JSON alongside binary proto serialization test data

This makes the proto serializer characterisation test data be
accompanied by JSON data.

This is arguably useful for a reasons:

- The JSON data is human-readable while the binary data is not, so it
  provides some indication of what the test data means beyond the C++
  literals.

- The JSON data is language-agnostic, and so can be used to quickly rig
  up tests for implementation in other languages, without having source
  code literals at all (just go back and forth between the JSON and the
  binary).

- Even though we have no concrete plans to place the binary protocol 1-1
  or with JSON, it is still nice to ensure that the JSON serializers and
  binary protocols have (near) equal coverage over data types, to help
  ensure we didn't forget a JSON (de)serializer.

Author: Ericson2314

src/libstore-test-support/include/nix/store/tests/protocol.hh

@@ -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

src/libstore-tests/common-protocol.cc

@@ -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(

src/libstore-tests/data/common-protocol/content-address.json

@@ -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"
+  }
+]

src/libstore-tests/data/common-protocol/drv-output.json

@@ -0,0 +1,4 @@
+[
+  "sha256:15e3c560894cbb27085cf65b5a2ecb18488c999497f4531b6907a7581ce6d527!baz",
+  "sha256:6f869f9ea2823bda165e06076fd0de4366dead2c0e8d2dbbad277d4f15c373f5!quux"
+]

src/libstore-tests/data/common-protocol/optional-content-address.json

@@ -0,0 +1,11 @@
+[
+  null,
+  {
+    "hash": {
+      "algorithm": "sha1",
+      "format": "base64",
+      "hash": "gGemBoenViNZM3hiwqns/Fgzqwo="
+    },
+    "method": "flat"
+  }
+]

src/libstore-tests/data/common-protocol/optional-store-path.json

@@ -0,0 +1,4 @@
+[
+  null,
+  "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo-bar"
+]

src/libstore-tests/data/common-protocol/realisation-with-deps.json

@@ -0,0 +1,13 @@
+[
+  {
+    "dependentRealisations": {
+      "sha256:6f869f9ea2823bda165e06076fd0de4366dead2c0e8d2dbbad277d4f15c373f5!quux": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo"
+    },
+    "id": "sha256:15e3c560894cbb27085cf65b5a2ecb18488c999497f4531b6907a7581ce6d527!baz",
+    "outPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo",
+    "signatures": [
+      "asdf",
+      "qwer"
+    ]
+  }
+]

src/libstore-tests/data/common-protocol/realisation.json

@@ -0,0 +1,17 @@
+[
+  {
+    "dependentRealisations": {},
+    "id": "sha256:15e3c560894cbb27085cf65b5a2ecb18488c999497f4531b6907a7581ce6d527!baz",
+    "outPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo",
+    "signatures": []
+  },
+  {
+    "dependentRealisations": {},
+    "id": "sha256:15e3c560894cbb27085cf65b5a2ecb18488c999497f4531b6907a7581ce6d527!baz",
+    "outPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo",
+    "signatures": [
+      "asdf",
+      "qwer"
+    ]
+  }
+]

src/libstore-tests/data/common-protocol/set.json

@@ -0,0 +1,22 @@
+[
+  [],
+  [
+    ""
+  ],
+  [
+    "",
+    "bar",
+    "foo"
+  ],
+  [
+    [],
+    [
+      ""
+    ],
+    [
+      "",
+      "1",
+      "2"
+    ]
+  ]
+]

src/libstore-tests/data/common-protocol/store-path.json

@@ -0,0 +1,4 @@
+[
+  "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo",
+  "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo-bar"
+]