1 files changed, 57 insertions, 0 deletions
diff --git a/pkgs/build-support/dart/pub2nix/package-config.nix b/pkgs/build-support/dart/pub2nix/package-config.nix
new file mode 100644
index 0000000000000..29c6bac6b2cdf
--- /dev/null
+++ b/pkgs/build-support/dart/pub2nix/package-config.nix
@@ -0,0 +1,57 @@
+{ lib
+, runCommand
+, jq
+, yq
+}:
+
+{ pname ? null
+
+  # A list of dependency package names.
+, dependencies
+
+  # An attribute set of package names to sources.
+, dependencySources
+}:
+
+let
+  packages = lib.getAttrs dependencies dependencySources;
+in
+(runCommand "${lib.optionalString (pname != null) "${pname}-"}package-config.json" {
+  inherit packages;
+
+  nativeBuildInputs = [ jq yq ];
+
+  __structuredAttrs = true;
+}) ''
+  declare -A packages
+  while IFS='=' read -r name path; do
+    packages["$name"]="$path"
+  done < <(jq -r '.packages | to_entries | map("\(.key)=\(.value)") | .[]' "$NIX_ATTRS_JSON_FILE")
+
+  jq > "$out" --slurp '{
+    configVersion: 2,
+    generator: "nixpkgs",
+    packages: .,
+  }' <(for package in "''${!packages[@]}"; do
+      languageConstraint="$(yq -r .environment.sdk "''${packages["$package"]}/pubspec.yaml")"
+      if [[ "$languageConstraint" =~ ^[[:space:]]*(\^|>=|>|)[[:space:]]*([[:digit:]]+\.[[:digit:]]+)\.[[:digit:]]+.*$ ]]; then
+        languageVersionJson="\"''${BASH_REMATCH[2]}\""
+      elif [ "$languageConstraint" = 'any' ]; then
+        languageVersionJson='null'
+      else
+        # https://github.com/dart-lang/pub/blob/68dc2f547d0a264955c1fa551fa0a0e158046494/lib/src/language_version.dart#L106C35-L106C35
+        languageVersionJson='"2.7"'
+      fi
+
+      jq --null-input \
+        --arg name "$package" \
+        --arg path "''${packages["$package"]}" \
+        --argjson languageVersion "$languageVersionJson" \
+        '{
+          name: $name,
+          rootUri: "file://\($path)",
+          packageUri: "lib/",
+          languageVersion: $languageVersion,
+        }'
+    done)
+''