From 372410046b1f176074f2f3b18df6a54e1fea0436 Mon Sep 17 00:00:00 2001
From: Patryk Wychowaniec <pwychowaniec@pm.me>
Date: Thu, 17 Aug 2023 12:39:58 +0200
Subject: [PATCH] Fix support for `.cargo/config`

Before https://github.com/nix-community/naersk/pull/300, our
`builtinz.toTOML` used to return a string representing the serialized
document which was later redirected into a file:

https://github.com/nix-community/naersk/pull/300/files#diff-b6b537316f2d29c8faf178a110366796811d1bc72f694262c7d2efad79aa984bL238

Over that merge request, this was changed to return a path, to make it
consistent with how nixpkgs' formatters work - but I haven't noticed one
place that still _read_ the file instead of returning a path (which was
fine before, since the code did `echo ... > ...`, but is not a correct
thing to do for `cp`).

Closes https://github.com/nix-community/naersk/issues/305.
---
 default.nix                                   |  2 +-
 test/fast/cargo-config/default.nix            | 20 +++++++++++++++++++
 test/fast/cargo-config/fixtures/.cargo/config |  2 ++
 test/fast/cargo-config/fixtures/Cargo.lock    |  7 +++++++
 test/fast/cargo-config/fixtures/Cargo.toml    |  4 ++++
 test/fast/cargo-config/fixtures/src/main.rs   | 11 ++++++++++
 test/fast/default.nix                         |  1 +
 7 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 test/fast/cargo-config/default.nix
 create mode 100644 test/fast/cargo-config/fixtures/.cargo/config
 create mode 100644 test/fast/cargo-config/fixtures/Cargo.lock
 create mode 100644 test/fast/cargo-config/fixtures/Cargo.toml
 create mode 100644 test/fast/cargo-config/fixtures/src/main.rs

diff --git a/default.nix b/default.nix
index 61b44ec..a377938 100644
--- a/default.nix
+++ b/default.nix
@@ -31,7 +31,7 @@ let
         libb.findGitDependencies { inherit (config) cargolock gitAllRefs gitSubmodules; };
       cargoconfig =
         if builtinz.pathExists (toString config.root + "/.cargo/config")
-        then builtins.readFile (config.root + "/.cargo/config")
+        then (config.root + "/.cargo/config")
         else null;
       build = args: import ./build.nix (
         {
diff --git a/test/fast/cargo-config/default.nix b/test/fast/cargo-config/default.nix
new file mode 100644
index 0000000..51fffbf
--- /dev/null
+++ b/test/fast/cargo-config/default.nix
@@ -0,0 +1,20 @@
+{ sources, pkgs, ... }:
+
+let
+  fenix = import sources.fenix { };
+
+  # Support for custom environmental variables was introduced in Cargo 1.56 and
+  # our tests use nixpkgs-21.05 which contains an older version of Cargo, making
+  # this test fail otherwise.
+  toolchain = fenix.latest;
+
+  naersk = pkgs.callPackage ../../../default.nix {
+    cargo = toolchain.cargo;
+    rustc = toolchain.rustc;
+  };
+
+in
+naersk.buildPackage {
+  src = ./fixtures;
+  doCheck = true;
+}
diff --git a/test/fast/cargo-config/fixtures/.cargo/config b/test/fast/cargo-config/fixtures/.cargo/config
new file mode 100644
index 0000000..ac0cce0
--- /dev/null
+++ b/test/fast/cargo-config/fixtures/.cargo/config
@@ -0,0 +1,2 @@
+[env]
+ENV_HELLO_WORLD="Hello, World!"
diff --git a/test/fast/cargo-config/fixtures/Cargo.lock b/test/fast/cargo-config/fixtures/Cargo.lock
new file mode 100644
index 0000000..c469709
--- /dev/null
+++ b/test/fast/cargo-config/fixtures/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "cargo-config"
+version = "0.1.0"
diff --git a/test/fast/cargo-config/fixtures/Cargo.toml b/test/fast/cargo-config/fixtures/Cargo.toml
new file mode 100644
index 0000000..352659f
--- /dev/null
+++ b/test/fast/cargo-config/fixtures/Cargo.toml
@@ -0,0 +1,4 @@
+[package]
+name = "cargo-config"
+version = "0.1.0"
+edition = "2018"
diff --git a/test/fast/cargo-config/fixtures/src/main.rs b/test/fast/cargo-config/fixtures/src/main.rs
new file mode 100644
index 0000000..c11d46f
--- /dev/null
+++ b/test/fast/cargo-config/fixtures/src/main.rs
@@ -0,0 +1,11 @@
+fn main() {
+    println!("{}", env!("ENV_HELLO_WORLD"));
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test() {
+        assert_eq!("Hello, World!", env!("ENV_HELLO_WORLD"));
+    }
+}
diff --git a/test/fast/default.nix b/test/fast/default.nix
index 18582e4..ee063b2 100644
--- a/test/fast/default.nix
+++ b/test/fast/default.nix
@@ -1,4 +1,5 @@
 args: {
+  cargo-config = import ./cargo-config args;
   cargo-wildcard = import ./cargo-wildcard args;
   default-run = import ./default-run args;
   dummyfication = import ./dummyfication args;