chore: npm translator: optimizations and fixes

- don't use expensive replaceRootSources
- don't mess with sources, just use data from package-lock

src/subsystems/nodejs/translators/npm/default.nix

@@ -20,6 +20,7 @@
     moreutils,
     nodePackages,
     openssh,
+    python3,
     writeScriptBin,
     ...
   }:
@@ -32,6 +33,7 @@
       moreutils
       nodePackages.npm
       openssh
+      python3
     ]
     ''
       # accroding to the spec, the translator reads the input from a json file
@@ -42,6 +44,9 @@
       name=$(jq '.project.name' -c -r $jsonInput)
       version=$(jq '.project.version' -c -r $jsonInput)
       npmArgs=$(jq '.project.subsystemInfo.npmArgs' -c -r $jsonInput)
+      if [ "$npmArgs" == "null" ]; then
+        npmArgs=
+      fi
 
       if [ "$version" = "null" ]; then
         candidate="$name"
@@ -49,7 +54,6 @@
         candidate="$name@$version"
       fi
 
-
       pushd $TMPDIR
       newSource=$(pwd)
 
@@ -62,26 +66,14 @@
       # call package-lock translator
       ${subsystems.nodejs.translators.package-lock.translateBin} $TMPDIR/newJsonInput
 
-      # generate source info for main package
-      url=$(npm view $candidate dist.tarball)
-      hash=$(npm view $candidate dist.integrity)
-      echo "
-        {
-          \"type\": \"http\",
-          \"url\": \"$url\",
-          \"hash\": \"$hash\"
-        }
-      " > $TMPDIR/sourceInfo.json
+      # get resolved package version
+      export version=$(npm view $candidate version)
+
+      # set correct package version under `packages`
+      cat $outputFile \
+        | python3 ${./fixup-dream-lock.py} $TMPDIR/sourceInfo.json \
+        | sponge $outputFile
 
-      # add main package source info to dream-lock.json
-      ${apps.callNixWithD2N} eval --json "
-        with dream2nix.utils.dreamLock;
-        replaceRootSources {
-          dreamLock = l.fromJSON (l.readFile \"$outputFile\");
-          newSourceRoot = l.fromJSON (l.readFile \"$TMPDIR/sourceInfo.json\");
-        }
-      " \
-        | sponge "$outputFile"
     '';
 
   # inherit options from package-lock translator

src/subsystems/nodejs/translators/npm/fixup-dream-lock.py

@@ -0,0 +1,14 @@
+import json
+import os
+import sys
+
+lock = json.load(sys.stdin)
+version = os.environ.get('version')
+
+# set default package version correctly
+defaultPackage = lock['_generic']['defaultPackage']
+lock['_generic']['packages'] = {
+  defaultPackage: version
+}
+
+print(json.dumps(lock, indent=2))