Add tests for using cargoExtraArgs

* In this case, we set up a crate with various non-default features and
  ensure that we can correctly influence the cargo build by passing in
  the appropriate `--feature` flag

tests/compilesFresh.nix

@@ -3,10 +3,10 @@
 , jq
 }:
 
-src: expected:
+src: expected: args:
 let
   runCargoAndCheckFreshness = cmd: ''
-    cargo ${cmd} --workspace --release --message-format json-diagnostic-short >${cmd}out
+    cargo ${cmd} --workspace --release --message-format json-diagnostic-short ${args.cargoExtraArgs or ""} >${cmd}out
 
     filter='select(.reason == "compiler-artifact" and .fresh != true) | .target.name'
     builtTargets="$(jq -r "$filter" <${cmd}out | sort -u)"
@@ -19,13 +19,13 @@ let
     fi
   '';
 in
-buildWithCargo {
+buildWithCargo (args // {
   inherit src;
   doCopyTargetToOutput = false;
 
   # NB: explicit call here so that the buildDepsOnly call
   # doesn't inherit our build commands
-  cargoArtifacts = buildDepsOnly { inherit src; };
+  cargoArtifacts = buildDepsOnly (args // { inherit src; });
 
   nativeBuildInputs = [ jq ];
 
@@ -49,4 +49,4 @@ buildWithCargo {
   installPhase = ''
     touch $out
   '';
-}
+})

tests/default.nix

@@ -17,7 +17,7 @@ pkgs.lib.makeScope myLib.newScope (self:
     cmpCleanCargoTomlComplex = self.cmpCleanCargoToml ./cleanCargoToml/complex;
 
     compilesFresh = callPackage ./compilesFresh.nix { };
-    compilesFreshSimple = self.compilesFresh ./simple "simple";
+    compilesFreshSimple = self.compilesFresh ./simple "simple" { };
     compilesFreshOverlappingTargets = self.compilesFresh
       ./overlapping-targets
       (builtins.concatStringsSep "\n" [
@@ -25,7 +25,8 @@ pkgs.lib.makeScope myLib.newScope (self:
         "baz"
         "foo"
         "overlapping-targets"
-      ]);
+      ])
+      { };
 
     customCargoTargetDirectory =
       let
@@ -45,65 +46,7 @@ pkgs.lib.makeScope myLib.newScope (self:
       src = ./various-targets;
     };
 
-    featuresDefault =
-      let
-        crate = myLib.buildPackage {
-          src = ./features;
-        };
-      in
-      pkgs.runCommand "featuresDefault" { } ''
-        set -x
-        [[ "hello" == "$(${crate}/bin/features)" ]]
-        touch $out
-      '';
-
-    featuresFoo =
-      let
-        crate = myLib.buildPackage {
-          src = ./features;
-          cargoExtraArgs = "--features foo";
-        };
-      in
-      pkgs.runCommand "featuresFoo" { } ''
-        [[ "$(echo -e 'hello\nfoo')" == "$(${crate}/bin/features)" ]]
-        touch $out
-      '';
-
-    featuresBar =
-      let
-        crate = myLib.buildPackage {
-          src = ./features;
-          cargoExtraArgs = "--features bar";
-        };
-      in
-      pkgs.runCommand "featuresBar" { } ''
-        [[ "$(echo -e 'hello\nbar')" == "$(${crate}/bin/features)" ]]
-        touch $out
-      '';
-
-    featuresFooBar =
-      let
-        crate = myLib.buildPackage {
-          src = ./features;
-          cargoExtraArgs = "--features 'foo bar'";
-        };
-      in
-      pkgs.runCommand "featuresFoo" { } ''
-        [[ "$(echo -e 'hello\nfoo\nbar')" == "$(${crate}/bin/features)" ]]
-        touch $out
-      '';
-
-    featuresAll =
-      let
-        crate = myLib.buildPackage {
-          src = ./features;
-          cargoExtraArgs = "--all-features";
-        };
-      in
-      pkgs.runCommand "featuresAll" { } ''
-        [[ "$(echo -e 'hello\nfoo\nbar')" == "$(${crate}/bin/features)" ]]
-        touch $out
-      '';
+    features = callPackage ./features { };
 
     manyLibs = myLib.buildPackage {
       src = ./with-libs;

tests/features/Cargo.lock

@@ -1,7 +0,0 @@
-# This file is automatically @generated by Cargo.
-# It is not intended for manual editing.
-version = 3
-
-[[package]]
-name = "features"
-version = "0.1.0"

tests/features/Cargo.toml

@@ -1,9 +0,0 @@
-[package]
-name = "features"
-version = "0.1.0"
-edition = "2021"
-
-[features]
-default = []
-foo = []
-bar = []

tests/features/default.nix

@@ -0,0 +1,62 @@
+{ buildPackage
+, compilesFresh
+, lib
+, linkFarmFromDrvs
+, runCommand
+}:
+
+let
+  mkTests = { name, cargoExtraArgs, runResult }:
+    let
+      crate = buildPackage {
+        inherit cargoExtraArgs name;
+        src = ./features;
+      };
+    in
+    [
+      crate
+
+      (compilesFresh ./features "features" {
+        inherit cargoExtraArgs;
+        name = "${name}CompilesFresh";
+      })
+
+      (runCommand "${name}Run" { } ''
+        [[ "hello${runResult}" == "$(${crate}/bin/features)" ]]
+        touch $out
+      '')
+    ];
+
+  tests = [
+    (mkTests {
+      name = "default";
+      cargoExtraArgs = "";
+      runResult = "";
+    })
+
+    (mkTests {
+      name = "foo";
+      cargoExtraArgs = "--features foo";
+      runResult = "\nfoo";
+    })
+
+    (mkTests {
+      name = "bar";
+      cargoExtraArgs = "--features bar";
+      runResult = "\nbar";
+    })
+
+    (mkTests {
+      name = "fooBar";
+      cargoExtraArgs = "--features 'foo bar'";
+      runResult = "\nfoo\nbar";
+    })
+
+    (mkTests {
+      name = "all";
+      cargoExtraArgs = "--all-features";
+      runResult = "\nfoo\nbar";
+    })
+  ];
+in
+linkFarmFromDrvs "features" (lib.flatten tests)

tests/features/features/Cargo.lock

@@ -0,0 +1,49 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aho-corasick"
+version = "0.7.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e37cfd5e7657ada45f742d6e99ca5788580b5c529dc78faf11ece6dc702656f"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "features"
+version = "0.1.0"
+dependencies = [
+ "libc",
+ "regex",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.112"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b03d17f364a3a042d5e5d46b053bbbf82c92c9430c592dd4c064dc6ee997125"
+
+[[package]]
+name = "memchr"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
+
+[[package]]
+name = "regex"
+version = "1.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"

tests/features/features/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "features"
+version = "0.1.0"
+edition = "2021"
+
+[features]
+default = []
+foo = ["libc"]
+bar = ["regex"]
+
+[dependencies]
+libc = { version = "*", optional = true }
+regex = { version = "*", optional = true }