NixOS · Mic92 · Nov 11, 2025 · Oct 30, 2025
@@ -6,6 +6,7 @@
 
 #include "nix/store/tests/libstore.hh"
 #include "nix/util/tests/characterization.hh"
+#include "nix/util/tests/json-characterization.hh"
 
 namespace nix {
 
@@ -16,12 +17,30 @@ class ProtoTest : public CharacterizationTest
 
     std::filesystem::path goldenMaster(std::string_view testStem) const override
     {
-        return unitTestData / (std::string{testStem + ".bin"});
+        return unitTestData / testStem;
     }
 
 public:
     Path storeDir = "/nix/store";
     StoreDirConfig store{storeDir};
+
+    /**
+     * Golden test for `T` JSON reading
+     */
+    template<typename T>
+    void readJsonTest(PathView testStem, const T & expected)
+    {
+        nix::readJsonTest(*this, testStem, expected);
+    }
+
+    /**
+     * Golden test for `T` JSON write
+     */
+    template<typename T>
+    void writeJsonTest(PathView testStem, const T & decoded)
+    {
+        nix::writeJsonTest(*this, testStem, decoded);
+    }
 };
 
 template<class Proto, const char * protocolDir>
@@ -34,7 +53,7 @@ public:
     template<typename T>
     void readProtoTest(PathView testStem, typename Proto::Version version, T expected)
     {
-        CharacterizationTest::readTest(testStem, [&](const auto & encoded) {
+        CharacterizationTest::readTest(std::string{testStem + ".bin"}, [&](const auto & encoded) {
             T got = ({
                 StringSource from{encoded};
                 Proto::template Serialise<T>::read(
@@ -55,7 +74,7 @@ public:
     template<typename T>
     void writeProtoTest(PathView testStem, typename Proto::Version version, const T & decoded)
     {
-        CharacterizationTest::writeTest(testStem, [&]() {
+        CharacterizationTest::writeTest(std::string{testStem + ".bin"}, [&]() {
             StringSink to;
             Proto::template Serialise<T>::write(
                 this->store,
@@ -69,14 +88,25 @@ public:
     }
 };
 
-#define VERSIONED_CHARACTERIZATION_TEST(FIXTURE, NAME, STEM, VERSION, VALUE) \
-    TEST_F(FIXTURE, NAME##_read)                                             \
-    {                                                                        \
-        readProtoTest(STEM, VERSION, VALUE);                                 \
-    }                                                                        \
-    TEST_F(FIXTURE, NAME##_write)                                            \
-    {                                                                        \
-        writeProtoTest(STEM, VERSION, VALUE);                                \
+#define VERSIONED_CHARACTERIZATION_TEST_NO_JSON(FIXTURE, NAME, STEM, VERSION, VALUE) \
+    TEST_F(FIXTURE, NAME##_read)                                                     \
+    {                                                                                \
+        readProtoTest(STEM, VERSION, VALUE);                                         \
+    }                                                                                \
+    TEST_F(FIXTURE, NAME##_write)                                                    \
+    {                                                                                \
+        writeProtoTest(STEM, VERSION, VALUE);                                        \
+    }
+
+#define VERSIONED_CHARACTERIZATION_TEST(FIXTURE, NAME, STEM, VERSION, VALUE)     \
+    VERSIONED_CHARACTERIZATION_TEST_NO_JSON(FIXTURE, NAME, STEM, VERSION, VALUE) \
+    TEST_F(FIXTURE, NAME##_json_read)                                            \
+    {                                                                            \
+        readJsonTest(STEM, VALUE);                                               \
+    }                                                                            \
+    TEST_F(FIXTURE, NAME##_json_write)                                           \
+    {                                                                            \
+        writeJsonTest(STEM, VALUE);                                              \
     }
 
 } // namespace nix
@@ -3,6 +3,7 @@
 #include <nlohmann/json.hpp>
 #include <gtest/gtest.h>
 
+#include "nix/util/json-utils.hh"
 #include "nix/store/common-protocol.hh"
 #include "nix/store/common-protocol-impl.hh"
 #include "nix/store/build-result.hh"
@@ -22,7 +23,7 @@ class CommonProtoTest : public ProtoTest<CommonProto, commonProtoDir>
     template<typename T>
     void readProtoTest(PathView testStem, const T & expected)
     {
-        CharacterizationTest::readTest(testStem, [&](const auto & encoded) {
+        CharacterizationTest::readTest(std::string{testStem + ".bin"}, [&](const auto & encoded) {
             T got = ({
                 StringSource from{encoded};
                 CommonProto::Serialise<T>::read(store, CommonProto::ReadConn{.from = from});
@@ -38,7 +39,7 @@ class CommonProtoTest : public ProtoTest<CommonProto, commonProtoDir>
     template<typename T>
     void writeProtoTest(PathView testStem, const T & decoded)
     {
-        CharacterizationTest::writeTest(testStem, [&]() -> std::string {
+        CharacterizationTest::writeTest(std::string{testStem + ".bin"}, [&]() -> std::string {
             StringSink to;
             CommonProto::Serialise<T>::write(store, CommonProto::WriteConn{.to = to}, decoded);
             return to.s;
@@ -54,6 +55,14 @@ class CommonProtoTest : public ProtoTest<CommonProto, commonProtoDir>
     TEST_F(CommonProtoTest, NAME##_write)        \
     {                                            \
         writeProtoTest(STEM, VALUE);             \
+    }                                            \
+    TEST_F(CommonProtoTest, NAME##_json_read)    \
+    {                                            \
+        readJsonTest(STEM, VALUE);               \
+    }                                            \
+    TEST_F(CommonProtoTest, NAME##_json_write)   \
+    {                                            \
+        writeJsonTest(STEM, VALUE);              \
     }
 
 CHARACTERIZATION_TEST(

@@ -0,0 +1,26 @@
+[
+  {
+    "hash": {
+      "algorithm": "sha256",
+      "format": "base64",
+      "hash": "+Xc9Ll6mcPltwaewrk/BAQ56Y3G5T//wzhKUc0zrYu0="
+    },
+    "method": "text"
+  },
+  {
+    "hash": {
+      "algorithm": "sha1",
+      "format": "base64",
+      "hash": "gGemBoenViNZM3hiwqns/Fgzqwo="
+    },
+    "method": "flat"
+  },
+  {
+    "hash": {
+      "algorithm": "sha256",
+      "format": "base64",
+      "hash": "EMIJ+giQ/gLIWoxmPKjno3zHZrxbGymgzGGyZvZBIdM="
+    },
+    "method": "nar"
+  }
+]
@@ -0,0 +1,4 @@
+[
+  "sha256:15e3c560894cbb27085cf65b5a2ecb18488c999497f4531b6907a7581ce6d527!baz",
+  "sha256:6f869f9ea2823bda165e06076fd0de4366dead2c0e8d2dbbad277d4f15c373f5!quux"
+]
@@ -0,0 +1,11 @@
+[
+  null,
+  {
+    "hash": {
+      "algorithm": "sha1",
+      "format": "base64",
+      "hash": "gGemBoenViNZM3hiwqns/Fgzqwo="
+    },
+    "method": "flat"
+  }
+]
@@ -0,0 +1,4 @@
+[
+  null,
+  "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo-bar"
+]
@@ -0,0 +1,13 @@
+[
+  {
+    "dependentRealisations": {
+      "sha256:6f869f9ea2823bda165e06076fd0de4366dead2c0e8d2dbbad277d4f15c373f5!quux": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo"
+    },
+    "id": "sha256:15e3c560894cbb27085cf65b5a2ecb18488c999497f4531b6907a7581ce6d527!baz",
+    "outPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo",
+    "signatures": [
+      "asdf",
+      "qwer"
+    ]
+  }
+]
@@ -0,0 +1,17 @@
+[
+  {
+    "dependentRealisations": {},
+    "id": "sha256:15e3c560894cbb27085cf65b5a2ecb18488c999497f4531b6907a7581ce6d527!baz",
+    "outPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo",
+    "signatures": []
+  },
+  {
+    "dependentRealisations": {},
+    "id": "sha256:15e3c560894cbb27085cf65b5a2ecb18488c999497f4531b6907a7581ce6d527!baz",
+    "outPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo",
+    "signatures": [
+      "asdf",
+      "qwer"
+    ]
+  }
+]
@@ -0,0 +1,22 @@
+[
+  [],
+  [
+    ""
+  ],
+  [
+    "",
+    "bar",
+    "foo"
+  ],
+  [
+    [],
+    [
+      ""
+    ],
+    [
+      "",
+      "1",
+      "2"
+    ]
+  ]
+]
@@ -0,0 +1,4 @@
+[
+  "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo",
+  "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo-bar"
+]
@@ -0,0 +1,7 @@
+[
+  "",
+  "hi",
+  "white rabbit",
+  "大白兔",
+  "oh no "
+]
@@ -0,0 +1,22 @@
+[
+  [],
+  [
+    ""
+  ],
+  [
+    "",
+    "foo",
+    "bar"
+  ],
+  [
+    [],
+    [
+      ""
+    ],
+    [
+      "",
+      "1",
+      "2"
+    ]
+  ]
+]
@@ -0,0 +1,28 @@
+[
+  {
+    "errorMsg": "no idea why",
+    "isNonDeterministic": false,
+    "startTime": 0,
+    "status": "OutputRejected",
+    "stopTime": 0,
+    "success": false,
+    "timesBuilt": 0
+  },
+  {
+    "errorMsg": "no idea why",
+    "isNonDeterministic": false,
+    "startTime": 0,
+    "status": "NotDeterministic",
+    "stopTime": 0,
+    "success": false,
+    "timesBuilt": 0
+  },
+  {
+    "builtOutputs": {},
+    "startTime": 0,
+    "status": "Built",
+    "stopTime": 0,
+    "success": true,
+    "timesBuilt": 0
+  }
+]
@@ -0,0 +1,28 @@
+[
+  {
+    "errorMsg": "no idea why",
+    "isNonDeterministic": false,
+    "startTime": 0,
+    "status": "OutputRejected",
+    "stopTime": 0,
+    "success": false,
+    "timesBuilt": 0
+  },
+  {
+    "errorMsg": "no idea why",
+    "isNonDeterministic": true,
+    "startTime": 30,
+    "status": "NotDeterministic",
+    "stopTime": 50,
+    "success": false,
+    "timesBuilt": 3
+  },
+  {
+    "builtOutputs": {},
+    "startTime": 30,
+    "status": "Built",
+    "stopTime": 50,
+    "success": true,
+    "timesBuilt": 0
+  }
+]
@@ -0,0 +1,41 @@
+[
+  {
+    "errorMsg": "no idea why",
+    "isNonDeterministic": false,
+    "startTime": 0,
+    "status": "OutputRejected",
+    "stopTime": 0,
+    "success": false,
+    "timesBuilt": 0
+  },
+  {
+    "errorMsg": "no idea why",
+    "isNonDeterministic": true,
+    "startTime": 30,
+    "status": "NotDeterministic",
+    "stopTime": 50,
+    "success": false,
+    "timesBuilt": 3
+  },
+  {
+    "builtOutputs": {
+      "bar": {
+        "dependentRealisations": {},
+        "id": "sha256:6f869f9ea2823bda165e06076fd0de4366dead2c0e8d2dbbad277d4f15c373f5!bar",
+        "outPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-bar",
+        "signatures": []
+      },
+      "foo": {
+        "dependentRealisations": {},
+        "id": "sha256:6f869f9ea2823bda165e06076fd0de4366dead2c0e8d2dbbad277d4f15c373f5!foo",
+        "outPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo",
+        "signatures": []
+      }
+    },
+    "startTime": 30,
+    "status": "Built",
+    "stopTime": 50,
+    "success": true,
+    "timesBuilt": 1
+  }
+]
@@ -0,0 +1,26 @@
+[
+  {
+    "hash": {
+      "algorithm": "sha256",
+      "format": "base64",
+      "hash": "+Xc9Ll6mcPltwaewrk/BAQ56Y3G5T//wzhKUc0zrYu0="
+    },
+    "method": "text"
+  },
+  {
+    "hash": {
+      "algorithm": "sha1",
+      "format": "base64",
+      "hash": "gGemBoenViNZM3hiwqns/Fgzqwo="
+    },
+    "method": "flat"
+  },
+  {
+    "hash": {
+      "algorithm": "sha256",
+      "format": "base64",
+      "hash": "EMIJ+giQ/gLIWoxmPKjno3zHZrxbGymgzGGyZvZBIdM="
+    },
+    "method": "nar"
+  }
+]
-Original file line number
+Diff line change
@@ -0,0 +1,22 @@
+    [
+      [],
+      [
+        ""
+      ],
+      [
+        "",
+        "bar",
+        "foo"
+      ],
+      [
+        [],
+        [
+          ""
+        ],
+        [
+          "",
+          "1",
+          "2"
+        ]
+      ]
+    ]