;
-
-        workspaceDependencies = getWorkspaceDependencies packages allDependencies;
-
-        name = reformatPackageName package.name;
-      in {
-        inherit name;
-        value = mkYarnPackage (
-          builtins.removeAttrs attrs ["packageOverrides"]
-          // { inherit src packageJSON yarnLock workspaceDependencies; }
-          // lib.attrByPath [name] {} packageOverrides
-        );
-      })
-      packagePaths
-    );
-  in packages;
-
-  mkYarnPackage = {
-    name ? null,
-    src,
-    packageJSON ? src + "/package.json",
-    yarnLock ? src + "/yarn.lock",
-    yarnNix ? mkYarnNix { inherit yarnLock; },
-    yarnFlags ? defaultYarnFlags,
-    yarnPreBuild ? "",
-    pkgConfig ? {},
-    extraBuildInputs ? [],
-    publishBinsFor ? null,
-    workspaceDependencies ? [], # List of yarnPackages
-    ...
-  }@attrs:
-    let
-      package = lib.importJSON packageJSON;
-      pname = package.name;
-      safeName = reformatPackageName pname;
-      version = package.version or attrs.version;
-      baseName = unlessNull name "${safeName}-${version}";
-
-      workspaceDependenciesTransitive = lib.unique (
-        (lib.flatten (builtins.map (dep: dep.workspaceDependencies) workspaceDependencies))
-        ++ workspaceDependencies
-      );
-
-      deps = mkYarnModules {
-        name = "${safeName}-modules-${version}";
-        preBuild = yarnPreBuild;
-        workspaceDependencies = workspaceDependenciesTransitive;
-        inherit packageJSON pname version yarnLock yarnNix yarnFlags pkgConfig;
-      };
-
-      publishBinsFor_ = unlessNull publishBinsFor [pname];
-
-      linkDirFunction = ''
-        linkDirToDirLinks() {
-          target=$1
-          if [ ! -f "$target" ]; then
-            mkdir -p "$target"
-          elif [ -L "$target" ]; then
-            local new=$(mktemp -d)
-            trueSource=$(realpath "$target")
-            if [ "$(ls $trueSource | wc -l)" -gt 0 ]; then
-              ln -s $trueSource/* $new/
-            fi
-            rm -r "$target"
-            mv "$new" "$target"
-          fi
-        }
-      '';
-
-      workspaceDependencyCopy = lib.concatMapStringsSep "\n"
-        (dep: ''
-          # ensure any existing scope directory is not a symlink
-          linkDirToDirLinks "$(dirname node_modules/${dep.pname})"
-          mkdir -p "deps/${dep.pname}"
-          tar -xf "${dep}/tarballs/${dep.name}.tgz" --directory "deps/${dep.pname}" --strip-components=1
-          if [ ! -e "deps/${dep.pname}/node_modules" ]; then
-            ln -s "${deps}/deps/${dep.pname}/node_modules" "deps/${dep.pname}/node_modules"
-          fi
-        '')
-        workspaceDependenciesTransitive;
-
-    in stdenv.mkDerivation (builtins.removeAttrs attrs ["pkgConfig" "workspaceDependencies"] // {
-      inherit src pname;
-
-      name = baseName;
-
-      buildInputs = [ yarn nodejs rsync ] ++ extraBuildInputs;
-
-      node_modules = deps + "/node_modules";
-
-      configurePhase = attrs.configurePhase or ''
-        runHook preConfigure
-
-        for localDir in npm-packages-offline-cache node_modules; do
-          if [[ -d $localDir || -L $localDir ]]; then
-            echo "$localDir dir present. Removing."
-            rm -rf $localDir
-          fi
-        done
-
-        # move convent of . to ./deps/${pname}
-        mv $PWD $NIX_BUILD_TOP/temp
-        mkdir -p "$PWD/deps/${pname}"
-        rm -fd "$PWD/deps/${pname}"
-        mv $NIX_BUILD_TOP/temp "$PWD/deps/${pname}"
-        cd $PWD
-
-        if [ -d ${deps}/deps/${pname}/node_modules ]; then
-          cp -r ${deps}/deps/${pname}/node_modules "deps/${pname}/node_modules"
-          chmod -R +w "deps/${pname}/node_modules"
-        fi
-        cp -r $node_modules node_modules
-        chmod -R +w node_modules
-
-        ${linkDirFunction}
-
-        linkDirToDirLinks "$(dirname node_modules/${pname})"
-
-        ${workspaceDependencyCopy}
-
-        # Help yarn commands run in other phases find the package
-        echo "--cwd deps/${pname}" > .yarnrc
-        runHook postConfigure
-      '';
-
-      # Replace this phase on frontend packages where only the generated
-      # files are an interesting output.
-      installPhase = attrs.installPhase or ''
-        runHook preInstall
-
-        mkdir -p $out/{bin,libexec/${pname}}
-        mv node_modules $out/libexec/${pname}/node_modules
-        mv deps $out/libexec/${pname}/deps
-
-        node ${./internal/fixup_bin.js} $out/bin $out/libexec/${pname}/node_modules ${lib.concatStringsSep " " publishBinsFor_}
-
-        runHook postInstall
-      '';
-
-      doDist = true;
-
-      distPhase = attrs.distPhase or ''
-        # pack command ignores cwd option
-        rm -f .yarnrc
-        cd $out/libexec/${pname}/deps/${pname}
-        mkdir -p $out/tarballs/
-        yarn pack --offline --ignore-scripts --filename $out/tarballs/${baseName}.tgz
-      '';
-
-      passthru = {
-        inherit pname package packageJSON deps;
-        workspaceDependencies = workspaceDependenciesTransitive;
-      } // (attrs.passthru or {});
-
-      meta = {
-        inherit (nodejs.meta) platforms;
-        description = packageJSON.description or "";
-        homepage = packageJSON.homepage or "";
-        version = packageJSON.version or "";
-        license = if packageJSON ? license then spdxLicense packageJSON.license else "";
-      } // (attrs.meta or {});
-    });
-
   yarn2nix = mkYarnPackage {
     src =
       let
-        src = ./.;
+        inherit src;
 
         mkFilter = { dirsToInclude, filesToInclude, root }: path: type:
           let
@@ -401,7 +42,7 @@ in rec {
     yarnFlags = defaultYarnFlags ++ ["--production=true"];
 
     buildPhase = ''
-      source ${./nix/expectShFunctions.sh}
+      source ${./expectShFunctions.sh}
 
       expectFilePresent ./node_modules/.yarn-integrity
 

tests/duplicate-pkgs/default.nix

@@ -1,6 +1,6 @@
-{ yarn2nix }:
+{ mkYarnPackage }:
 
-yarn2nix.mkYarnPackage {
+mkYarnPackage {
   src = ./.;
   buildPhase = ''
     source ${../../nix/expectShFunctions.sh}