buildRustCrate: add test cases

pkgs/build-support/rust/build-rust-crate/test/default.nix

@@ -0,0 +1,81 @@
+{ lib, stdenv, buildRustCrate, runCommand, writeTextFile, symlinkJoin }:
+let
+  mkCrate = args: let
+      p = {
+        crateName = "nixtestcrate";
+        version = "0.1.0";
+        authors = [ "Test <test@example.com>" ];
+      } // args;
+    in buildRustCrate p;
+
+    mkFile = destination: text: writeTextFile {
+      name = "src";
+      destination = "/${destination}";
+      inherit text;
+  };
+
+  mkBin = name: mkFile name ''
+    use std::env;
+    fn main() {
+      let name: String = env::args().nth(0).unwrap();
+      println!("executed {}", name);
+    }
+  '';
+
+  mkLib = name: mkFile name "pub fn test() -> i32 { return 23; }";
+
+  mkTest = crateArgs: let
+    crate = mkCrate crateArgs;
+    binaries = map (v: ''"${v.name}"'') (crateArgs.crateBin or []);
+    isLib = crateArgs ? libName || crateArgs ? libPath;
+    crateName = crateArgs.crateName or "nixtestcrate";
+    libName = crateArgs.libName or crateName;
+
+    libTestBinary = if !isLib then null else mkCrate {
+      crateName = "run-test-${crateName}";
+      dependencies = [ crate ];
+      src = mkFile "src/main.rs" ''
+        extern crate ${libName};
+        fn main() {
+          assert_eq!(${libName}::test(), 23);
+        }
+      '';
+    };
+
+    in runCommand "run-buildRustCrate-${crateName}-test" {
+      nativeBuildInputs = [ crate ];
+    } ''
+      ${lib.concatStringsSep "\n" binaries}
+      ${lib.optionalString isLib ''
+          test -e ${crate}/lib/*.rlib || exit 1
+          ${libTestBinary}/bin/run-test-${crateName}
+      ''}
+      touch $out
+  '';
+  in rec {
+
+  tests = let
+    cases = {
+      libPath =  { libPath = "src/my_lib.rs"; src = mkLib "src/my_lib.rs"; };
+      srcLib =  { src = mkLib "src/lib.rs"; };
+      customLibName =  { libName = "test_lib"; src = mkLib "src/test_lib.rs"; };
+      customLibNameAndLibPath =  { libName = "test_lib"; libPath = "src/best-lib.rs"; src = mkLib "src/best-lib.rs"; };
+      crateBinWithPath =  { crateBin = [{ name = "test_binary1"; path = "src/foobar.rs"; }]; src = mkBin "src/foobar.rs"; };
+      crateBinNoPath1 =  { crateBin = [{ name = "my-binary2"; }]; src = mkBin "src/my_binary2.rs"; };
+      crateBinNoPath2 =  {
+        crateBin = [{ name = "my-binary3"; } { name = "my-binary4"; }];
+        src = symlinkJoin {
+          name = "buildRustCrateMultipleBinariesCase";
+          paths = [ (mkBin "src/bin/my_binary3.rs") (mkBin "src/bin/my_binary4.rs") ];
+        };
+      };
+      crateBinNoPath3 =  { crateBin = [{ name = "my-binary5"; }]; src = mkBin "src/bin/main.rs"; };
+      crateBinNoPath4 =  { crateBin = [{ name = "my-binary6"; }]; src = mkBin "src/main.rs";};
+    };
+  in lib.mapAttrs (key: value: mkTest (value // lib.optionalAttrs (!value?crateName) { crateName = key; })) cases;
+  test = runCommand "run-buildRustCrate-tests" {
+    nativeBuildInputs = builtins.attrValues tests;
+  } "
+    touch $out
+  ";
+}

pkgs/top-level/all-packages.nix

@@ -7178,6 +7178,7 @@ with pkgs;
   inherit (rust) cargo rustc;
 
   buildRustCrate = callPackage ../build-support/rust/build-rust-crate { };
+  buildRustCrateTests = recurseIntoAttrs (callPackage ../build-support/rust/build-rust-crate/test { }).tests;
 
   cargo-vendor = callPackage ../build-support/rust/cargo-vendor { };