Add StoreReference::render

This will be needed for the next step.

Also allows us to write round trip tests.

.clang-format

@@ -15,7 +15,7 @@ SpaceAfterCStyleCast: true
 SpaceAfterTemplateKeyword: false
 AccessModifierOffset: -4
 AlignAfterOpenBracket: AlwaysBreak
-AlignEscapedNewlines: DontAlign
+AlignEscapedNewlines: Left
 ColumnLimit: 120
 BreakStringLiterals: false
 BitFieldColonSpacing: None

maintainers/flake-module.nix

@@ -17,7 +17,8 @@
       excludes = [
         # We don't want to format test data
         # ''tests/(?!nixos/).*\.nix''
-        ''^tests/.*''
+        ''^tests/functional/.*$''
+        ''^tests/unit/[^/]*/data/.*$''
 
         # Don't format vendored code
         ''^src/toml11/.*''
@@ -426,6 +427,69 @@
         ''^src/nix/upgrade-nix\.cc$''
         ''^src/nix/verify\.cc$''
         ''^src/nix/why-depends\.cc$''
+
+        ''^tests/nixos/ca-fd-leak/sender\.c''
+        ''^tests/nixos/ca-fd-leak/smuggler\.c''
+        ''^tests/unit/libexpr-support/tests/libexpr\.hh''
+        ''^tests/unit/libexpr-support/tests/value/context\.cc''
+        ''^tests/unit/libexpr-support/tests/value/context\.hh''
+        ''^tests/unit/libexpr/derived-path\.cc''
+        ''^tests/unit/libexpr/error_traces\.cc''
+        ''^tests/unit/libexpr/eval\.cc''
+        ''^tests/unit/libexpr/flake/flakeref\.cc''
+        ''^tests/unit/libexpr/flake/url-name\.cc''
+        ''^tests/unit/libexpr/json\.cc''
+        ''^tests/unit/libexpr/main\.cc''
+        ''^tests/unit/libexpr/primops\.cc''
+        ''^tests/unit/libexpr/search-path\.cc''
+        ''^tests/unit/libexpr/trivial\.cc''
+        ''^tests/unit/libexpr/value/context\.cc''
+        ''^tests/unit/libexpr/value/print\.cc''
+        ''^tests/unit/libfetchers/public-key\.cc''
+        ''^tests/unit/libstore-support/tests/derived-path\.cc''
+        ''^tests/unit/libstore-support/tests/derived-path\.hh''
+        ''^tests/unit/libstore-support/tests/libstore\.hh''
+        ''^tests/unit/libstore-support/tests/nix_api_store\.hh''
+        ''^tests/unit/libstore-support/tests/outputs-spec\.cc''
+        ''^tests/unit/libstore-support/tests/outputs-spec\.hh''
+        ''^tests/unit/libstore-support/tests/path\.cc''
+        ''^tests/unit/libstore-support/tests/path\.hh''
+        ''^tests/unit/libstore-support/tests/protocol\.hh''
+        ''^tests/unit/libstore/common-protocol\.cc''
+        ''^tests/unit/libstore/content-address\.cc''
+        ''^tests/unit/libstore/derivation\.cc''
+        ''^tests/unit/libstore/derived-path\.cc''
+        ''^tests/unit/libstore/downstream-placeholder\.cc''
+        ''^tests/unit/libstore/machines\.cc''
+        ''^tests/unit/libstore/nar-info-disk-cache\.cc''
+        ''^tests/unit/libstore/nar-info\.cc''
+        ''^tests/unit/libstore/outputs-spec\.cc''
+        ''^tests/unit/libstore/path-info\.cc''
+        ''^tests/unit/libstore/path\.cc''
+        ''^tests/unit/libstore/serve-protocol\.cc''
+        ''^tests/unit/libstore/worker-protocol\.cc''
+        ''^tests/unit/libutil-support/tests/characterization\.hh''
+        ''^tests/unit/libutil-support/tests/hash\.cc''
+        ''^tests/unit/libutil-support/tests/hash\.hh''
+        ''^tests/unit/libutil/args\.cc''
+        ''^tests/unit/libutil/canon-path\.cc''
+        ''^tests/unit/libutil/chunked-vector\.cc''
+        ''^tests/unit/libutil/closure\.cc''
+        ''^tests/unit/libutil/compression\.cc''
+        ''^tests/unit/libutil/config\.cc''
+        ''^tests/unit/libutil/file-content-address\.cc''
+        ''^tests/unit/libutil/git\.cc''
+        ''^tests/unit/libutil/hash\.cc''
+        ''^tests/unit/libutil/hilite\.cc''
+        ''^tests/unit/libutil/json-utils\.cc''
+        ''^tests/unit/libutil/logging\.cc''
+        ''^tests/unit/libutil/lru-cache\.cc''
+        ''^tests/unit/libutil/pool\.cc''
+        ''^tests/unit/libutil/references\.cc''
+        ''^tests/unit/libutil/suggestions\.cc''
+        ''^tests/unit/libutil/tests\.cc''
+        ''^tests/unit/libutil/url\.cc''
+        ''^tests/unit/libutil/xml-writer\.cc''
       ];
     };
 

src/libstore/store-reference.cc

@@ -4,6 +4,7 @@
 #include "url.hh"
 #include "store-reference.hh"
 #include "file-system.hh"
+#include "util.hh"
 
 namespace nix {
 
@@ -17,6 +18,29 @@ static bool isNonUriPath(const std::string & spec)
         && spec.find("/") != std::string::npos;
 }
 
+std::string StoreReference::render() const
+{
+    std::string res;
+
+    std::visit(
+        overloaded{
+            [&](const StoreReference::Auto &) { res = "auto"; },
+            [&](const StoreReference::Specified & g) {
+                res = g.scheme;
+                res += "://";
+                res += g.authority;
+            },
+        },
+        variant);
+
+    if (!params.empty()) {
+        res += "?";
+        res += encodeQuery(params);
+    }
+
+    return res;
+}
+
 StoreReference StoreReference::parse(const std::string & uri, const StoreReference::Params & extraParams)
 {
     auto params = extraParams;

src/libstore/store-reference.hh

@@ -58,7 +58,7 @@ struct StoreReference
     struct Specified
     {
         std::string scheme;
-        std::string authority;
+        std::string authority = "";
 
         bool operator==(const Specified & rhs) const = default;
         auto operator<=>(const Specified & rhs) const = default;
@@ -73,6 +73,14 @@ struct StoreReference
     bool operator==(const StoreReference & rhs) const = default;
     auto operator<=>(const StoreReference & rhs) const = default;
 
+    /**
+     * Render the whole store reference as a URI, including parameters.
+     */
+    std::string render() const;
+
+    /**
+     * Parse a URI into a store reference.
+     */
     static StoreReference parse(const std::string & uri, const Params & extraParams = Params{});
 };
 

src/libutil/url.hh

@@ -33,6 +33,8 @@ std::string percentEncode(std::string_view s, std::string_view keep="");
 
 std::map<std::string, std::string> decodeQuery(const std::string & query);
 
+std::string encodeQuery(const std::map<std::string, std::string> & query);
+
 ParsedURL parseURL(const std::string & url);
 
 /**

tests/unit/libstore/data/store-reference/auto.txt

@@ -0,0 +1 @@
+auto

tests/unit/libstore/data/store-reference/auto_param.txt

@@ -0,0 +1 @@
+auto?root=/foo/bar/baz

tests/unit/libstore/data/store-reference/local_1.txt

@@ -0,0 +1 @@
+local://?root=/foo/bar/baz

tests/unit/libstore/data/store-reference/local_2.txt

@@ -0,0 +1 @@
+local:///foo/bar/baz?trusted=true

tests/unit/libstore/data/store-reference/local_shorthand_1.txt

@@ -0,0 +1 @@
+local?root=/foo/bar/baz

tests/unit/libstore/data/store-reference/local_shorthand_2.txt

@@ -0,0 +1 @@
+/foo/bar/baz?trusted=true

tests/unit/libstore/data/store-reference/ssh.txt

@@ -0,0 +1 @@
+ssh://localhost

tests/unit/libstore/data/store-reference/unix.txt

@@ -0,0 +1 @@
+unix://?max-connections=7&trusted=true

tests/unit/libstore/data/store-reference/unix_shorthand.txt

@@ -0,0 +1 @@
+daemon?max-connections=7&trusted=true

tests/unit/libstore/store-reference.cc

@@ -0,0 +1,123 @@
+#include <nlohmann/json.hpp>
+#include <gtest/gtest.h>
+
+#include "file-system.hh"
+#include "store-reference.hh"
+
+#include "tests/characterization.hh"
+#include "tests/libstore.hh"
+
+namespace nix {
+
+using nlohmann::json;
+
+class StoreReferenceTest : public CharacterizationTest, public LibStoreTest
+{
+    Path unitTestData = getUnitTestData() + "/store-reference";
+
+    Path goldenMaster(PathView testStem) const override
+    {
+        return unitTestData + "/" + testStem + ".txt";
+    }
+};
+
+#define URI_TEST_READ(STEM, OBJ)                         \
+  TEST_F(StoreReferenceTest, PathInfo_##STEM##_from_uri) \
+  {                                                      \
+    readTest(#STEM, ([&](const auto & encoded) {         \
+           StoreReference expected = OBJ;                \
+           auto got = StoreReference::parse(encoded);    \
+           ASSERT_EQ(got, expected);                     \
+             }));                                        \
+  }
+
+#define URI_TEST_WRITE(STEM, OBJ)                                                           \
+  TEST_F(StoreReferenceTest, PathInfo_##STEM##_to_uri)                                      \
+  {                                                                                         \
+    writeTest(                                                                              \
+        #STEM,                                                                              \
+        [&]() -> StoreReference { return OBJ; },                                            \
+        [](const auto & file) { return StoreReference::parse(readFile(file)); },            \
+        [](const auto & file, const auto & got) { return writeFile(file, got.render()); }); \
+  }
+
+#define URI_TEST(STEM, OBJ) \
+  URI_TEST_READ(STEM, OBJ)  \
+  URI_TEST_WRITE(STEM, OBJ)
+
+URI_TEST(
+    auto,
+    (StoreReference{
+        .variant = StoreReference::Auto{},
+        .params = {},
+    }))
+
+URI_TEST(
+    auto_param,
+    (StoreReference{
+        .variant = StoreReference::Auto{},
+        .params =
+            {
+                {"root", "/foo/bar/baz"},
+            },
+    }))
+
+static StoreReference localExample_1{
+    .variant =
+        StoreReference::Specified{
+            .scheme = "local",
+        },
+    .params =
+        {
+            {"root", "/foo/bar/baz"},
+        },
+};
+
+static StoreReference localExample_2{
+    .variant =
+        StoreReference::Specified{
+            .scheme = "local",
+            .authority = "/foo/bar/baz",
+        },
+    .params =
+        {
+            {"trusted", "true"},
+        },
+};
+
+URI_TEST(local_1, localExample_1)
+
+URI_TEST(local_2, localExample_2)
+
+URI_TEST_READ(local_shorthand_1, localExample_1)
+
+URI_TEST_READ(local_shorthand_2, localExample_2)
+
+static StoreReference unixExample{
+    .variant =
+        StoreReference::Specified{
+            .scheme = "unix",
+        },
+    .params =
+        {
+            {"max-connections", "7"},
+            {"trusted", "true"},
+        },
+};
+
+URI_TEST(unix, unixExample)
+
+URI_TEST_READ(unix_shorthand, unixExample)
+
+URI_TEST(
+    ssh,
+    (StoreReference{
+        .variant =
+            StoreReference::Specified{
+                .scheme = "ssh",
+                .authority = "localhost",
+            },
+        .params = {},
+    }))
+
+}