From fb028ae701b34b3687600386e6556058d865124d Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Thu, 13 Feb 2025 00:52:05 -0500
Subject: [PATCH] Don't do store operations in `*DerivedPath::toJSON`

It is inappropriate to do "real work" when converting plain old data to
JSON.
---
 src/libstore/derived-path.cc                  | 47 ++++++-------------
 .../include/nix/store/derived-path.hh         |  8 ++--
 tests/functional/build-dry.sh                 | 15 ++----
 3 files changed, 22 insertions(+), 48 deletions(-)

diff --git a/src/libstore/derived-path.cc b/src/libstore/derived-path.cc
index 6186f0582..658be5801 100644
--- a/src/libstore/derived-path.cc
+++ b/src/libstore/derived-path.cc
@@ -41,49 +41,30 @@ nlohmann::json DerivedPath::Opaque::toJSON(const StoreDirConfig & store) const
     return store.printStorePath(path);
 }
 
-nlohmann::json SingleDerivedPath::Built::toJSON(Store & store) const {
-    nlohmann::json res;
-    res["drvPath"] = drvPath->toJSON(store);
-    // Fallback for the input-addressed derivation case: We expect to always be
-    // able to print the output paths, so let’s do it
-    // FIXME try-resolve on drvPath
-    const auto outputMap = store.queryPartialDerivationOutputMap(resolveDerivedPath(store, *drvPath));
-    res["output"] = output;
-    auto outputPathIter = outputMap.find(output);
-    if (outputPathIter == outputMap.end())
-        res["outputPath"] = nullptr;
-    else if (std::optional p = outputPathIter->second)
-        res["outputPath"] = store.printStorePath(*p);
-    else
-        res["outputPath"] = nullptr;
-    return res;
+nlohmann::json SingleDerivedPath::Built::toJSON(const StoreDirConfig & store) const
+{
+    return nlohmann::json{
+        {"drvPath", drvPath->toJSON(store)},
+        {"output", output},
+    };
 }
 
-nlohmann::json DerivedPath::Built::toJSON(Store & store) const {
-    nlohmann::json res;
-    res["drvPath"] = drvPath->toJSON(store);
-    // Fallback for the input-addressed derivation case: We expect to always be
-    // able to print the output paths, so let’s do it
-    // FIXME try-resolve on drvPath
-    const auto outputMap = store.queryPartialDerivationOutputMap(resolveDerivedPath(store, *drvPath));
-    for (const auto & [output, outputPathOpt] : outputMap) {
-        if (!outputs.contains(output)) continue;
-        if (outputPathOpt)
-            res["outputs"][output] = store.printStorePath(*outputPathOpt);
-        else
-            res["outputs"][output] = nullptr;
-    }
-    return res;
+nlohmann::json DerivedPath::Built::toJSON(const StoreDirConfig & store) const
+{
+    return nlohmann::json{
+        {"drvPath", drvPath->toJSON(store)},
+        {"outputs", outputs},
+    };
 }
 
-nlohmann::json SingleDerivedPath::toJSON(Store & store) const
+nlohmann::json SingleDerivedPath::toJSON(const StoreDirConfig & store) const
 {
     return std::visit([&](const auto & buildable) {
         return buildable.toJSON(store);
     }, raw());
 }
 
-nlohmann::json DerivedPath::toJSON(Store & store) const
+nlohmann::json DerivedPath::toJSON(const StoreDirConfig & store) const
 {
     return std::visit([&](const auto & buildable) {
         return buildable.toJSON(store);
diff --git a/src/libstore/include/nix/store/derived-path.hh b/src/libstore/include/nix/store/derived-path.hh
index 64189bd41..18a722ba4 100644
--- a/src/libstore/include/nix/store/derived-path.hh
+++ b/src/libstore/include/nix/store/derived-path.hh
@@ -77,7 +77,7 @@ struct SingleDerivedPathBuilt {
         const StoreDirConfig & store, ref<const SingleDerivedPath> drvPath,
         OutputNameView outputs,
         const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
-    nlohmann::json toJSON(Store & store) const;
+    nlohmann::json toJSON(const StoreDirConfig & store) const;
 
     bool operator == (const SingleDerivedPathBuilt &) const noexcept;
     std::strong_ordering operator <=> (const SingleDerivedPathBuilt &) const noexcept;
@@ -151,7 +151,7 @@ struct SingleDerivedPath : _SingleDerivedPathRaw {
         const StoreDirConfig & store,
         std::string_view,
         const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
-    nlohmann::json toJSON(Store & store) const;
+    nlohmann::json toJSON(const StoreDirConfig & store) const;
 };
 
 static inline ref<SingleDerivedPath> makeConstantStorePathRef(StorePath drvPath)
@@ -204,7 +204,7 @@ struct DerivedPathBuilt {
         const StoreDirConfig & store, ref<const SingleDerivedPath>,
         std::string_view,
         const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
-    nlohmann::json toJSON(Store & store) const;
+    nlohmann::json toJSON(const StoreDirConfig & store) const;
 
     bool operator == (const DerivedPathBuilt &) const noexcept;
     // TODO libc++ 16 (used by darwin) missing `std::set::operator <=>`, can't do yet.
@@ -285,7 +285,7 @@ struct DerivedPath : _DerivedPathRaw {
      */
     static DerivedPath fromSingle(const SingleDerivedPath &);
 
-    nlohmann::json toJSON(Store & store) const;
+    nlohmann::json toJSON(const StoreDirConfig & store) const;
 };
 
 typedef std::vector<DerivedPath> DerivedPaths;
diff --git a/tests/functional/build-dry.sh b/tests/functional/build-dry.sh
index cff0f9a49..7d09c7f45 100755
--- a/tests/functional/build-dry.sh
+++ b/tests/functional/build-dry.sh
@@ -58,14 +58,7 @@ clearCache
 
 RES=$(nix build -f dependencies.nix --dry-run --json)
 
-if [[ -z "${NIX_TESTS_CA_BY_DEFAULT-}" ]]; then
-    echo "$RES" | jq '.[0] | [
-        (.drvPath | test("'"$NIX_STORE_DIR"'.*\\.drv")),
-        (.outputs.out | test("'"$NIX_STORE_DIR"'"))
-    ] | all'
-else
-    echo "$RES" | jq '.[0] | [
-        (.drvPath | test("'"$NIX_STORE_DIR"'.*\\.drv")),
-        .outputs.out == null
-    ] | all'
-fi
+echo "$RES" | jq '.[0] | [
+    (.drvPath | test("'"$NIX_STORE_DIR"'.*\\.drv")),
+    .outputs == [ "out" ]
+] | all'