From c66c1afaadf7714e18abef4ffeb12f3905bf3809 Mon Sep 17 00:00:00 2001
From: Christian Kampka <christian@kampka.net>
Date: Wed, 29 Dec 2021 19:07:31 +0100
Subject: [PATCH 1/2] matrix-appservice-slack: Slim down dependencies

Due to the setup of the node env and npm packages in general,
the resulting nix derivations contain a lot of unwanted dependencies.
In the the case of matrix-appservice-slack, this includes a fully
functional gcc which is required to build native bindings but is
unnecessary at runtime, as well as a full nodejs toolchain,
including tooling like npm and the like.

Switching to nodejs-slim and patching over node paths, in addition with
stripping debug symbols from native bindings, mitigates this a lot,
resulting in a massively reduced closure.
---
 .../matrix-appservice-slack/default.nix        | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/pkgs/servers/matrix-synapse/matrix-appservice-slack/default.nix b/pkgs/servers/matrix-synapse/matrix-appservice-slack/default.nix
index eb3d82e14d0b4..1ea8088967c80 100644
--- a/pkgs/servers/matrix-synapse/matrix-appservice-slack/default.nix
+++ b/pkgs/servers/matrix-synapse/matrix-appservice-slack/default.nix
@@ -1,4 +1,4 @@
-{ pkgs, nodejs, stdenv, fetchFromGitHub, lib, ... }:
+{ pkgs, nodejs, nodejs-slim, stdenv, fetchFromGitHub, lib, ... }:
 let
   src = fetchFromGitHub {
     owner = "matrix-org";
@@ -8,8 +8,9 @@ let
   };
 
   nodePackages = import ./node-composition.nix {
-    inherit pkgs nodejs;
+    inherit pkgs;
     inherit (stdenv.hostPlatform) system;
+    nodejs = nodejs-slim;
   };
 in
 nodePackages.package.override {
@@ -17,10 +18,19 @@ nodePackages.package.override {
 
   inherit src;
 
-  nativeBuildInputs = [ pkgs.makeWrapper ];
+  nativeBuildInputs = [ pkgs.makeWrapper nodejs ];
+
+  dontStrip = false;
 
   postInstall = ''
-    makeWrapper '${nodejs}/bin/node' "$out/bin/matrix-appservice-slack" \
+    # replace nodejs with nodejs-slim in node_modules
+    NODE=$(basename ${nodejs})
+    NODE_SLIM=$(basename ${nodejs-slim})
+    while read file; do
+      substituteInPlace $file --replace "$NODE" "$NODE_SLIM"
+    done < <(grep -l -R "$NODE" $out/lib )
+
+    makeWrapper '${nodejs-slim}/bin/node' "$out/bin/matrix-appservice-slack" \
     --add-flags "$out/lib/node_modules/matrix-appservice-slack/lib/app.js"
   '';
 

From 2b91dfd19b838005c8b6af71cfc7509d40d5d319 Mon Sep 17 00:00:00 2001
From: Christian Kampka <christian@kampka.net>
Date: Wed, 29 Dec 2021 19:26:42 +0100
Subject: [PATCH 2/2] matrix-appservice-slack: Add simple test

---
 .../matrix-appservice-slack/default.nix               | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/pkgs/servers/matrix-synapse/matrix-appservice-slack/default.nix b/pkgs/servers/matrix-synapse/matrix-appservice-slack/default.nix
index 1ea8088967c80..bd4de337b1226 100644
--- a/pkgs/servers/matrix-synapse/matrix-appservice-slack/default.nix
+++ b/pkgs/servers/matrix-synapse/matrix-appservice-slack/default.nix
@@ -1,4 +1,4 @@
-{ pkgs, nodejs, nodejs-slim, stdenv, fetchFromGitHub, lib, ... }:
+{ pkgs, nodejs, nodejs-slim, stdenv, fetchFromGitHub, lib, runCommand, matrix-appservice-slack }:
 let
   src = fetchFromGitHub {
     owner = "matrix-org";
@@ -12,9 +12,9 @@ let
     inherit (stdenv.hostPlatform) system;
     nodejs = nodejs-slim;
   };
+  pname = "matrix-appservice-slack";
 in
 nodePackages.package.override {
-  pname = "matrix-appservice-slack";
 
   inherit src;
 
@@ -34,6 +34,13 @@ nodePackages.package.override {
     --add-flags "$out/lib/node_modules/matrix-appservice-slack/lib/app.js"
   '';
 
+  passthru.tests = {
+    simple = runCommand "${pname}-test" {} ''
+      ${matrix-appservice-slack}/bin/matrix-appservice-slack --help > $out
+      [ -s $out ]
+    '';
+  };
+
   meta = with lib; {
     description = "A Matrix <--> Slack bridge";
     maintainers = with maintainers; [ beardhatcode ];